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Sample records for rapid heart beat

  1. The heart that beats

    Directory of Open Access Journals (Sweden)

    Kashvi Gupta, MBBS

    2017-03-01

    Full Text Available An intern narrates her encounter with a 19 year old girl recently diagnosed with giant cell myocarditis and shortlisted for a heart transplant. Inspired by the young girl’s eagerness to live despite the looming difficulties inherent in the future of a transplant recipient, she reflects on her own life and comes to an understanding of why heart transplant surgery, despite making people dependent on life-long medication, also, more importantly, gives them another chance at life.

  2. Directional Estimation for Robotic Beating Heart Surgery

    OpenAIRE

    Kurz, Gerhard

    2015-01-01

    In robotic beating heart surgery, a remote-controlled robot can be used to carry out the operation while automatically canceling out the heart motion. The surgeon controlling the robot is shown a stabilized view of the heart. First, we consider the use of directional statistics for estimation of the phase of the heartbeat. Second, we deal with reconstruction of a moving and deformable surface. Third, we address the question of obtaining a stabilized image of the heart.

  3. Correlations in heart beat data as quantitative characterization of heart pathology

    Energy Technology Data Exchange (ETDEWEB)

    Ulbikas, J.; Cenys, A. [Semiconductor Physics Institute, Gostauto 11, 2600 Vilnius (Lithuania); Zemaityte, D.; Varoneckas, G. [Institute of Psychophysiology and Rehabilitation, Vyduno 4, 5720 Palanga (Lithuania)

    1996-06-01

    Correlation between heart pathology and statistical properties of heart beat data has been studied. It is shown that heart beat data has different scaling behavior for healthy and disease cases. Possibilities to develop new monitoring technique based on the permanent control of the correlations in heart beat data are discussed. {copyright} {ital 1996 American Institute of Physics.}

  4. Reversed-J inferior sternotomy for beating heart coronary surgery

    NARCIS (Netherlands)

    Grandjean, JG; Canosa, C; Mariani, MA; Boonstra, PW

    Median sternotomy or combined multiple minimally invasive approaches are currently used to revascularize patients with multivessel coronary artery disease on the beating heart. We present here a new alternative approach for minimally invasive coronary surgery on the beating heart: the reversed-J

  5. Robotic tissue tracking for beating heart mitral valve surgery.

    Science.gov (United States)

    Yuen, Shelten G; Vasilyev, Nikolay V; del Nido, Pedro J; Howe, Robert D

    2013-12-01

    The rapid motion of the heart presents a significant challenge to the surgeon during intracardiac beating heart procedures. We present a 3D ultrasound-guided motion compensation system that assists the surgeon by synchronizing instrument motion with the heart. The system utilizes the fact that certain intracardiac structures, like the mitral valve annulus, have trajectories that are largely constrained to translation along one axis. This allows the development of a real-time 3D ultrasound tissue tracker that we integrate with a 1 degree-of-freedom (DOF) actuated surgical instrument and predictive filter to devise a motion tracking system adapted to mitral valve annuloplasty. In vivo experiments demonstrate that the system provides highly accurate tracking (1.0 mm error) with 70% less error than manual tracking attempts. Copyright © 2010 Elsevier B.V. All rights reserved.

  6. Robust Detection of Heart Beats in Multimodal Data

    OpenAIRE

    Aliyev, Taghi

    2017-01-01

    Final report of the 'Robust Heart Beat Detection in Multimodal Data' as part of the Masters in Operations Research. Project was done together with other group members, as can be found in the report itself.

  7. Heart Motion Prediction in Robotic-Assisted Beating Heart Surgery: A Nonlinear Fast Adaptive Approach

    OpenAIRE

    Fan Liang; Yang Yu; Haizhong Wang; Xiaofeng Meng

    2013-01-01

    Off-pump Coronary Artery Bypass Graft (CABG) surgery outperforms traditional on-pump surgery because the assisted robotic tools can alleviate the relative motion between the beating heart and robotic tools. Therefore, it is possible for the surgeon to operate on the beating heart and thus lessens post surgery complications for the patients. Due to the highly irregular and non-stationary nature of heart motion, it is critical that the beating heart motion is predicted in the model-based track ...

  8. Non-heart-beating donation in Spain.

    Science.gov (United States)

    Gomez-de-Antonio, David; Varela, Andres

    2011-01-01

    The aim of our study was to describe our protocol of non-heart-beating-donor (NHBD) lung transplantation and discuss data regarding the situation of NHBD and lung transplantation in Spain. Experimental work regarding NHBD led our National Organization of Transplants to develop several working groups with the objective of investigating the possibility of using uncontrolled NHBD in our country. This turned into a flexible and useful legal mechanism that allowed immediate judicial permission to preserve-and harvest-those organs. Several harvesting programs for mainly abdominal organs (kidney and liver) started in Spain during the late 1980s, with good mid-term results. The collaboration between two hospitals in Madrid-Hospital Clinico San Carlos and Hospital Puerta de Hierro as transplantation hospital-led to the development of a successful NHBD lung program for uncontrolled donors that is a pioneer in the world. In Spain, donation after cardiac arrest represents 6.7% of all transplants, mainly from types I (dead on arrival) and II (unsuccessful resuscitation) donors. NHBD for lung transplantation is concentrated in Madrid, with approximately 60 potential NHBDs per year. With this additional source of organs we have so far been able to perform 32 lung transplantations, which represents an increase of 13% of our annual transplantation rates. NHBD is no longer just a promising source of organs for lung transplantations, it is a real one. We hope that in the near future many other units will develop similar protocols to improve the use of these grafts and decrease the mortality rate among those on the waiting lists.

  9. Non-heart beating organ donation : overview and future perspectives

    NARCIS (Netherlands)

    Moers, Cyril; Leuvenink, Henri G. D.; Ploeg, Rutger J.

    New indications for organ transplantation combined with a stagnating number of available donor grafts have severely lengthened the waiting list for almost all types of transplantations. This has led to a renewed interest in non-heart beating (NHB) donation, as a possible solution to bridge the gap

  10. Analysis of heart rate variability in the presence of ectopic beats using the heart timing signal.

    Science.gov (United States)

    Mateo, Javier; Laguna, Pablo

    2003-03-01

    The time-domain signals representing the heart rate variability (HRV) in the presence of an ectopic beat exhibit a sharp transient at the position of the ectopic beat, which corrupts the signal, particularly the power spectral density (PSD) of the HRV. Consequently, there is a need for correction of this type of beat prior to any HRV analysis. This paper deals with the PSD estimation of the HRV by means of the heart timing (HT) signal when ectopic beats are present. These beat occurrence times are modeled from a generalized, continuous time integral pulse frequency modulation model and, from this point of view, a specific method for minimizing the effect of the presence of ectopic beats is presented to work together with the HT signal. By using both, a white noise driven autoregressive model of the HRV signal with artificially introduced ectopic beats and actual heart rate series including ectopic beats, the more usual methods of HRV spectral estimation are compared. Results of the PSD estimation error function of the number of ectopic beats are presented. These results demonstrate that the proposed method has one order of magnitude lower error than usual ectopic beats removal strategies in preserving PSD, thus, this strategy better recovers the original clinical indexes of interest.

  11. Enhancing Heart-Beat-Based Security for mHealth Applications

    NARCIS (Netherlands)

    Seepers, Robert M; Strydis, Christos; Sourdis, Ioannis; De Zeeuw, Chris I

    In heart-beat-based security, a security key is derived from the time difference between consecutive heart beats (the inter-pulse interval, IPI), which may, subsequently, be used to enable secure communication. While heart-beat-based security holds promise in mobile health (mHealth) applications,

  12. Connection forms for beating the heart

    DEFF Research Database (Denmark)

    Mensch, Arthur; Piuze, Emmanuel; Lehnert, Lucas

    2014-01-01

    We combine recent work on modeling cardiac mechanics using a finite volume method with the insight that heart wall myofiber orientations exhibit a particular volumetric geometry. In our finite vol- ume mechanical simulation we use Maurer-Cartan one-forms to add a geometrical consistency term...... to control the rate at which myofiber ori- entation changes in the direction perpendicular to the heart wall. This allows us to estimate material properties related to both the passive and active parameters in our model. We have obtained preliminary results on the 4 canine datasets of the 2014 mechanics...... challenge using the FEBio software suite. In ongoing work we are validating and improving the model using rat heart (ex-vivo DTI and in-vivo tagging) MRI datasets, from which we have estimated strain tensors....

  13. Towards active tracking of beating heart motion in the presence of arrhythmia for robotic assisted beating heart surgery.

    Science.gov (United States)

    Tuna, E Erdem; Karimov, Jamshid H; Liu, Taoming; Bebek, Özkan; Fukamachi, Kiyotaka; Çavuşoğlu, M Cenk

    2014-01-01

    In robotic assisted beating heart surgery, the control architecture for heart motion tracking has stringent requirements in terms of bandwidth of the motion that needs to be tracked. In order to achieve sufficient tracking accuracy, feed-forward control algorithms, which rely on estimations of upcoming heart motion, have been proposed in the literature. However, performance of these feed-forward motion control algorithms under heart rhythm variations is an important concern. In their past work, the authors have demonstrated the effectiveness of a receding horizon model predictive control-based algorithm, which used generalized adaptive predictors, under constant and slowly varying heart rate conditions. This paper extends these studies to the case when the heart motion statistics change abruptly and significantly, such as during arrhythmias. A feasibility study is carried out to assess the motion tracking capabilities of the adaptive algorithms in the occurrence of arrhythmia during beating heart surgery. Specifically, the tracking performance of the algorithms is evaluated on prerecorded motion data, which is collected in vivo and includes heart rhythm irregularities. The algorithms are tested using both simulations and bench experiments on a three degree-of-freedom robotic test bed. They are also compared with a position-plus-derivative controller as well as a receding horizon model predictive controller that employs an extended Kalman filter algorithm for predicting future heart motion.

  14. Towards active tracking of beating heart motion in the presence of arrhythmia for robotic assisted beating heart surgery.

    Directory of Open Access Journals (Sweden)

    E Erdem Tuna

    Full Text Available In robotic assisted beating heart surgery, the control architecture for heart motion tracking has stringent requirements in terms of bandwidth of the motion that needs to be tracked. In order to achieve sufficient tracking accuracy, feed-forward control algorithms, which rely on estimations of upcoming heart motion, have been proposed in the literature. However, performance of these feed-forward motion control algorithms under heart rhythm variations is an important concern. In their past work, the authors have demonstrated the effectiveness of a receding horizon model predictive control-based algorithm, which used generalized adaptive predictors, under constant and slowly varying heart rate conditions. This paper extends these studies to the case when the heart motion statistics change abruptly and significantly, such as during arrhythmias. A feasibility study is carried out to assess the motion tracking capabilities of the adaptive algorithms in the occurrence of arrhythmia during beating heart surgery. Specifically, the tracking performance of the algorithms is evaluated on prerecorded motion data, which is collected in vivo and includes heart rhythm irregularities. The algorithms are tested using both simulations and bench experiments on a three degree-of-freedom robotic test bed. They are also compared with a position-plus-derivative controller as well as a receding horizon model predictive controller that employs an extended Kalman filter algorithm for predicting future heart motion.

  15. Heart Motion Prediction in Robotic-Assisted Beating Heart Surgery: A Nonlinear Fast Adaptive Approach

    National Research Council Canada - National Science Library

    Liang, Fan; Yu, Yang; Wang, Haizhong; Meng, Xiaofeng

    2013-01-01

    Off-pump Coronary Artery Bypass Graft (CABG) surgery outperforms traditional on-pump surgery because the assisted robotic tools can alleviate the relative motion between the beating heart and robotic tools...

  16. Multivariate Autoregressive Model Based Heart Motion Prediction Approach for Beating Heart Surgery

    Directory of Open Access Journals (Sweden)

    Fan Liang

    2013-02-01

    Full Text Available A robotic tool can enable a surgeon to conduct off-pump coronary artery graft bypass surgery on a beating heart. The robotic tool actively alleviates the relative motion between the point of interest (POI on the heart surface and the surgical tool and allows the surgeon to operate as if the heart were stationary. Since the beating heart's motion is relatively high-band, with nonlinear and nonstationary characteristics, it is difficult to follow. Thus, precise beating heart motion prediction is necessary for the tracking control procedure during the surgery. In the research presented here, we first observe that Electrocardiography (ECG signal contains the causal phase information on heart motion and non-stationary heart rate dynamic variations. Then, we investigate the relationship between ECG signal and beating heart motion using Granger Causality Analysis, which describes the feasibility of the improved prediction of heart motion. Next, we propose a nonlinear time-varying multivariate vector autoregressive (MVAR model based adaptive prediction method. In this model, the significant correlation between ECG and heart motion enables the improvement of the prediction of sharp changes in heart motion and the approximation of the motion with sufficient detail. Dual Kalman Filters (DKF estimate the states and parameters of the model, respectively. Last, we evaluate the proposed algorithm through comparative experiments using the two sets of collected vivo data.

  17. Ion channels and beating heart: the players and the music

    Directory of Open Access Journals (Sweden)

    Charles Antzelevitch

    2011-12-01

    Full Text Available Soft gentle music accompanies us throughout our lifetime; it is the music of our heart beating. Although at times it is questionable as to who serves as conductor of the orchestra, there is little doubt that our ion channels are the main players. Whenever one of them plays too loudly, too softly or simply off key, disharmony results, sometimes leading to total disruption of the rate and rhythm. Ion channels can disrupt the music of our heart by different mechanisms. Sometimes their function is correct, but their expression is altered by underlying cardiac diseases (i.e. heart failure; sometimes the defect is in their structure, because of an underlying genetic defect, and in this case a channelopathy is present.

  18. In vivo electroporation mediated gene delivery to the beating heart.

    Directory of Open Access Journals (Sweden)

    Erick L Ayuni

    Full Text Available Gene therapy may represent a promising alternative strategy for cardiac muscle regeneration. In vivo electroporation, a physical method of gene transfer, has recently evolved as an efficient method for gene transfer. In the current study, we investigated the efficiency and safety of a protocol involving in vivo electroporation for gene transfer to the beating heart. Adult male rats were anesthetised and the heart exposed through a left thoracotomy. Naked plasmid DNA was injected retrograde into the transiently occluded coronary sinus before the electric pulses were applied. Animals were sacrificed at specific time points and gene expression was detected. Results were compared to the group of animals where no electric pulses were applied. No post-procedure arrhythmia was observed. Left ventricular function was temporarily altered only in the group were high pulses were applied; CK-MB (Creatine kinase and TNT (Troponin T were also altered only in this group. Histology showed no signs of toxicity. Gene expression was highest at day one. Our results provide evidence that in vivo electroporation with an optimized protocol is a safe and effective tool for nonviral gene delivery to the beating heart. This method may be promising for clinical settings especially for perioperative gene delivery.

  19. Heart Motion Prediction in Robotic-Assisted Beating Heart Surgery: A Nonlinear Fast Adaptive Approach

    Directory of Open Access Journals (Sweden)

    Fan Liang

    2013-01-01

    Full Text Available Off-pump Coronary Artery Bypass Graft (CABG surgery outperforms traditional on-pump surgery because the assisted robotic tools can alleviate the relative motion between the beating heart and robotic tools. Therefore, it is possible for the surgeon to operate on the beating heart and thus lessens post surgery complications for the patients. Due to the highly irregular and non-stationary nature of heart motion, it is critical that the beating heart motion is predicted in the model-based track control procedures. It is technically preferable to model heart motion in a nonlinear way because the characteristic analysis of 3D heart motion data through Bi-spectral analysis and Fourier methods demonstrates the involved nonlinearity of heart motion. We propose an adaptive nonlinear heart motion model based on the Volterra Series in this paper. We also design a fast lattice structure to achieve computational-efficiency for real-time online predictions. We argue that the quadratic term of the Volterra Series can improve the prediction accuracy by covering sharp change points and including the motion with sufficient detail. The experiment results indicate that the adaptive nonlinear heart motion prediction algorithm outperforms the autoregressive (AR and the time-varying Fourier-series models in terms of the root mean square of the prediction error and the prediction error in extreme cases.

  20. Peak misdetection in heart-beat-based security : Characterization and tolerance

    NARCIS (Netherlands)

    Seepers, Robert M; Strydis, Christos; Peris-Lopez, Pedro; Sourdis, Ioannis; De Zeeuw, Chris I

    The Inter-Pulse-Interval (IPI) of heart beats has previously been suggested for security in mobile health (mHealth) applications. In IPI-based security, secure communication is facilitated through a security key derived from the time difference between heart beats. However, there currently exists no

  1. The first non-heart-beating organ donor in Hawaii--medical and ethical considerations.

    Science.gov (United States)

    Cheung, A H; Kailani, H K; Limm, W M

    2000-09-01

    The shortage of organ donors remains a major obstacle in transplantation in Hawaii. Some patients die while waiting for a life-saving organ. Across the nation, "marginal" donors, including non-heart-beating donors are used. The authors describe the first successful non-heart-beating organ donor transplant in Hawaii, and include medical and ethical considerations.

  2. Non-heart beating organ donation: overview and future perspectives.

    Science.gov (United States)

    Moers, Cyril; Leuvenink, Henri G D; Ploeg, Rutger J

    2007-07-01

    New indications for organ transplantation combined with a stagnating number of available donor grafts have severely lengthened the waiting list for almost all types of transplantations. This has led to a renewed interest in non-heart beating (NHB) donation, as a possible solution to bridge the gap between supply and demand. In this review, we present an overview of current NHB donation practice, outcome, existing problems and future perspectives. We focus on possible improvements in donor management, recipient care and new methods of organ preservation that may be better suited for these marginal organs. Successful institution of NHB protocols depends on adapting current transplantation practice at all levels, which is one of the greatest challenges for researchers and professionals in this interesting re-emerging field.

  3. Autoregulation of coronary blood flow in the isolated beating pig heart.

    Science.gov (United States)

    Schampaert, Stéphanie; van 't Veer, Marcel; Rutten, Marcel C M; van Tuijl, Sjoerd; de Hart, Jurgen; van de Vosse, Frans N; Pijls, Nico H J

    2013-08-01

    The isolated beating pig heart model is an accessible platform to investigate the coronary circulation in its truly morphological and physiological state, whereas its use is beneficial from a time, cost, and ethical perspective. However, whether the coronary autoregulation is still intact is not known. Here, we study the autoregulation of coronary blood flow in the working isolated pig heart in response to brief occlusions of the coronary artery, to step-wise changes in left ventricular loading conditions and contractile states, and to pharmacologic vasodilating stimuli. Six slaughterhouse pig hearts (473 ± 40 g) were isolated, prepared, and connected to an external circulatory system. Through coronary reperfusion and controlled cardiac loading, physiological cardiac performance was achieved. After release of a coronary occlusion, coronary blood flow rose rapidly to an equal (maximum) level as the flow during control beats, independent of the duration of occlusion. Moreover, a linear relation was found between coronary blood flow and coronary driving pressure for a wide variation of preload, afterload, and contractility. In addition, intracoronary administration of papaverine did not yield a transient increase in blood flow indicating the presence of maximum coronary hyperemia. Together, this indicates that the coronary circulation in the isolated beating pig heart is in a permanent state of maximum hyperemia. This makes the model excellently suitable for testing and validating cardiovascular devices (i.e., heart valves, stent grafts, and ventricular assist devices) under well-controlled circumstances, whereas it decreases the necessity of sacrificing large mammalians for performing classical animal experiments. © 2013, Copyright the Authors. Artificial Organs © 2013 Wiley Periodicals, Inc. and International Center for Artificial Organs and Transplantation.

  4. A Quadratic Nonlinear Prediction-Based Heart Motion Model Following Control Algorithm in Robotic-Assisted Beating Heart Surgery

    OpenAIRE

    Fan Liang; Xiaofeng Meng

    2013-01-01

    Off-pump coronary artery bypass graft surgery outperforms the traditional on-pump surgery because the assisted robotic tools can cancel the relative motion between the beating heart and the robotic tools, which reduces post-surgery complications for patients. The challenge for the robot assisted tool when tracking the beating heart is the abrupt change caused by the nonlinear nature of heart motion and high precision surgery requirements. A characteristic analysis of 3D heart motion data thro...

  5. Estimating 'lost heart beats' rather than reductions in heart rate during the intubation of critically-ill children.

    Science.gov (United States)

    Jones, Peter; Ovenden, Nick; Dauger, Stéphane; Peters, Mark J

    2014-01-01

    Reductions in heart rate occur frequently in children during critical care intubation and are currently considered the gold standard for haemodynamic instability. Our objective was to estimate loss of heart beats during intubation and compare this to reduction in heart rate alone whilst testing the impact of atropine pre-medication. Data were extracted from a prospective 2-year cohort study of intubation ECGs from critically ill children in PICU/Paediatric Transport. A three step algorithm was established to exclude variation in pre-intubation heart rate (using a 95%CI limit derived from pre-intubation heart rate variation of the children included), measure the heart rate over time and finally the estimate the numbers of lost beats. 333 intubations in children were eligible for inclusion of which 245 were available for analysis (74%). Intubations where the fall in heart rate was less than 50 bpm were accompanied almost exclusively by less than 25 lost beats (n = 175, median 0 [0-1]). When there was a reduction of >50 bpm there was a poor correlation with numbers of lost beats (n = 70, median 42 [15-83]). During intubation the median number of lost beats was 8 [1]-[32] when atropine was not used compared to 0 [0-0] when atropine was used (pheart rate during intubation of heart rate was >50 bpm the heart rate was poorly predictive of lost beats. A study looking at the relationship between lost beats and cardiac output needs to be performed. Atropine reduces both fall in heart rate and loss of beats. Similar area-under-the-curve methodology may be useful for estimating risk when biological parameters deviate outside normal range.

  6. Autonomic Modulation in Patients with Heart Failure Increases Beat-to-Beat Variability of Ventricular Action Potential Duration.

    Science.gov (United States)

    Porter, Bradley; Bishop, Martin J; Claridge, Simon; Behar, Jonathan; Sieniewicz, Benjamin J; Webb, Jessica; Gould, Justin; O'Neill, Mark; Rinaldi, Christopher A; Razavi, Reza; Gill, Jaswinder S; Taggart, Peter

    2017-01-01

    Background: Exaggerated beat-to-beat variability of ventricular action potential duration (APD) is linked to arrhythmogenesis. Sympathetic stimulation has been shown to increase QT interval variability, but its effect on ventricular APD in humans has not been determined. Methods and Results: Eleven heart failure patients with implanted bi-ventricular pacing devices had activation-recovery intervals (ARI, surrogate for APD) recorded from LV epicardial electrodes under constant RV pacing. Sympathetic activity was increased using a standard autonomic challenge (Valsalva) and baroreceptor indices were applied to determine changes in sympathetic stimulation. Two Valsalvas were performed for each study and were repeated, both off and on bisoprolol. In addition sympathetic nerve activity (SNA) was measured from skin electrodes on the thorax using a novel validated method. Autonomic modulation significantly increased mean short-term variability in ARI; off bisoprolol mean STV increased from 3.73 ± 1.3 to 5.27 ± 1.04 ms ( p = 0.01), on bisoprolol mean STV of ARI increased from 4.15 ± 1.14 to 4.62 ± 1 ms ( p = 0.14). Adrenergic indices of the Valsalva demonstrated significantly reduced beta-adrenergic function when on bisoprolol (Δ pressure recovery time, p = 0.04; Δ systolic overshoot in Phase IV, p = 0.05). Corresponding increases in SNA from rest both off (1.4 uV, p < 0.01) and on (0.7 uV, p < 0.01) bisoprolol were also seen. Conclusions: Beat-to-beat variability of ventricular APD increases during brief periods of increased sympathetic activity in patients with heart failure. Bisoprolol reduces, but does not eliminate, these effects. This may be important in the genesis of ventricular arrhythmias in heart failure patients.

  7. Low-Cost, Take-Home, Beating Heart Simulator for Health-Care Education

    OpenAIRE

    Berg, Devin

    2013-01-01

    Abstract: Intended for medical students studying the evaluation and diagnosis of heart arrhythmias, the beating heart arrhythmia simulator combines visual, auditory, and tactile stimuli to enhance the student's retention of the subtle differences between various conditions of the heart necessary for diagnosis. Unlike existing heart arrhythmia simulators, our simulator is low cost and easily deployable in the classroom setting. A design consisting of solenoid actuators, a silicon heart mode...

  8. A Quadratic Nonlinear Prediction-Based Heart Motion Model following Control Algorithm in Robotic-Assisted Beating Heart Surgery

    National Research Council Canada - National Science Library

    Liang, Fan; Meng, Xiaofeng

    2013-01-01

    Off-pump coronary artery bypass graft surgery outperforms the traditional on-pump surgery because the assisted robotic tools can cancel the relative motion between the beating heart and the robotic...

  9. Efficient physics-based tracking of heart surface motion for beating heart surgery robotic systems.

    Science.gov (United States)

    Bogatyrenko, Evgeniya; Pompey, Pascal; Hanebeck, Uwe D

    2011-05-01

    Tracking of beating heart motion in a robotic surgery system is required for complex cardiovascular interventions. A heart surface motion tracking method is developed, including a stochastic physics-based heart surface model and an efficient reconstruction algorithm. The algorithm uses the constraints provided by the model that exploits the physical characteristics of the heart. The main advantage of the model is that it is more realistic than most standard heart models. Additionally, no explicit matching between the measurements and the model is required. The application of meshless methods significantly reduces the complexity of physics-based tracking. Based on the stochastic physical model of the heart surface, this approach considers the motion of the intervention area and is robust to occlusions and reflections. The tracking algorithm is evaluated in simulations and experiments on an artificial heart. Providing higher accuracy than the standard model-based methods, it successfully copes with occlusions and provides high performance even when all measurements are not available. Combining the physical and stochastic description of the heart surface motion ensures physically correct and accurate prediction. Automatic initialization of the physics-based cardiac motion tracking enables system evaluation in a clinical environment.

  10. Reduced ischemia-reperfusion injury with isoproterenol in non-heart-beating donor lungs.

    Science.gov (United States)

    Jones, D R; Hoffmann, S C; Sellars, M; Egan, T M

    1997-05-01

    Transplantation of lungs retrieved from non-heart-beating donors could expand the donor pool. Recent studies suggest that the ischemia-reperfusion injury (IRI) to the lung can be attenuated by increasing intracellular cAMP concentrations. The purpose of this study was to determine the effect of IRI on capillary permeability, as measured by Kfc, in lungs retrieved from non-heart-beating donors and reperfused with or without isoproterenol (iso). Using an in situ isolated perfused lung model, lungs were retrieved from non-heart-beating donor rats ventilated with O2 or not at varying intervals after death. The lungs were reperfused with or without iso (10 microM). Kfc, lung viability, and pulmonary hemodynamics were measured, and tissue levels of adenine nucleotides and cAMP were measured by HPLC. Iso-reperfusion decreased Kfc significantly (P Kfc in non-iso-reperfused (r = 0.65) and iso-perfused (r = 0.84) lungs. cAMP levels increased significantly with iso-reperfusion. cAMP levels correlated with Kfc (r = 0.87) in iso-reperfused lungs. Iso-reperfusion of lungs retrieved from non-heart-beating donor rats results in decreased capillary permeability and increased lung tissue cAMP levels. Pharmacologic augmentation of tissue TAN and cAMP levels may further ameliorate the increased capillary permeability seen in lungs retrieved from non-heart-beating donors.

  11. Speckle variance optical coherence tomography of blood flow in the beating mouse embryonic heart.

    Science.gov (United States)

    Grishina, Olga A; Wang, Shang; Larina, Irina V

    2017-05-01

    Efficient separation of blood and cardiac wall in the beating embryonic heart is essential and critical for experiment-based computational modelling and analysis of early-stage cardiac biomechanics. Although speckle variance optical coherence tomography (SV-OCT) relying on calculation of intensity variance over consecutively acquired frames is a powerful approach for segmentation of fluid flow from static tissue, application of this method in the beating embryonic heart remains challenging because moving structures generate SV signal indistinguishable from the blood. Here, we demonstrate a modified four-dimensional SV-OCT approach that effectively separates the blood flow from the dynamic heart wall in the beating mouse embryonic heart. The method takes advantage of the periodic motion of the cardiac wall and is based on calculation of the SV signal over the frames corresponding to the same phase of the heartbeat cycle. Through comparison with Doppler OCT imaging, we validate this speckle-based approach and show advantages in its insensitiveness to the flow direction and velocity as well as reduced influence from the heart wall movement. This approach has a potential in variety of applications relying on visualization and segmentation of blood flow in periodically moving structures, such as mechanical simulation studies and finite element modelling. Picture: Four-dimensional speckle variance OCT imaging shows the blood flow inside the beating heart of an E8.5 mouse embryo. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  12. Heart motion uncertainty compensation prediction method for robot assisted beating heart surgery - Master-slave Kalman Filters approach.

    Science.gov (United States)

    Liang, Fan; Yu, Yang; Cui, Shigang; Zhao, Li; Wu, Xingli

    2014-05-01

    Robot Assisted Coronary Artery Bypass Graft (CABG) allows the heart keep beating in the surgery by actively eliminating the relative motion between point of interest (POI) on the heart surface and surgical tool. The inherited nonlinear and diverse nature of beating heart motion gives a huge obstacle for the robot to meet the demanding tracking control requirements. In this paper, we novelty propose a Master-slave Kalman Filter based on beating heart motion Nonlinear Adaptive Prediction (NAP) algorithm. In the study, we describe the beating heart motion as the combination of nonlinearity relating mathematics part and uncertainty relating non-mathematics part. Specifically, first, we model the nonlinearity of the heart motion via quadratic modulated sinusoids and estimate it by a Master Kalman Filter. Second, we involve the uncertainty heart motion by adaptively change the covariance of the process noise through the slave Kalman Filter. We conduct comparative experiments to evaluate the proposed approach with four distinguished datasets. The results indicate that the new approach reduces prediction errors by at least 30 μm. Moreover, the new approach performs well in robustness test, in which two kinds of arrhythmia datasets from MIT-BIH arrhythmia database are assessed.

  13. Low-cost, take-home, beating heart simulator for health-care education.

    Science.gov (United States)

    Berg, Devin R; Carlson, Andrew; Durfee, William K; Sweet, Robert M; Reihsen, Troy

    2011-01-01

    Intended for medical students studying the evaluation and diagnosis of heart arrhythmias, the beating heart arrhythmia simulator combines visual, auditory, and tactile stimuli to enhance the student's retention of the subtle differences between various conditions of the heart necessary for diagnosis. Unlike existing heart arrhythmia simulators, our simulator is low cost and easily deployable in the classroom setting. A design consisting of solenoid actuators, a silicon heart model, and a graphical user interface has been developed and prototyped. Future design development and conceptual validation is necessary prior to deployment.

  14. Enhancing Heart-Beat-Based Security for mHealth Applications.

    Science.gov (United States)

    Seepers, Robert M; Strydis, Christos; Sourdis, Ioannis; De Zeeuw, Chris I

    2017-01-01

    In heart-beat-based security, a security key is derived from the time difference between consecutive heart beats (the inter-pulse interval, IPI), which may, subsequently, be used to enable secure communication. While heart-beat-based security holds promise in mobile health (mHealth) applications, there currently exists no work that provides a detailed characterization of the delivered security in a real system. In this paper, we evaluate the strength of IPI-based security keys in the context of entity authentication. We investigate several aspects that should be considered in practice, including subjects with reduced heart-rate variability (HRV), different sensor-sampling frequencies, intersensor variability (i.e., how accurate each entity may measure heart beats) as well as average and worst-case-authentication time. Contrary to the current state of the art, our evaluation demonstrates that authentication using multiple, less-entropic keys may actually increase the key strength by reducing the effects of intersensor variability. Moreover, we find that the maximal key strength of a 60-bit key varies between 29.2 bits and only 5.7 bits, depending on the subject's HRV. To improve security, we introduce the inter-multi-pulse interval (ImPI), a novel method of extracting entropy from the heart by considering the time difference between nonconsecutive heart beats. Given the same authentication time, using the ImPI for key generation increases key strength by up to 3.4 × (+19.2 bits) for subjects with limited HRV, at the cost of an extended key-generation time of 4.8 × (+45 s).

  15. Peak misdetection in heart-beat-based security: Characterization and tolerance.

    Science.gov (United States)

    Seepers, Robert M; Strydis, Christos; Peris-Lopez, Pedro; Sourdis, Ioannis; De Zeeuw, Chris I

    2014-01-01

    The Inter-Pulse-Interval (IPI) of heart beats has previously been suggested for security in mobile health (mHealth) applications. In IPI-based security, secure communication is facilitated through a security key derived from the time difference between heart beats. However, there currently exists no work which considers the effect on security of imperfect heart-beat (peak) detection. This is a crucial aspect of IPI-based security and likely to happen in a real system. In this paper, we evaluate the effects of peak misdetection on the security performance of IPI-based security. It is shown that even with a high peak detection rate between 99.9% and 99.0%, a significant drop in security performance may be observed (between -70% and -303%) compared to having perfect peak detection. We show that authenticating using smaller keys yields both stronger keys as well as potentially faster authentication in case of imperfect heart beat detection. Finally, we present an algorithm which tolerates the effect of a single misdetected peak and increases the security performance by up to 155%.

  16. A new beating-heart off-pump coronary artery bypass grafting training model

    NARCIS (Netherlands)

    Bouma, Wobbe; Kuijpers, Michiel; Bijleveld, Aanke; De Maat, Gijs E.; Koene, Bart M.; Erasmus, Michiel E.; Natour, Ehsan; Mariani, Massimo A.

    OBJECTIVES: Training models are essential in mastering the skills required for off-pump coronary artery bypass grafting (OPCAB). We describe a new, high-fidelity, effective and reproducible beating-heart OPCAB training model in human cadavers. METHODS: Human cadavers were embalmed according to the

  17. Extracting fetal heart beats from maternal abdominal recordings: selection of the optimal principal components.

    Science.gov (United States)

    Di Maria, Costanzo; Liu, Chengyu; Zheng, Dingchang; Murray, Alan; Langley, Philip

    2014-08-01

    This study presents a systematic comparison of different approaches to the automated selection of the principal components (PC) which optimise the detection of maternal and fetal heart beats from non-invasive maternal abdominal recordings.A public database of 75 4-channel non-invasive maternal abdominal recordings was used for training the algorithm. Four methods were developed and assessed to determine the optimal PC: (1) power spectral distribution, (2) root mean square, (3) sample entropy, and (4) QRS template. The sensitivity of the performance of the algorithm to large-amplitude noise removal (by wavelet de-noising) and maternal beat cancellation methods were also assessed. The accuracy of maternal and fetal beat detection was assessed against reference annotations and quantified using the detection accuracy score F1 [2*PPV*Se / (PPV + Se)], sensitivity (Se), and positive predictive value (PPV). The best performing implementation was assessed on a test dataset of 100 recordings and the agreement between the computed and the reference fetal heart rate (fHR) and fetal RR (fRR) time series quantified.The best performance for detecting maternal beats (F1 99.3%, Se 99.0%, PPV 99.7%) was obtained when using the QRS template method to select the optimal maternal PC and applying wavelet de-noising. The best performance for detecting fetal beats (F1 89.8%, Se 89.3%, PPV 90.5%) was obtained when the optimal fetal PC was selected using the sample entropy method and utilising a fixed-length time window for the cancellation of the maternal beats. The performance on the test dataset was 142.7 beats(2)/min(2) for fHR and 19.9 ms for fRR, ranking respectively 14 and 17 (out of 29) when compared to the other algorithms presented at the Physionet Challenge 2013.

  18. Separation of Beating Cardiac Myocytes from Suspensions of Heart Cells

    Science.gov (United States)

    Pretlow, Thomas G.; Glick, Melvin R.; Reddy, William J.

    1972-01-01

    Heart cells were obtained in suspension after incubation with collagenase and hyaluronidase in Saline A. Cardiac myocytes were separated by isopycnic centrifugation in 88.6 to 92.4% purity from other heart cells with different densities, and by velocity or rate-zonal sedimentation, in 92.8 to 97.4% purity from heart cells with different diameters. A previously described computer integration of the differential sedimentation equation was used to determine the centrifugal force, duration of centrifugation and gradient design, which would permit the separation of cardiac myocytes from other heart cells by velocity sedimentation. The myocytes continued to contract rhythmically after being recovered from the density gradients. Velocity sedimentation was superior to isopycnic sedimentation for the separation of cardiac myocytes from heart cell suspensions because it gave the most highly purified myocytes, resulted in recovery of the largest proportion of myocytes in purified fractions from the gradient and required lower centrifugal forces for shorter periods of time. The potential significance of the availability of pure cardiac myocytes is discsused. ImagesFig 2Fig 1 PMID:4336547

  19. A Quadratic Nonlinear Prediction-Based Heart Motion Model following Control Algorithm in Robotic-Assisted Beating Heart Surgery

    Directory of Open Access Journals (Sweden)

    Fan Liang

    2013-01-01

    Full Text Available Off-pump coronary artery bypass graft surgery outperforms the traditional on-pump surgery because the assisted robotic tools can cancel the relative motion between the beating heart and the robotic tools, which reduces post-surgery complications for patients. The challenge for the robot assisted tool when tracking the beating heart is the abrupt change caused by the nonlinear nature of heart motion and high precision surgery requirements. A characteristic analysis of 3D heart motion data through bi-spectral analysis demonstrates the quadratic nonlinearity in heart motion. Therefore, it is necessary to introduce nonlinear heart motion prediction into the motion tracking control procedures. In this paper, the heart motion tracking problem is transformed into a heart motion model following problem by including the adaptive heart motion model into the controller. Moreover, the model following algorithm with the nonlinear heart motion model embedded inside provides more accurate future reference by the quadratic term of sinusoid series, which could enhance the tracking accuracy of sharp change point and approximate the motion with sufficient detail. The experiment results indicate that the proposed algorithm outperforms the linear prediction-based model following controller in terms of tracking accuracy (root mean square.

  20. Ultrasound based mitral valve annulus tracking for off-pump beating heart mitral valve repair

    Science.gov (United States)

    Li, Feng P.; Rajchl, Martin; Moore, John; Peters, Terry M.

    2014-03-01

    Mitral regurgitation (MR) occurs when the mitral valve cannot close properly during systole. The NeoChordtool aims to repair MR by implanting artificial chordae tendineae on flail leaflets inside the beating heart, without a cardiopulmonary bypass. Image guidance is crucial for such a procedure due to the lack of direct vision of the targets or instruments. While this procedure is currently guided solely by transesophageal echocardiography (TEE), our previous work has demonstrated that guidance safety and efficiency can be significantly improved by employing augmented virtuality to provide virtual presentation of mitral valve annulus (MVA) and tools integrated with real time ultrasound image data. However, real-time mitral annulus tracking remains a challenge. In this paper, we describe an image-based approach to rapidly track MVA points on 2D/biplane TEE images. This approach is composed of two components: an image-based phasing component identifying images at optimal cardiac phases for tracking, and a registration component updating the coordinates of MVA points. Preliminary validation has been performed on porcine data with an average difference between manually and automatically identified MVA points of 2.5mm. Using a parallelized implementation, this approach is able to track the mitral valve at up to 10 images per second.

  1. Robust feature tracking on the beating heart for a robotic-guided endoscope.

    Science.gov (United States)

    Elhawary, Haytham; Popovic, Aleksandra

    2011-12-01

    Visualization during minimally invasive bypass surgery on the beating heart can be enhanced by using a robotic-guided endoscope and visual servoing from the endoscopic images. In order to achieve these objectives, this work has focused on developing and testing algorithms for accurate, robust and real-time motion tracking of features on the beating heart, using marker-less approaches and an uncalibrated endoscope. Lucas-Kanade pyramidal optical flow-based algorithms and speeded-up robust features (SURF)-based methods have been extensively evaluated, using a range of developed metrics, in order to quantify accuracy, robustness and drift under a variety of circumstances. Three sets of experiments are reported: the first set compared the two tracking methods, using a beating-heart phantom and a static endoscope; the second set evaluated the methods when images were taken using a moving robotic-guided endoscope; and finally, the Lucas-Kanade optical flow algorithm was extensively tested in a visual servoing application, using a robotic endoscope. The combination of a Lucas-Kanade tracking algorithm and a SURF-based feature detection method gave the best performance in terms of accuracy and robustness of tracking, while preserving real-time computation requirements. The optimal parameters consist of a window size of 51 × 51 pixels and an interframe motion threshold of 20 pixels. Feature tracking was successfully integrated into uncalibrated visual servoing or a robotic-guided endoscope. Robust feature tracking on a beating heart with endoscopic video can be achieved in real-time and may facilitate robotically-assisted, minimally invasive bypass surgery and conventional laparoscopic surgery. Copyright © 2011 John Wiley & Sons, Ltd.

  2. Sudden cardiac death in dogs with remodeled hearts is associated with larger beat-to-beat variability of repolarization

    DEFF Research Database (Denmark)

    Thomsen, Morten Bækgaard; Truin, Michiel; van Opstal, Jurren M

    2005-01-01

    Increased proarrhythmia in dogs with chronic AV block (AVB) has been explained by ventricular remodeling causing a decrease in repolarization reserve. Beat-to-beat variability of repolarization (BVR) has been suggested to reflect repolarization reserve, in which high variability represents dimini...

  3. A new beating-heart off-pump coronary artery bypass grafting training model.

    Science.gov (United States)

    Bouma, Wobbe; Kuijpers, Michiel; Bijleveld, Aanke; De Maat, Gijs E; Koene, Bart M; Erasmus, Michiel E; Natour, Ehsan; Mariani, Massimo A

    2015-01-01

    Training models are essential in mastering the skills required for off-pump coronary artery bypass grafting (OPCAB). We describe a new, high-fidelity, effective and reproducible beating-heart OPCAB training model in human cadavers. Human cadavers were embalmed according to the 'Thiel method' which allows their long-term and repeated use. The training model was constructed by bilateral ligation of the pulmonary veins, cross-clamping of the aorta, positioning of an intra-aortic balloon pump (IABP) in the left ventricle (LV) through the apex (tightened with pledget-reinforced purse strings) and finally placing of a fluid line in the LV through the left atrial appendage (tightened with a pledget-reinforced purse string). The LV was filled with saline to the desired pressure through the fluid line and the IABP was switched on and set to a desired frequency [usually 60-80 beats per minute (bpm)]. A high-fidelity simulation has known limitations, but a more complex, realistic training environment with an actual beating (human) heart strengthens the entire training exercise and is of incremental value. All types of coronary artery anastomosis can be trained with this model. Training should be performed under the supervision of an experienced OPCAB surgeon and training progress is best evaluated with serial Objective Structured Assessment of Technical Skills (OSATS). A score of at least 48 points on the final OSATS ('good' on all components) is recommended before trainees can start their training on patients. The entire set-up provides a versatile training model to help develop and improve the skills required to safely perform beating heart OPCAB anastomoses. © The Author 2014. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.

  4. A mitral annulus tracking approach for navigation of off-pump beating heart mitral valve repair.

    Science.gov (United States)

    Li, Feng P; Rajchl, Martin; Moore, John; Peters, Terry M

    2015-01-01

    porcine data, the authors compared the tracked MVA to a manually segmented MVA. The overall accuracy is 2.37 ± 1.67 mm for single plane images and 2.35 ± 1.55 mm for biplane images. The interoperator variation in manual segmentation was 2.32 ± 1.24 mm for single plane images and 1.73 ± 1.18 mm for biplane images. The computational efficiency of the algorithm on a desktop computer with an Intel(®) Xeon(®) CPU @3.47 GHz and an NVIDIA GeForce 690 graphic card is such that the time required for registering four MVA points was about 60 ms. The authors developed a rapid MVA tracking algorithm for use in the guidance of off-pump beating heart transapical mitral valve repair. This approach uses 2D biplane TEE images and was tested on a dynamic heart phantom and interventional porcine image data. Results regarding the accuracy and efficiency of the authors' MVA tracking algorithm are promising, and fulfill the requirements for surgical navigation.

  5. Power Spectrum Analysis of Heart Rate Fluctuation: A Quantitative Probe of Beat-to-Beat Cardiovascular Control

    Science.gov (United States)

    1981-01-01

    renm-angMiemin system activity trrimgh f.uumliites the umpUtude of the speitrjl peak located at OM hertz. Our data iherefim provide evuleme that...fluctuations in peripheral vascular ccsist- ance resulting from the autoregulation of local blood flow in tissue beds. The sympathetic and parasympalhctic...maintain cardiovascular homeostasis by responding to beat-to-beat perturbations that are sensed by a variety of pressorc- ceplors and chemoreceptors . The

  6. Comparison of methods for editing of ectopic beats in measurements of short-term non-linear heart rate dynamics.

    Science.gov (United States)

    Tarkiainen, Tuula H; Kuusela, Tom A; Tahvanainen, Kari U O; Hartikainen, Juha E K; Tiittanen, Pekka; Timonen, Kirsi L; Vanninen, Esko J

    2007-03-01

    Non-linear heart rate (HR) dynamics characterizes the fractal properties and complexity of the variations in HR. Ventricular and supraventricular ectopic beats might introduce a mathematical artefact to the analyses on sinus rhythm. We therefore evaluated the effects of different editing practices for ectopic beats such that 753 40-min ECG recordings were (i) not edited for the ectopic beats, or the ectopic beats were edited with (ii) an interpolation or with (iii) a deletion method before the analyses of non-linear HR dynamics. The non-linear HR dynamics analyses included detrended fluctuation analysis (DFA), approximate entropy, symbolic dynamics (SymDyn), fractal dimension and return map (RM). We found that the short-term scaling exponent (alpha1) of DFA, forbidden words of SymDyn and RM were sensitive measurements to the ectopic beats and there were strong correlations between these measurements and the number of ectopic beats. In addition, the unedited ectopic beats significantly lowered the stability of these measurements. However, the editing either with interpolation or deletion method corrected the measurements for the bias caused by the ectopic beats. On the contrary, the entropy measurements were not as sensitive to the ectopic beats. In conclusion, the ectopic beats affect the non-linear HR dynamics of sinus rhythm differently, causing a more marked bias in fractal than in complexity measurements of non-linear HR dynamics. This erroneous effect of ectopic beats can be corrected with a proper editing of these measurements. Therefore, there is an obvious need for standardized editing practices for ectopic beats before the analysis of non-linear HR dynamics.

  7. What makes the heart of Boa constrictor (Squamata: Boidae beat faster?

    Directory of Open Access Journals (Sweden)

    João Fabrício Mota Rodrigues

    2015-02-01

    Full Text Available Body size is highly correlated with metabolism, which in turn influences physiological rates such as heart rate. In general, heart rate is negatively influenced by the size of animal's body, but there is insufficient data corroborating this pattern in snakes. This study evaluated how body size affects heart rate in captive Boa constrictor Linnaeus, 1758. We measured the heart rate of 30 snakes using digital palpation and evaluated how this rate is influenced by body mass and sex using Analysis of Covariance (ANCOVA. The heart rate of the snakes was 58.8 ± 6.7 bpm (beats per minute. Body size, estimated as log-transformed body mass, negatively influenced heart rate (F1,28 = 10.27, p = 0.003, slope = -0.00004, R2 = 0.27, but sex had no effect (F1,27 = 0.07, p = 0.80. In conclusion, this result corroborates the negative relationship between body size and heart rate for snakes and reinforces the influence of related metabolic characteristics, such as body size, on the physiological parameters of snakes.

  8. Experimental small bowel transplantation from non-heart-beating donors: a large-animal study.

    Science.gov (United States)

    Cobianchi, L; Zonta, S; Vigano, J; Dominioni, T; Ciccocioppo, R; Morbini, P; Bottazzi, A; Mazzilli, M; De Martino, M; Vicini, E; Filisetti, C; Botrugno, I; Dionigi, P; Alessiani, M

    2009-01-01

    The shortage of organs in the last 20 years is stimulating the development of new strategies to expand the pool of donors. The harvesting of a graft from non-heart-beating donors (NHBDs) has been successfully proposed for kidney and liver transplantation. To our knowledge, no studies are available for small bowel transplantation using NHBDs. In an experimental setting of small bowel transplantation, we studied the feasibility of using intestinal grafts retrieved from NHBDs. Twenty five Large White piglets underwent total orthotopic small bowel transplantation and were randomly divided as follow: NHBD group (n = 15) received grafts from NHBDs; heart-beating donor (HBD) group (n = 10) received grafts from HBDs. The NHBD pigs were sacrificed inducing the cardiac arrest by a lethal potassium injection. After 20 minutes (no touch period = warm ischemia), they underwent cardiac massage, laparotomy, and aorta cannulation for flushing and cooling the abdominal organs. In HBDs, the cardiac arrest was induced at the time of organ cold perfusion. In both groups, immunosuppression was based on tacrolimus oral monotherapy. The animals were observed for 30 days. The graft absorptive function was studied at day 30 using the D-xylose absorption test. Histological investigation included HE (Hematoxilin and Eosin) microscopical analysis and immunohistological staining. Animals in the NHBD group died due to infection (n = 3), acute cellular rejection (n = 2), technical complications (n = 2), and intestinal failure (n = 8). In the HBD group, all animals but two were alive at the end of the study. The D-xylose absorption was significantly lower among the NHBD compared with the HBD group (P mucosa is sensitive to ischemic injury. When the intestinal graft is harvested from NHBDs, the infectious-related mortality was higher and the absorptive function lower. Histological examination confirmed a higher grade of ischemic injury in the NHBD grafts that correlated with the clinical data

  9. Comparison of heart rate response to an epinephrine test dose and painful stimulus in children during sevoflurane anesthesia: heart rate variability and beat-to-beat analysis.

    Science.gov (United States)

    Wodey, Eric; Senhadji, Lotfi; Bansard, Jean Yves; Terrier, Anne; Carré, François; Ecoffey, Claude

    2003-01-01

    During regional anesthesia, various stimuli leading to an adrenergic response can occur. However, simulation of an epidural test dose by using intravenous administration of epinephrine (EPI) has always been compared with an intravenous saline infusion as the control. The aim of this study was to evaluate the possibility of distinguishing in children the effect on HR by an intravascular epinephrine infusion and a painful stimulus, using heart rate variability (HRV) and beat-to-beat analysis of HR. Thirty American Society of Anesthesiologists physical status P I children who required elective surgery were studied. At 1 minimum alveolar concentration (MAC) of sevoflurane, electrocardiogram was recorded continuously. Systolic blood pressure (SBP) was measured every minute. Measurements were performed after an intravenous administration of 0.5 microg/kg of epinephrine and during a small skin surgical incision (SI). Time-varying auto-regressive modeling of the interpolated RR sequences was performed for estimating power spectrum (msec(2)). The HF bands were defined by (0.15-0.4 Hz). Median (range) age and weight of all children were 3.5 (1-10) years and 16 (9-30) kg. EPI produced a lower increase in HR than did SI. SBP increased significantly more than did after SI. T-wave amplitude increased significantly after EPI but not after SI. Sixty seconds after the first change in HR, a secondary decrease (in comparison to control value) can be detected with EPI in contrast to SI. HF spectral power increased significantly after EPI administration but decreased after SI. The sensitivity, specificity, and positive and negative predictive value were respectively for DeltaHR >10 beats per minuteof 56%, 26%, 43%, and 38%; for DeltaSBP >15 mm Hg of 60%, 86%, 81%, and 67%; and for DeltaT-wave amplitude >25% of 86%, 73%, 76%, and 84%. Using detection of the secondary decrease of HR, 60 seconds after the first change in HR, sensitivity, specificity, and positive and a negative predictive

  10. Usefulness of one-stage coronary artery bypass grafting on the beating heart and abdominal aortic aneurysm repair.

    Science.gov (United States)

    Morimoto, Keisuke; Taniguchi, Iwao; Miyasaka, Shigeto; Aoki, Tetsuya; Kato, Ippei; Yamaga, Takeshi

    2004-02-01

    Abdominal aortic aneurysm (AAA) is commonly associated with coronary artery disease (CAD). Simultaneous coronary artery bypass grafting (CABG) with cardiopulmonary bypass (CPB) under cardiac arrest and AAA repair may be considerably invasive. Recently CABG under the beating heart without CPB has been reported as a less invasive method. We report the combined operation of CABG on a beating heart and AAA repair for AAA patients with CAD, and compare it with a separate operation. A retrospective review of the records of consecutive patients who underwent elective combined procedure or single operation for CABG on a beating heart and/or repair of the AAA between May 1999 and October 2001 was carried out. Ten patients underwent combined procedures. A single operation, CABG on a beating heart or repair of AAA, were performed in 27 or 19 patients. There were no significant differences with regard to intraoperative blood loss, transfusion and postoperative intubation time among the three groups. There was no operative mortality for any of the three groups. All cases were discharged without severe complications and with patent coronary bypass grafts. There was a decrease in mean total hospital costs for the combined operation group compared with the CABG group plus AAA repair group (3.34 million versus 5.87 million yen). Combined CABG on a beating heart and AAA repair on a one-step approach appears to be a safe and useful therapeutic strategy for AAA patients with CAD.

  11. Heart rate turbulence after ventricular premature beats in healthy Doberman pinschers and those with dilated cardiomyopathy.

    Science.gov (United States)

    Harris, J D; Little, C J L; Dennis, J M; Patteson, M W

    2017-10-01

    To describe the measurement of heart rate turbulence (HRT) after ventricular premature beats and compare HRT in healthy Doberman pinschers and those with dilated cardiomyopathy (DCM), with and without congestive heart failure (CHF). Sixty-five client-owned Dobermans: 20 healthy (NORMAL), 31 with preclinical DCM and 14 with DCM and CHF (DCM + CHF). A retrospective study of data retrieved from clinical records and ambulatory ECG (Holter) archives, including data collected previously for a large-scale prospective study of Dobermans with preclinical DCM. Holter data were reanalysed quantitatively, including conventional time-domain heart rate variability and the HRT parameters turbulence onset and turbulence slope. Heart rate turbulence could be measured in 58/65 dogs. Six Holter recordings had inadequate ventricular premature contractions (VPCs) and one exhibited VPCs too similar to sinus morphology. Heart rate turbulence parameter, turbulence onset, was significantly reduced in DCM dogs, whereas conventional heart rate variability measures were not. Heart rate variability and HRT markers were reduced in DCM + CHF dogs as expected. Heart rate turbulence can be measured from the majority of good quality standard canine 24-hour Holter recordings with >5 VPCs. Turbulence onset is significantly reduced in Dobermans with preclinical DCM which indicates vagal withdrawal early in the course of disease. Heart rate turbulence is a powerful prognostic indicator in human cardiac disease which can be measured from standard 24-hour ambulatory ECG (Holter) recordings using appropriate computer software. Further studies are warranted to assess whether HRT may be of prognostic value in dogs with preclinical DCM and in other canine cardiac disease. Copyright © 2017 Elsevier B.V. All rights reserved.

  12. Validation of four-dimensional ultrasound for targeting in minimally-invasive beating-heart surgery

    Science.gov (United States)

    Pace, Danielle F.; Wiles, Andrew D.; Moore, John; Wedlake, Chris; Gobbi, David G.; Peters, Terry M.

    2009-02-01

    Ultrasound is garnering significant interest as an imaging modality for surgical guidance, due to its affordability, real-time temporal resolution and ease of integration into the operating room. Minimally-invasive intracardiac surgery performed on the beating-heart prevents direct vision of the surgical target, and procedures such as mitral valve replacement and atrial septal defect closure would benefit from intraoperative ultrasound imaging. We propose that placing 4D ultrasound within an augmented reality environment, along with a patient-specific cardiac model and virtual representations of tracked surgical tools, will create a visually intuitive platform with sufficient image information to safely and accurately repair tissue within the beating heart. However, the quality of the imaging parameters, spatial calibration, temporal calibration and ECG-gating must be well characterized before any 4D ultrasound system can be used clinically to guide the treatment of moving structures. In this paper, we describe a comprehensive accuracy assessment framework that can be used to evaluate the performance of 4D ultrasound systems while imaging moving targets. We image a dynamic phantom that is comprised of a simple robot and a tracked phantom to which point-source, distance and spherical objects of known construction can be attached. We also follow our protocol to evaluate 4D ultrasound images generated in real-time by reconstructing ECG-gated 2D ultrasound images acquired from a tracked multiplanar transesophageal probe. Likewise, our evaluation framework allows any type of 4D ultrasound to be quantitatively assessed.

  13. Animal model for liver cell banking from non-heart beating donors after prolonged ischaemia time.

    Science.gov (United States)

    Porretti, L; Gatti, S; Gramignoli, R; Colombo, F; Lopa, R; Cattaneo, A; Scalamogna, M; Colombo, G; Rossi, G; Bonino, F; Rebulla, P; Prati, D

    2006-12-01

    Although there is a growing interest on the use of non-heart beating donors to enlarge the liver donor pool, livers with prolonged warm ischaemia time are not currently considered for organ transplantation. We hypothesised that these organs may represent a source of hepatocytes for cell transplantation and/or use in bioartificial liver devices. Thus, we investigated if prolonged ischaemia could influence the recovery and viability of functional hepatocytes dissociated from rat livers. Hepatocytes were isolated from the liver within 15 min after death (t=15 min) and after 4, 8 and 12h of ischaemia. Cells were either maintained in culture or cryopreserved. In all products, we evaluated cell recovery and viability, hepatocyte markers and cellular functions, including albumin and urea production. The number of cells per gram of tissue was similar at 15 min, 4 and 8h, while it was significantly decreased at 12h. About 0.2 x 10(6) viable cells expressing hepatocyte markers and producing albumin and urea were isolated up to 8h of ischaemia per gram of tissue. Recovery of viable and functional hepatocytes seems possible after prolonged ischaemia time. These data warrant the evaluation of hepatocyte isolation from human livers of non-heart beating donors.

  14. Surgical correction of ruptured aneurysms of the sinus of Valsalva using on-pump beating-heart technique

    Directory of Open Access Journals (Sweden)

    Lin Hui

    2010-05-01

    Full Text Available Abstract Background Rupture of aneurysms of the sinus of Valsalva results in abrupt onset of congestive heart failure. On-pump beating-heart surgery may reduce cardiac impairment by maintaining coronary blood flow and avoiding cardioplegia. Herein, we report the operative correction of thirty-one patients of ruptured aneurysms of the sinus of Valsalva, using the on-pump beating-heart technique. Methods Thirty-one patients with ruptured aneurysms of the sinus of Valsalva underwent operative corrections using the on-pump beating-heart technique. In patients with fistula diameter less than 1 cm and no aortic regurgitation, the aorta was unclamped throughout cardiopulmonary bypass(CPB while receiving antegrade heart perfusion. In remainder of patients, retrograde perfusion was used. Results After intracardiac manipulation was complete and the nasopharyngeal temperature was raised to 36-37°C, the patients were smoothly weaned off CPB. There were no early or late postoperative deaths. All patients were in New York Heart Association functional class I at follow-up (range, 0.5-1 year. Mild-to-moderate aortic valve regurgitation was observed in one patient. No recurrence of the left-to-right shunt from ruptured aneurysms of the sinus of Valsalva was observed. Conclusions Beating heart on pump allows adequate examination of the aortic lesion under near-physiologic conditions, allows decrease in ischemia-reperfusion injury and potentially decreases the risk of serious or fatal rhythm disturbances. On-pump beating-heart technique for repair of ruptured aneurysm of sinus of Valsalva is feasible and promising. Antegrade heart perfusion is suitable for patients with a fistula diameter

  15. Ultrasound functional imaging in an ex vivo beating porcine heart platform

    Science.gov (United States)

    Petterson, Niels J.; Fixsen, Louis S.; Rutten, Marcel C. M.; Pijls, Nico H. J.; van de Vosse, Frans N.; Lopata, Richard G. P.

    2017-12-01

    In recent years, novel ultrasound functional imaging (UFI) techniques have been introduced to assess cardiac function by measuring, e.g. cardiac output (CO) and/or myocardial strain. Verification and reproducibility assessment in a realistic setting remain major issues. Simulations and phantoms are often unrealistic, whereas in vivo measurements often lack crucial hemodynamic parameters or ground truth data, or suffer from the large physiological and clinical variation between patients when attempting clinical validation. Controlled validation in certain pathologies is cumbersome and often requires the use of lab animals. In this study, an isolated beating pig heart setup was adapted and used for performance assessment of UFI techniques such as volume assessment and ultrasound strain imaging. The potential of performing verification and reproducibility studies was demonstrated. For proof-of-principle, validation of UFI in pathological hearts was examined. Ex vivo porcine hearts (n  =  6, slaughterhouse waste) were resuscitated and attached to a mock circulatory system. Radio frequency ultrasound data of the left ventricle were acquired in five short axis views and one long axis view. Based on these slices, the CO was measured, where verification was performed using flow sensor measurements in the aorta. Strain imaging was performed providing radial, circumferential and longitudinal strain to assess reproducibility and inter-subject variability under steady conditions. Finally, strains in healthy hearts were compared to a heart with an implanted left ventricular assist device, simulating a failing, supported heart. Good agreement between ultrasound and flow sensor based CO measurements was found. Strains were highly reproducible (intraclass correlation coefficients  >0.8). Differences were found due to biological variation and condition of the hearts. Strain magnitude and patterns in the assisted heart were available for different pump action, revealing

  16. Effect of Missing Inter-Beat Interval Data on Heart Rate Variability Analysis Using Wrist-Worn Wearables.

    Science.gov (United States)

    Baek, Hyun Jae; Shin, JaeWook

    2017-08-15

    Most of the wrist-worn devices on the market provide a continuous heart rate measurement function using photoplethysmography, but have not yet provided a function to measure the continuous heart rate variability (HRV) using beat-to-beat pulse interval. The reason for such is the difficulty of measuring a continuous pulse interval during movement using a wearable device because of the nature of photoplethysmography, which is susceptible to motion noise. This study investigated the effect of missing heart beat interval data on the HRV analysis in cases where pulse interval cannot be measured because of movement noise. First, we performed simulations by randomly removing data from the RR interval of the electrocardiogram measured from 39 subjects and observed the changes of the relative and normalized errors for the HRV parameters according to the total length of the missing heart beat interval data. Second, we measured the pulse interval from 20 subjects using a wrist-worn device for 24 h and observed the error value for the missing pulse interval data caused by the movement during actual daily life. The experimental results showed that mean NN and RMSSD were the most robust for the missing heart beat interval data among all the parameters in the time and frequency domains. Most of the pulse interval data could not be obtained during daily life. In other words, the sample number was too small for spectral analysis because of the long missing duration. Therefore, the frequency domain parameters often could not be calculated, except for the sleep state with little motion. The errors of the HRV parameters were proportional to the missing data duration in the presence of missing heart beat interval data. Based on the results of this study, the maximum missing duration for acceptable errors for each parameter is recommended for use when the HRV analysis is performed on a wrist-worn device.

  17. [Coronary artery bypass grafting on the beating heart in high-risk patients].

    Science.gov (United States)

    Rastan, Ardawan Julian; Walther, Thomas; Falk, Volkmar; Lehmann, Sven; Kempfert, Jörg; Mohr, Friedrich Wilhelm

    2007-09-01

    Since the introduction of off-pump coronary artery bypass grafting (OPCAB) for coronary multivessel disease there was growing interest to evaluate the impact of OPCAB surgery compared to conventional coronary artery bypass grafting (CCAB) with cardiopulmonary bypass and cardioplegic arrest. However, subsequent prospective randomized studies and meta-analyses comparing OPCAB and CCAB surgery were performed on low-risk patients or mixed-risk populations. They usually failed to demonstrate a significant benefit of OPCAB surgery on early mortality or perioperative major cardiac and cerebrovascular events. In recent years, efforts were made to analyze the meaning of beating-heart concepts for patients with specific cardiac and extracardiac risks like ischemic cardiomyopathy, older age, renal failure, acute coronary syndrome, left main stenosis and others. For these subsets of patients several mono- and multicenter studies are available today. Even if most of them were nonrandomized and thus failed to reach evidence level A according to the AHA/ACC (American Heart Association/American College of Cardiology) definition, they still allow analyzing interim results for each specific perioperative risk factor. Particularly multi-risk patients and patients with severely reduced left ventricular function seem to benefit in terms of perioperative mortality and major morbidity by avoiding cardiopulmonary bypass and cardioplegic arrest. Analyzing early results and long-term follow-up of 364 patients with severely reduced ejection fractioncardiac ischemia and maintaining native coronary blood flow. Follow-up results were comparable for these patients. In conclusion, beating-heart coronary artery bypass grafting seems to be advantageous in various risk populations and should be considered for patients with more than average risks for cardiopulmonary bypass and cardioplegic arrest.

  18. Endovascular aortic aneurysm repair via the left ventricular apex of a beating heart.

    Science.gov (United States)

    MacDonald, Shaun; Cheung, Anson; Sidhu, Ravindar; Rheaume, Pascal; Grenon, S Marlene; Clement, Jason

    2009-03-01

    An elderly man presented with a ruptured aortic arch, left lung compression, and hemoptysis. Multiple comorbidities and inadequate aortoiliac access disqualified him from conventional open repair or hybrid retrograde transarterial thoracic endovascular aortic repair (TEVAR). Because our center has recently reported that a thoracic aortic endograft can be successfully placed through the apex of the LV of a beating heart in a pig model, we received approval for the compassionate use of antegrade transapical TEVAR (TaTEVAR) with bilateral femoral-carotid revascularization to repair the aortic arch. As in our animal model, TaTEVAR was performed with accuracy and minimal hemodynamic compromise. The patient was quickly weaned from inotropic and respiratory support postoperatively and was neurologically intact, but died on the tenth postoperative day from respiratory failure.

  19. Tracking and characterization of fragments in a beating heart using 3D ultrasound for interventional guidance.

    Science.gov (United States)

    Thienphrapa, Paul; Elhawary, Haytham; Ramachandran, Bharat; Stanton, Douglas; Popovic, Aleksandra

    2011-01-01

    Fragments generated by explosions and similar incidents can become trapped in a patient's heart chambers, potentially causing disruption of cardiac function. The conventional approach to removing such foreign bodies is through open heart surgery, which comes with high perioperative risk and long recovery times. We thus advocate a minimally invasive surgical approach through the use of 3D transesophageal echocardiography (TEE) and a flexible robotic end effector. In a phantom study, we use 3D TEE to track a foreign body in a beating heart, and propose a modified normalized cross-correlation method for improved accuracy and robustness of the tracking, with mean RMS errors of 2.3 mm. Motion analysis of the foreign body trajectory indicates very high speeds and accelerations, which render unfeasible a robotic retrieval method based on following the tracked trajectory. Instead, a probability map of the locus of the foreign body shows that the fragment tends to occupy only a small sub-volume of the ventricle, suggesting a retrieval strategy based on moving the robot end effector to the position with the highest spatial probability in order to maximize the possibility of capture.

  20. RF communication with implantable wireless device: effects of beating heart on performance of miniature antenna.

    Science.gov (United States)

    Murphy, Olive H; Borghi, Alessandro; Bahmanyar, Mohammad Reza; McLeod, Christopher N; Navaratnarajah, Manoraj; Yacoub, Magdi; Toumazou, Christofer

    2014-06-01

    The frequency response of an implantable antenna is key to the performance of a wireless implantable sensor. If the antenna detunes significantly, there are substantial power losses resulting in loss of accuracy. One reason for detuning is because of a change in the surrounding environment of an antenna. The pulsating anatomy of the human heart constitutes such a changing environment, so detuning is expected but this has not been quantified dynamically before. Four miniature implantable antennas are presented (two different geometries) along with which are placed within the heart of living swine the dynamic reflection coefficients. These antennas are designed to operate in the short range devices frequency band (863-870 MHz) and are compatible with a deeply implanted cardiovascular pressure sensor. The measurements recorded over 27 seconds capture the effects of the beating heart on the frequency tuning of the implantable antennas. When looked at in the time domain, these effects are clearly physiological and a combination of numerical study and posthumous autopsy proves this to be the case, while retrospective simulation confirms this hypothesis. The impact of pulsating anatomy on antenna design and the need for wideband implantable antennas is highlighted.

  1. Wash-out of the non-heart-beating donor liver: A comparison between ringer lactate, HTK, and polysol

    NARCIS (Netherlands)

    Bessems, M.; Doorschodt, B. M.; Albers, P. S.; van Vliet, A. K.; van Gulik, T. M.

    2005-01-01

    The solution of choice for wash-out of non-heart-beating donor (NHBD) livers is histidine tryptophan ketoglutarate (HTK). This solution has a lower viscosity, due to absence of a colloid, and is less expensive as compared to the University of Wisconsin (UW) solution. A new preservation solution for

  2. Operative correction of judoists’ training loads on the base of on-line monitoring of heart beats rate

    Directory of Open Access Journals (Sweden)

    Liu Yong Qiang

    2015-02-01

    Full Text Available Purpose: ensure increase of effectiveness of training process’s control by means of operative correction of training loads of different qualification judo wrestlers’ heart beats rate indicators. Material: the research was conducted on the base of Brest SCJSOR № 1. Judo wrestlers of different sport qualification (age 17-19 years old, n=15 participated in the research. Monitoring of judo wrestlers’ heart beats rate was carried out with the help of system “Polar”. Results: we have found factorial structure of functional fitness in every profile of sportsmen. Model characteristics of judo wrestlers were supplemented with the most important sides of functional fitness. Analysis of indicators of restoration effectiveness indicators (REI in both groups of judo wrestlers showed high level of organism’s responsiveness to training load of special and power orientation in comparison with speed power load. We have worked out algorithm of operative correction of training loads by indicators of heart beats rate in training process, depending on orientation and intensity of loads’ physiological influence on judo wrestler. Conclusions: Telemetric on-line monitoring of sportsman’s heart beats rate and calculation of REI permit to objectively assess effectiveness of training’s construction and of micro-cycle in total and detect in due time the trend to development of over-loading and failure of adaptation.

  3. An efficient method of addressing ectopic beats: new insight into data preprocessing of heart rate variability analysis*

    Science.gov (United States)

    Wen, Feng; He, Fang-tian

    2011-01-01

    Heart rate variability (HRV) analysis is affected by ectopic beats. An efficient method was proposed to deal with the ectopic beats. The method was based on trend correlation of the heart timing signal. Predictor of R-R interval (RRI) value at ectopic beat time was constructed by the weight calculation and the slope estimation of preceding normal RRI. The type of ectopic beat was detected and replaced by the predictor of RRI. The performance of the simulated signal after ectopic correction was tested by the standard value using power spectrum density (PSD) estimation, whereas the results of clinical data with ectopic beats were compared with the adjacent ectopic-free data. The result showed the frequency indexes after ectopy corrected had less error than other methods with the test of simulated signal and clinical data. It indicated our method could improve the PSD estimation in HRV analysis. The method had advantages of high accuracy and real time properties to recover the sinus node modulation. PMID:22135146

  4. An efficient method of addressing ectopic beats: new insight into data preprocessing of heart rate variability analysis.

    Science.gov (United States)

    Wen, Feng; He, Fang-Tian

    2011-12-01

    Heart rate variability (HRV) analysis is affected by ectopic beats. An efficient method was proposed to deal with the ectopic beats. The method was based on trend correlation of the heart timing signal. Predictor of R-R interval (RRI) value at ectopic beat time was constructed by the weight calculation and the slope estimation of preceding normal RRI. The type of ectopic beat was detected and replaced by the predictor of RRI. The performance of the simulated signal after ectopic correction was tested by the standard value using power spectrum density (PSD) estimation, whereas the results of clinical data with ectopic beats were compared with the adjacent ectopic-free data. The result showed the frequency indexes after ectopy corrected had less error than other methods with the test of simulated signal and clinical data. It indicated our method could improve the PSD estimation in HRV analysis. The method had advantages of high accuracy and real time properties to recover the sinus node modulation.

  5. Quality metrics for high order meshes: analysis of the mechanical simulation of the heart beat.

    Science.gov (United States)

    Lamata, Pablo; Roy, Ishani; Blazevic, Bojan; Crozier, Andrew; Land, Sander; Niederer, Steven A; Hose, D Rod; Smith, Nicolas P

    2013-01-01

    The quality of a computational mesh is an important characteristic for stable and accurate simulations. Quality depends on the regularity of the initial mesh, and in mechanical simulations it evolves in time, with deformations causing changes in volume and distortion of mesh elements. Mesh quality metrics are therefore relevant for both mesh personalization and the monitoring of the simulation process. This work evaluates the significance, in meshes with high order interpolation, of four quality metrics described in the literature, applying them to analyse the stability of the simulation of the heart beat. It also investigates how image registration and mesh warping parameters affect the quality and stability of meshes. Jacobian-based metrics outperformed or matched the results of coarse geometrical metrics of aspect ratio or orthogonality, although they are more expensive computationally. The stability of simulations of a complete heart cycle was best predicted with a specificity of 61%, sensitivity of 85%, and only nominal differences were found changing the intra-element and per-element combination of quality values. A compromise between fitting accuracy and mesh stability and quality was found. Generic geometrical quality metrics have a limited success predicting stability, and an analysis of the simulation problem may be required for an optimal definition of quality.

  6. Simulation of the Beating Heart Based on Physically Modeling aDeformable Balloon

    Energy Technology Data Exchange (ETDEWEB)

    Rohmer, Damien; Sitek, Arkadiusz; Gullberg, Grant T.

    2006-07-18

    The motion of the beating heart is complex and createsartifacts in SPECT and x-ray CT images. Phantoms such as the JaszczakDynamic Cardiac Phantom are used to simulate cardiac motion forevaluationof acquisition and data processing protocols used for cardiacimaging. Two concentric elastic membranes filled with water are connectedto tubing and pump apparatus for creating fluid flow in and out of theinner volume to simulate motion of the heart. In the present report, themovement of two concentric balloons is solved numerically in order tocreate a computer simulation of the motion of the moving membranes in theJaszczak Dynamic Cardiac Phantom. A system of differential equations,based on the physical properties, determine the motion. Two methods aretested for solving the system of differential equations. The results ofboth methods are similar providing a final shape that does not convergeto a trivial circular profile. Finally,a tomographic imaging simulationis performed by acquiring static projections of the moving shape andreconstructing the result to observe motion artifacts. Two cases aretaken into account: in one case each projection angle is sampled for ashort time interval and the other case is sampled for a longer timeinterval. The longer sampling acquisition shows a clear improvement indecreasing the tomographic streaking artifacts.

  7. A novel one-shot circular stapler closure for atrial septal defect in a beating-heart porcine model.

    Science.gov (United States)

    Tarui, Tatsuya; Tomita, Shigeyuki; Ishikawa, Norihiko; Ohtake, Hiroshi; Watanabe, Go

    2015-02-01

    In surgical atrial septal defect (ASD) closure, there are no techniques or devices that can close the ASD accurately in a short time under a beating heart. We have developed a simple and automatic ASD closure technique using a circular stapler. This study assessed the feasibility and efficacy of a new circular stapler closure for ASD. Under a continuous beating heart, hand-sewn patch plasty ASD closure was performed in 6 pigs (group A) and circular stapler ASD closure was performed in 6 pigs (group B). The time to close the ASD and the effectiveness of the closure were compared. Closure was significantly faster in group B (10.5 ± 1.0 seconds) than in group A (664 ± 10 seconds; p heart porcine model. Copyright © 2015 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.

  8. Arrhythmia risk assessment using heart rate variability parameters in patients with frequent ventricular ectopic beats without structural heart disease.

    Science.gov (United States)

    Barutçu, Ahmet; Temiz, Ahmet; Bekler, Adem; Altun, Burak; Kirilmaz, Bahadir; Aksu, Feyza Ulusoy; Küçük, Uğur; Gazi, Emine

    2014-11-01

    Ventricular ectopic beats (VEBs) are usually considered a benign condition that can be managed with conservative measures. Heart rate variability (HRV), which is one of the most important methods for assessing autonomic activity, is a noninvasive, quantitative method of analyzing autonomic effects on the heart. We aimed to investigate the risk of arrhythmia in patients with VEBs and without cardiovascular disease by using HRV parameters. Patients with frequent VEBs (more than 30 times in 1 hour, according to the Lown classification) were identified. Identified patients were evaluated by 24-hour ECG recording. Our study included 43 patients with frequent VEBs and 43 controls. General characteristics of the study population were similar. The LF (low frequency)/HF (high frequency) ratio was significantly higher in the frequent VEBs group than in the control group (P < 0.001). The rate of paroxysmal atrial fibrillation (PAF) was higher in the frequent VEB group than in the control group (P = 0.003). The number of VEBs was correlated with LF/HF ratio and PAF (r = 0.339, P = 0.001 and r = 0.294, P = 0.006, respectively). Our study showed that the sympathetic nervous system is dominant in young patients with VEBs and without significant comorbidities. There is a higher risk of atrial fibrillation in patients with VEBs and they should be monitored closely for atrial fibrillation. ©2014 Wiley Periodicals, Inc.

  9. Clinical and ultramicroscopic myocardial randomized study of beating versus arrested heart for mitral surgery

    National Research Council Canada - National Science Library

    Clotario Neptali Carrasco Cueva; Maiara dosSantos Rocha; Carlos Mauricio Cardeal Mendes; Luiz Antonio Rodrigues deFreitas; Jose Augusto Baucia; Roberto Badaro

    2013-01-01

    ...: This study compared clinical and transmission electron microscopic aspects of myocardial protection during mitral valve replacement using warm retrograde perfusion in empty beating versus arrested...

  10. [Flowmetric assessment of coronary bypass grafts in the conditions of artificial circulation and on the beating heart].

    Science.gov (United States)

    Bazylev, V V; Nemchenko, E V; Karnakhin, V A; Pavlov, A A; Mikulyak, A I

    2016-01-01

    Advantages and shortcomings of aortocoronary bypass grafting on the beating heart and in the conditions of artificial circulation (AC) have long been discussed. The data on patency of bypass grafts in the remote period are indicative of comparable results of operations with and without AC or advantages of using AC. In order to determine benefits of each method it is necessary to reveal intraoperative predictors of bypass grafts occlusion in the remote period. We analyzed the results of ultrasound flowmetry of the blood flow through the left internal thoracic artery during bypass grafting of the anterior descending artery with the use of AC and on the beating heart. A retrospective study included a total of 352 patients subdivided into 2 groups: Group One was composed of 120 patients undergoing surgery in the conditions of AC and Group Two comprised 232 patients subjected to similar operations on the beating heart. Blood flow was measured with the help of flowmeter VeryQ MediStim® after termination of AC and inactivation of heparin by protamine, with systolic pressure of 100-110 mm Hg. There were no statistically significant differences between the groups by the diameter and degree of stenosis of the anterior descending artery, diameter of the left internal thoracic artery. The mean volumetric blood flow velocity (Qmean) along the shunts in Group One was higher (p=0.01). No statistically significant differences by the pulsatility index (PI) between the groups were revealed (p=0.2). A conclusion was drawn that coronary bypass grafting of the anterior descending artery by the left internal thoracic artery in the conditions of artificial circulation made it possible to achieve higher volumetric velocity of blood flow through the conduit as compared with operations on the beating heart, with similar resistance index. The immediate results of the operations with the use of the both techniques did not differ.

  11. Heart beats rate indicators and structure of elite football referees’ and their assistants’ motor functioning in competition period

    Directory of Open Access Journals (Sweden)

    Chopilko T. G.

    2015-11-01

    Full Text Available Purpose: to analyze structure of motor functioning and heart beats rate indicators in elite football referees’ and their assistants’ competition activity. Material: in the research 15 referees and referees’ assistants of Ukrainian Prime League, 30 referees and referees’ assistants of first and second professional leagues of Ukraine participated. Observations over referees’ movements in 21 professional matches of Ukrainian professional leagues were fulfilled. Distance, passed by a referee in one match was determined. Results: It was found that during one match referee (depending on his functions - referee or referee’s assistant passes distance from 6000 to 12 000 meters. This scope of motor functioning depends also on motor activity of players and qualification level of teams-participants in the match. Motor actions of referees’ assistants change every 5 seconds during a match. During one match referee’s assistants fulfill about 20 sprints and 74 accelerations. A high temp of match total distance makes 1.2 km. Conclusions: Referees’ and referee assistants’ motor functioning and heart beats rate indicators can vary from aerobic-restoration to anaerobic-glycolytic zone. This fact shall be considered when planning program on special physical training. It should be noted that with heart beats rate of more than 180 bpm concentration of attention significantly weakens as well as ability to take prompt and correct decisions. In such cases probability of mistakes significantly increases.

  12. Comparison of three methods for beat-to-beat-interval extraction from continuous blood pressure and electrocardiogram with respect to heart rate variability analysis.

    Science.gov (United States)

    Suhrbier, Alexander; Heringer, Rafael; Walther, Thomas; Malberg, Hagen; Wessel, Niels

    2006-07-01

    In recent years the analysis of heart rate variability (HRV) has become a suitable method for characterizing autonomous cardiovascular regulation. The aim of this study was to investigate the differences in HRV estimated from continuous blood pressure (BP) measurement by different methods in comparison to electrocardiogram (ECG) signals. The beat-to-beat intervals (BBI) were simultaneously extracted from the ECG and blood pressure of 9 cardiac patients (10 min, Colin system, 1000-Hz sampling frequency). For both data types, slope, peak, and correlation detection algorithms were applied. The short-term variability was calculated using concurrent 10-min BP and ECG segments. The root mean square errors in comparison to ECG slope detection were: 1.74 ms for ECG correlation detection; 5.42 ms for ECG peak detection; 5.45 ms for BP slope detection; 5.75 ms for BP correlation detection; and 11.96 ms for BP peak detection. Our results show that the variability obtained with ECG is the most reliable. Moreover, slope detection is superior to peak detection and slightly superior to correlation detection. In particular, for ECG signals with higher frequency characteristics, peak detection often exhibits more artificial variability. Besides measurement noise, respiratory modulation and pulse transit time play an important role in determining BBI. The slope detection method applied to ECG should be preferred, because it is more robust as regards morphological changes in the signals, as well as physiological properties. As the ECG is not recorded in most animal studies, distal pulse wave measurement in combination with correlation or slope detection may be considered an acceptable alternative.

  13. Beating heart axillocoronary bypass for management of the untouchable ascending aorta in coronary artery bypass grafting.

    Science.gov (United States)

    Bonatti, J; Hangler, H; Oturanlar, D; Posch, L; Müller, L C; Voelckel, W; Schwarz, B; Bodner, G

    1999-11-01

    Cannulation and clamping of a severely atherosclerotic ascending aorta during coronary artery bypass grafting (CABG) can lead to cerebral embolization of atheromatous debris and should therefore be avoided whenever possible. A variety of surgical techniques including performance of extraanatomical coronary bypass conduits has been described to solve this problem. We report on a preliminary series of four patients in whom the axillary artery was used as an inflow vessel for venous coronary artery bypass grafts which were performed on the beating heart in order to achieve an aortic no touch concept. The axillary artery was exposed between the pectoralis major muscle and the deltoid muscle via an infraclavicular incision. A saphenous vein graft of at least 40 cm in length was sutured to the axillary artery and then brought into the pericardial cavity following an intercostal and transpleural route. The graft was anastomosed to the target vessel using local coronary occlusion. The procedure was carried out via sternotomy in three patients who also received additional internal mammary artery in situ grafts for adequate coronary revascularization. In one high risk patient an isolated axillocoronary bypass was performed in a minimally invasive fashion via anterolateral minithoracotomy. The procedure was completed without major technical difficulties in all four patients. The mean graft length required was 33.2 +/- 1.6 cm, postoperative ultrasonic duplex scans of the axillocoronary grafts revealed a mean flow of 62.5 +/- 23.6 ml/min. No stroke or brachial plexus injury occurred. Three patients are in angina class I (Canadian Cardiovascular Society Classification), one patient is in class II postoperatively. After a mean follow-up of 11.5 +/- 6.6 months postoperatively all grafts remain patent. Axillocoronary bypass grafting can be easily performed for management of the untouchable ascending aorta. Straightforward surgical technique and the accessibility to noninvasive

  14. Development of a non-heart-beating donor program and results after the first year.

    Science.gov (United States)

    Meneses, J C; Gámez, P; Mariscal, A; Marrón, C; Díaz-Hellín, V; Cortes, M; de Pablo, A; Lopez, E; Perez, V; Gonzalez, O; Juarros, L; Martinez, I; Hermoso, F; Avila, R; Zuluaga, M; de Nicolás, J L M

    2012-09-01

    Our lung transplant unit began activity in October 2008. We have performed 37 lung transplants with a hospital mortality of 2.7% (n = 1). The need for a greater number of donors and the presence of an already existent non-heart-beating donor (NHBD) program for abdominal grafts and tissues encouraged us to consider assessing lung grafts from these donors. It was necessary to develop a new multiorgan preservation methodology, "bithermia preservation." The clinical experience with which during the first year June 2010 to July 2011, including 15 NHBDs is presented herein. The chest x-ray was normal in 6 donors (40%) and 7 had pulmonary infiltrates. Bronchoscopy was normal in 8 donors (53%) but 3 had abundant bleeding airway secretions and signs of bronchoaspiration. Preservation procedures were performed in 6 donors. Pulmonary functional evaluation in 4 donors showed gas measurements to be adequate in 75% of cases. Three double-lung grafts were judged to be valid for implantation, among which we performed 3 lung transplantations, 1 bilateral and 2 unilaterals, while 2 grafts were offered to the National Transplant Organization for other units. No transplant suffered primary graft dysfunction; all 3 showed excellent function allowing early extubation in 2 cases. There was no in-hospital mortality. All 3 patients are alive and leading normal lives; none has bronchiolitis obliterans syndrome. In conclusion, the "bithermia preservation" methodology achieved adequate lung preservation in NHBDs, allowing liver, kidneys, and lungs to be obtained from the same donor. Copyright © 2012 Elsevier Inc. All rights reserved.

  15. Augmented reality image guidance improves navigation for beating heart mitral valve repair.

    Science.gov (United States)

    Chu, Michael W A; Moore, John; Peters, Terry; Bainbridge, Daniel; McCarty, David; Guiraudon, Gerard M; Wedlake, Chris; Lang, Pencilla; Rajchl, Martin; Currie, Maria E; Daly, Richard C; Kiaii, Bob

    2012-01-01

    Emerging off-pump beating heart valve repair techniques offer patients less invasive alternatives for mitral valve (MV) repair. However, most of these techniques rely on the limited spatial and temporal resolution of transesophageal echocardiography (TEE) alone, which can make tool visualization and guidance challenging. Using a magnetic tracking system and integrated sensors, we created an augmented reality (AR) environment displaying virtual representations of important intracardiac landmarks registered to biplane TEE imaging. In a porcine model, we evaluated the AR guidance system versus TEE alone using the transapically delivered NeoChord DS1000 system to perform MV repair with chordal reconstruction. Successful tool navigation from left ventricular apex to MV leaflet was achieved in 12 of 12 and 9 of 12 (P = 0.2) attempts with AR imaging and TEE alone, respectively. The distance errors of the tracked tool tip from the intended midline trajectory (5.2 ± 2.4 mm vs 16.8 ± 10.9 mm, P = 0.003), navigation times (16.7 ± 8.0 seconds vs 92.0 ± 84.5 seconds, P = 0.004), and total path lengths (225.2 ± 120.3 mm vs 1128.9 ± 931.1 mm, P = 0.003) were significantly shorter in the AR-guided trials compared with navigation with TEE alone. Furthermore, the potential for injury to other intracardiac structures was nearly 40-fold lower when using the AR imaging for tool navigation. The AR guidance also seemed to shorten the learning curve for novice surgeons. Augmented reality-enhanced TEE facilitates more direct and safe intracardiac navigation of the NeoChord DS tool from left ventricular apex to MV leaflet. Tracked tool path results demonstrate fourfold improved accuracy, fivefold shorter navigation times, and overall improved safety with AR imaging guidance.

  16. Extracorporeal membrane oxygenation support of donor abdominal organs in non-heart-beating donors.

    Science.gov (United States)

    Ko, W J; Chen, Y S; Tsai, P R; Lee, P H

    2000-04-01

    Both family consent and legal consent were required for organ/tissue donation from non-heart-beating donors (NHBD) in Taiwan. A district attorney had to come to the bedside to confirm the donor's asystole, confirm the family consent, and complete some legal documents before a legal consent was issued for organ donation. The resultant warm ischemic time would be unpredictably long and in fact precluded the organ donation from NHBD in Taiwan. We developed a method of using extracorporeal membrane oxygenation (ECMO) to maintain NHBD for a longer time and prevent warm ischemic injury of the donor abdominal organs. After ventilator disconnection in NHBD, phentolamine and heparin were injected and mannitol infusion was given. After the donor's asystole was confirmed by the electrocardiogram (EKG) strip recording, the ECMO support was set up through the right femoral veno-arterial route, an occlusion balloon catheter was inserted through the left femoral artery to occlude the thoracic aorta, and bilateral femoral arteries were ligated. Usually, the ECMO could begin within 10 min after the donor's asystole. The ECMO, combined with a cooler, provided cold oxygenated blood to the abdominal visceral organs, and prevented their warm ischemic injuries. Under the ECMO support (range: 45-70 min), eight renal grafts were procured from 4 NHBD. With the exception of the first two renal grafts with delayed function, all others had immediate function postoperatively and dialysis was no longer needed. In conclusion, by our ECMO technique, NHBD could be maintained for a longer time and the renal grafts had better immediate postoperative function than those reported by other methods.

  17. On-pump beating heart coronary surgery for high risk patients requiring emergency multiple coronary artery bypass grafting

    Directory of Open Access Journals (Sweden)

    von Segesser Ludwig K

    2008-07-01

    Full Text Available Abstract Background Cardiopulmonary bypass (CPB with aortic cross-clamping and cardioplegic arrest remains the method of choice for patients requiring standard myocardial revascularization. Therefore, very high-risk patients presenting with acute coronary syndrome, unstable angina, onset of cardiac decompensation and requiring emergency multiple myocardial revascularization, can have a poor outcome. The on-pump beating heart technique can reduce the mortality and the morbidity in such a selected group of patients and this report describes our clinical experience. Methods Out of 290 patients operated for CABG from January 2005 to January 2006, 25 (8.6% selected high-risk patients suffering from life threatening coronary syndrome (mean age 69 ± 7 years and requiring emergency multiple myocardial revascularization, underwent on-pump beating heart surgery. The mean pre-operative left ventricle ejection fraction (LVEF was 27 ± 8%. The majority of them (88% suffered of tri-vessel coronary disease and 6 (24% had a left main stump disease. Nine patients (35% were on severe cardiac failure and seven among them (28% received a pre-operative intra-aortic balloon pump. The pre-operative EuroScore rate was equal or above 8 in 18 patients (73%. Results All patients underwent on-pump-beating heart coronary revascularization. The mean number of graft/patient was 2.9 ± 0.6 and the internal mammary artery was used in 23 patients (92%. The mean CPB time was 84 ± 19 minutes. Two patients died during the recovery stay in the intensive care unit, and there were no postoperative myocardial infarctions between the survivors. Eight patients suffered of transitorily renal failure and 1 patient developed a sternal wound infection. The mean hospital stay was 12 ± 7 days. The follow-up was complete for all 23 patients survived at surgery and the mean follow-up time was 14 ± 5 months. One patient died during the follow-up for cardiac arrest and 2 patients required an

  18. NIR spectroscopic imaging to map hemoglobin + myoglobin oxygenation, their concentration and optical pathlength across a beating pig heart during surgery.

    Science.gov (United States)

    Gussakovsky, Eugene; Yang, Yanmin; Rendell, John; Jilkina, Olga; Kupriyanov, Valery

    2012-02-01

    The purpose of this paper is to demonstrate that near-infrared (NIR) spectroscopic imaging can provide spatial distribution (maps) of the absolute concentration of hemoglobin + myoglobin, oxygen saturation parameter and optical pathlength, reporting on the biochemico-physiological status of a beating heart in vivo. The method is based on processing the NIR spectroscopic images employing a first-derivative approach. Blood-pressure-controlled gating compensated the effect of heart motion on the imaging. All the maps are available simultaneously and noninvasively at a spatial resolution in the submillimeter range and can be obtained in a couple of minutes. The equipment has no mechanical contact with the tissue, thereby leaving the heart unaffected during the measurement. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  19. Preservation of Myocardial Perfusion and Function by Keeping Hypertrophied Heart Empty and Beating for Valve Surgery: An In Vivo MR Study of Pig Hearts.

    Science.gov (United States)

    Wang, Jian; Xiang, Bo; Deng, Jixian; Lin, Hung-Yu; Freed, Darren H; Arora, Rakesh C; Tian, Ganghong

    2017-01-01

    Objectives . Normothermic hyperkalemic cardioplegia arrest (NHCA) may not effectively preserve hypertrophied myocardium during open-heart surgery. Normothermic normokalemic beating perfusion (NNBP), keeping hearts empty-beating, was utilized as an alternative to evaluate its cardioprotective role. Materials and Methods . Twelve hypertrophied pig hearts at 58.6 ± 7.2 days after ascending aorta banding underwent NNBP and NHCA, respectively. Near infrared myocardial perfusion imaging with indocyanine green (ICG) was conducted to assess myocardial perfusion. Left ventricular (LV) contractile function was assessed by cine MRI. TUNEL staining and western blotting for caspase-3 cleavage and cardiac troponin I (cTnI) degradation were conducted in LV tissue samples. Results . Ascending aortic diameter was reduced by 52.7% ± 0.4% at approximately fifty-eight days after banding. LV wall thickness was significantly higher in aorta banding than in sham operation. Myocardial blood flow reflected by maximum ICG absorbance value was markedly higher in NNBP than in NHCA. The amount of apoptotic cardiomyocyte was significantly lower in NNBP than in NHCA. NNBP alleviated caspase-3 cleavage and cTnI degradation associated with NHCA. NNBP displayed a substantially increased postoperative ejection fraction relative to NHCA. Conclusions . NNBP was better than NHCA in enhancing myocardial perfusion, inhibiting cardiomyocyte apoptosis, and preserving LV contractile function for hypertrophied hearts.

  20. Extremes of fractional noises: A model for the timings of arrhythmic heart beats in post-infarction patients

    Science.gov (United States)

    Witt, Annette; Ehlers, Frithjof; Luther, Stefan

    2017-09-01

    We have analyzed symbol sequences of heart beat annotations obtained from 24-h electrocardiogram recordings of 184 post-infarction patients (from the Cardiac Arrhythmia Suppression Trial database, CAST). In the symbol sequences, each heart beat was coded as an arrhythmic or as a normal beat. The symbol sequences were analyzed with a model-based approach which relies on two-parametric peaks over the threshold (POT) model, interpreting each premature ventricular contraction (PVC) as an extreme event. For the POT model, we explored (i) the Shannon entropy which was estimated in terms of the Lempel-Ziv complexity, (ii) the shape parameter of the Weibull distribution that best fits the PVC return times, and (iii) the strength of long-range correlations quantified by detrended fluctuation analysis (DFA) for the two-dimensional parameter space. We have found that in the frame of our model the Lempel-Ziv complexity is functionally related to the shape parameter of the Weibull distribution. Thus, two complementary measures (entropy and strength of long-range correlations) are sufficient to characterize realizations of the two-parametric model. For the CAST data, we have found evidence for an intermediate strength of long-range correlations in the PVC timings, which are correlated to the age of the patient: younger post-infarction patients have higher strength of long-range correlations than older patients. The normalized Shannon entropy has values in the range 0.5

  1. Performance of a novel bipolar/monopolar radiofrequency ablation device on the beating heart in an acute porcine model.

    Science.gov (United States)

    Saint, Lindsey L; Lawrance, Christopher P; Okada, Shoichi; Kazui, Toshinobu; Robertson, Jason O; Schuessler, Richard B; Damiano, Ralph J

    2013-01-01

    Although the advent of ablation technology has simplified and shortened surgery for atrial fibrillation, only bipolar clamps have reliably been able to create transmural lesions on the beating heart. Currently, there are no devices capable of reproducibly creating the long linear lesions in the right and left atria needed to perform a Cox-Maze procedure. This study evaluated the performance of a novel suction-assisted radiofrequency device that uses both bipolar and monopolar energy to create lesions from an epicardial approach on the beating heart. Six domestic pigs underwent median sternotomy. A dual bipolar/monopolar radiofrequency ablation device was used to create epicardial linear lesions on the superior and inferior vena cavae, the right and left atrial free walls, and the right and left atrial appendages. The heart was stained with 2,3,5-triphenyl-tetrazolium chloride, and each lesion was cross-sectioned at 5-mm intervals. Lesion depth and transmurality were determined. Transmurality was documented in 94% of all cross sections, and 68% of all ablation lines were transmural along their entire length. Tissue thickness was not different between the transmural and nontransmural cross sections (3.1 ± 1.3 and 3.4 ± 2.1, P = 0.57, respectively), nor was the anatomic location on the heart (P = 0.45 for the distribution). Of the cross sections located at the end of the ablation line, 11% (8/75) were found to be nontransmural, whereas only 4% (8/195) of the cross sections located within the line of ablation were found to be nontransmural (P = 0.04). Logistic regression analysis demonstrated that failure of the device to create transmural lesions was associated with low body temperature (P = 0.006) but not with cardiac output (P = 0.54). This novel device was able to consistently create transmural epicardial lesions on the beating heart, regardless of anatomic location, cardiac output, or tissue thickness. The performance of this device was improved over most

  2. Total cavopulmonary direct anastomosis in the beating heart without prosthetic material: preliminary experience with modified extracardiac fontan procedure.

    Science.gov (United States)

    Xing, Quansheng; Shi, Lei; Han, Li; Wu, Qin

    2013-09-01

    To describe modified extracardiac Fontan procedure characterized with total cavopulmonary direct anastomosis in the beating heart without using prosthetic material in seven patients and summarize the clinical experiences and follow-up results. From April 2007 to April 2011, seven patients with complex cardiac anomalies underwent this operation. The main pulmonary artery (MPA) was transected at the base of the pulmonary valve and the pulmonary annulus was oversewn. Then the inferior vena cava (ICV) was transected at the junction with the atrium. The MPA was brought to the side of the ICV and anastomosed in an end-to-end fashion. The superior vena cava (SVC) was transected at its entrance into the right atrium and was anastomosed to the right pulmonary artery. Five patients received transcatheter device closure of the fenestration with either a small atrial septal defect or ventricular septal defect occluder. All patients were in sinus rhythm and extubated on the first postoperative day. Immediate postoperative arterial oxygen saturation was 95% (93% to 96%). During the follow-up period from 17 to 65 months (median 48 months), there were no deaths and reoperations. Arterial oxygen saturation ranged from 88% to 92% on room air. The fenestration was closed in five patients postoperatively and the arterial oxygen saturation rose to 95%. Total cavopulmonary direct anastomosis in the beating heart without the use of prosthetic material provides growth potential, and avoids the need for anticoagulation. Longer follow-up will be necessary to evaluate this modification. © 2013 Wiley Periodicals, Inc.

  3. From beat rate variability in induced pluripotent stem cell-derived pacemaker cells to heart rate variability in human subjects.

    Science.gov (United States)

    Ben-Ari, Meital; Schick, Revital; Barad, Lili; Novak, Atara; Ben-Ari, Erez; Lorber, Avraham; Itskovitz-Eldor, Joseph; Rosen, Michael R; Weissman, Amir; Binah, Ofer

    2014-10-01

    We previously reported that induced pluripotent stem cell-derived cardiomyocytes manifest beat rate variability (BRV) resembling heart rate variability (HRV) in the human sinoatrial node. We now hypothesized the BRV-HRV continuum originates in pacemaker cells. To investigate whether cellular BRV is a source of HRV dynamics, we hypothesized 3 levels of interaction among different cardiomyocyte entities: (1) single pacemaker cells, (2) networks of electrically coupled pacemaker cells, and (3) the in situ sinoatrial node. We measured BRV/HRV properties in single pacemaker cells, induced pluripotent stem cell-derived contracting embryoid bodies (EBs), and electrocardiograms from the same individual. Pronounced BRV/HRV was present at all 3 levels. The coefficient of variance of interbeat intervals and Poincaré plot indices SD1 and SD2 for single cells were 20 times greater than those for EBs (P heart (the latter two were similar; P > .05). We also compared BRV magnitude among single cells, small EBs (~5-10 cells), and larger EBs (>10 cells): BRV indices progressively increased with the decrease in the cell number (P heart rhythm. The decreased BRV magnitude in transitioning from the single cell to the EB suggests that the HRV of in situ hearts originates from the summation and integration of multiple cell-based oscillators. Hence, complex interactions among multiple pacemaker cells and intracellular Ca(2+) handling determine HRV in humans and cardiomyocyte networks. Copyright © 2014 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.

  4. Simulation of Ectopic Pacemakers in the Heart: Multiple Ectopic Beats Generated by Reentry inside Fibrotic Regions.

    Science.gov (United States)

    Gouvêa de Barros, Bruno; Weber dos Santos, Rodrigo; Lobosco, Marcelo; Alonso, Sergio

    2015-01-01

    The inclusion of nonconducting media, mimicking cardiac fibrosis, in two models of cardiac tissue produces the formation of ectopic beats. The fraction of nonconducting media in comparison with the fraction of healthy myocytes and the topological distribution of cells determines the probability of ectopic beat generation. First, a detailed subcellular microscopic model that accounts for the microstructure of the cardiac tissue is constructed and employed for the numerical simulation of action potential propagation. Next, an equivalent discrete model is implemented, which permits a faster integration of the equations. This discrete model is a simplified version of the microscopic model that maintains the distribution of connections between cells. Both models produce similar results when describing action potential propagation in homogeneous tissue; however, they slightly differ in the generation of ectopic beats in heterogeneous tissue. Nevertheless, both models present the generation of reentry inside fibrotic tissues. This kind of reentry restricted to microfibrosis regions can result in the formation of ectopic pacemakers, that is, regions that will generate a series of ectopic stimulus at a fast pacing rate. In turn, such activity has been related to trigger fibrillation in the atria and in the ventricles in clinical and animal studies.

  5. Simulation of Ectopic Pacemakers in the Heart: Multiple Ectopic Beats Generated by Reentry inside Fibrotic Regions

    Directory of Open Access Journals (Sweden)

    Bruno Gouvêa de Barros

    2015-01-01

    Full Text Available The inclusion of nonconducting media, mimicking cardiac fibrosis, in two models of cardiac tissue produces the formation of ectopic beats. The fraction of nonconducting media in comparison with the fraction of healthy myocytes and the topological distribution of cells determines the probability of ectopic beat generation. First, a detailed subcellular microscopic model that accounts for the microstructure of the cardiac tissue is constructed and employed for the numerical simulation of action potential propagation. Next, an equivalent discrete model is implemented, which permits a faster integration of the equations. This discrete model is a simplified version of the microscopic model that maintains the distribution of connections between cells. Both models produce similar results when describing action potential propagation in homogeneous tissue; however, they slightly differ in the generation of ectopic beats in heterogeneous tissue. Nevertheless, both models present the generation of reentry inside fibrotic tissues. This kind of reentry restricted to microfibrosis regions can result in the formation of ectopic pacemakers, that is, regions that will generate a series of ectopic stimulus at a fast pacing rate. In turn, such activity has been related to trigger fibrillation in the atria and in the ventricles in clinical and animal studies.

  6. Surgical on-pump beating-heart treatment of ischemic patients with low LF ejection fraction: immediate results

    Directory of Open Access Journals (Sweden)

    А. М. Чернявский

    2015-10-01

    Full Text Available Objectives. The study compares the early results of on-pump beating-heart (ONBEAT surgery versus conventional coronary artery bypass grafting (CABG with cardioplegic arrest (ONSTOP in patients with coronary artery disease and left ventricular dysfunction. Methods. In a single-center randomized trial, 60 patients operated for severe left ventricular dysfunction (EF<35% between January 2012 and January 2014 were randomized to ONBEAT (n=30 or ONSTOP (n=30 cohorts. All patients received preventive hemodynamic support before surgery (determined by randomization: intra-aortic balloon pump or levosimendan. Preoperative, operative and postoperative variables were evaluated in both groups. Results. Preoperative characteristics were similar between both groups. The time of stay in the ICU was 3 (2; 5 days in the first group and 3 (2; 4 days in the second one (p = 0.2. In the ONBEAT group 62 distal anastomoses (30 arterial were performed and in the ONSTOP group 70 distal anastomoses (30 arterial were done (p = 0.3. Completeness of revascularization on the beating heart corresponded to that in the group with cardioplegic arrest. The presence of complications such as stroke (p = 1.0, renal failure (p = 0.5, respiratory events (p = 0.2 and heart failure (p = 0.5 did not differ significantly between the two groups. Atrial fibrillation tended to occur more often in the postoperative period in the ONSTOP group (p = 0.03. The concentration of troponin I at all stages of the study did not differ significantly between the two groups. Both groups showed a significant increase in LV ejection fraction postoperatively: the first group 30 (26; 33 to 34 (30; 39 %, (p = 0,009; the second group - 31 (27 and 33 to 35 (30; 37 % (p = 0.01. Hospital mortality in the first group was observed in 1 case and in the second one in two cases (p = 0.5. Conclusions. The on-pump beating heart technique has no advantages comparing with conventional CABG in cases of preventive hemodynamic

  7. How sea ice could be the cold beating heart of European weather

    Science.gov (United States)

    Margrethe Ringgaard, Ida; Yang, Shuting; Hesselbjerg Christensen, Jens; Kaas, Eigil

    2017-04-01

    The possibility that the ongoing rapid demise of Arctic sea ice may instigate abrupt changes is, however, not tackled by current research in general. Ice cores from the Greenland Ice Sheet (GIS) show clear evidence of past abrupt warm events with up to 15 degrees warming in less than a decade, most likely triggered by rapid disappearance of Nordic Seas sea ice. At present, both Arctic Sea ice and the GIS are in strong transformation: Arctic sea-ice cover has been retreating during most of the satellite era and in recent years, Arctic sea ice experienced a dramatic reduction and the summer extent was in 2012 and 2016 only half of the 1979-2000 average. With such dramatic change in the current sea ice coverage as a point of departure, several studies have linked reduction in wintertime sea ice in the Barents-Kara seas to cold weather anomalies over Europe and through large scale tele-connections to regional warming elsewhere. Here we aim to investigate if, and how, Arctic sea ice impacts European weather, i.e. if the Arctic sea ice works as the 'cold heart' of European weather. To understand the effects of the sea ice reduction on the full climate system, a fully-coupled global climate model, EC-Earth, is used. A new energy-conserving method for assimilating sea ice using the sensible heat flux is implemented in the coupled climate model and compared to the traditional, non-conserving, method of assimilating sea ice. Using this new method, experiments are performed with reduced sea ice cover in the Barents-Kara seas under both warm and cold conditions in Europe. These experiments are used to evaluate how the Arctic sea ice modulates European winter weather under present climate conditions with a view towards favouring both relatively cold and warm conditions.

  8. Effect of trimetazidine and glucose- insulin-potassium use on myocard during beating heart coronary artery bypass surgery

    Directory of Open Access Journals (Sweden)

    Abdulkadir Ercan

    2011-12-01

    Full Text Available Objectives: This prospective, randomised, controlled, clinical study was planned to determine the effect of trimetazidine and glucose - insulin - potassium (GIK on myocardial ischemia-reperfusion during beating heart coronary artery bypass surgery.Materials and methods: Patients (n=45 with coronary artery disease who required beating heart coronary artery bypass grafting were randomly allocated into three groups. Patients in group 1 (n=15 was recevied trimetazidine (20 mg x 3 per day 7 days before surgery. Patients in group 2 (n=15 received GIK infusion after induction of anesthesia through the first 12 hours of intensive care unit convalescence. Patients in group 3 (n=15 were control group. Measurements of blood glucose, circulating creatine kinase MB (CK-MB and Troponin I (TnI concentrations were obtained before surgery, 5 minutes after completion of operation and at 12, 24, and 48 hours postoperatively. Mean pulmonary artery pressure, cardiac index, morbidity and data associated with operation were recorded in all patients preoperatively and postoperatively.Results: Preoperative risk profiles and operative variables were statistically similar when the groups were compared. The concentration of circulating CK-MB and Tn I significantly increased over time after off - pump coronary artery surgery, with no significant intergroup differences. Cardiac index and mean pulmonary artery pressure did not differ significantly between groups.Conclusion: Pretreatment with trimetazidine and GIK infusion protocol were used as an adjunct to ischemic - reperfusion therapy in off - pump coronary artery bypass surgery. These results suggested that pretreatment with trimetazidine and GIK infusion protocol do not significantly reduce ischemic reperfusion damage.

  9. Successful performance of Cox-Maze procedure on beating heart using bipolar radiofrequency ablation: a feasibility study in animals.

    Science.gov (United States)

    Gaynor, Sydney L; Ishii, Yosuke; Diodato, Michael D; Prasad, Sunil M; Barnett, Kara M; Damiano, Nicholas R; Byrd, Gregory D; Wickline, Samuel A; Schuessler, Richard B; Damiano, Ralph J

    2004-11-01

    The Cox-Maze procedure is the gold standard for the surgical treatment of atrial fibrillation with proven long-term efficacy. However, its application has been limited by its complexity and significant morbidity. The purpose of this study was to test the feasibility and safety of performing the Cox-Maze procedure using bipolar radiofrequency ablation on the beating heart without cardiopulmonary bypass. After median sternotomy, 6 Hanford mini-pigs underwent a modified Cox-Maze procedure using bipolar radiofrequency energy. The animals survived for 30 days. Atrial function, coronary artery, pulmonary vein anatomy, and valve function were assessed by magnetic resonance imaging. At reoperation, pacing documented electrical isolation of the pulmonary veins. Induction of atrial fibrillation was attempted by burst pacing with cholinergic stimulation. Histologic assessment was performed after sacrifice. There were no perioperative mortalities or neurologic events. At 30 days, atrial fibrillation was unable to be induced, and pulmonary vein isolation was confirmed by pacing. Magnetic resonance imaging assessment revealed no coronary artery or pulmonary vein stenoses. Although atrial ejection fraction decreased slightly from 0.344 +/- 0.0114 to 0.300 +/- 0.055 (p = 0.18), atrial contractility was preserved in every animal. Histologic assessment showed all lesions to be transmural, and there were no significant stenoses of the coronary vessels or injuries to the valves. Virtually all of the lesions of the Cox-Maze procedure can be performed without cardiopulmonary bypass using bipolar radiofrequency energy. There were no late stenoses of the pulmonary veins. Clinical trials of this new technology on the beating heart are warranted.

  10. Stereoscopic vision display technology in real-time three-dimensional echocardiography-guided intracardiac beating-heart surgery.

    Science.gov (United States)

    Vasilyev, Nikolay V; Novotny, Paul M; Martinez, Joseph F; Loyola, Hugo; Salgo, Ivan S; Howe, Robert D; del Nido, Pedro J

    2008-06-01

    Stereoscopic vision display technology has been shown to be a useful tool in image-guided surgical interventions. However, the concept has not been applied to 3-dimensional echocardiography-guided cardiac procedures. We evaluated stereoscopic vision display as an aid for intracardiac navigation during 3-dimensional echocardiography-guided beating-heart surgery in a model of atrial septal defect closure. An atrial septal defect (6 mm) was created in 6 pigs using 3-dimensional echocardiography guidance. The defect was then closed using a catheter-based patch delivery system, and the patch was attached with tissue mini-anchors. Stereoscopic vision was generated with a high-performance volume renderer with stereoscopic glasses. Three-dimensional echocardiography with stereoscopic vision display was compared with 3-dimensional echocardiography with standard display for guidance of surgical repair. Task performance measures for each anchor placement (N = 32 per group) were completion time, trajectory of the tip of the anchor deployment device, and accuracy of the anchor placement. The mean time of the anchor deployment for stereoscopic vision display group was shorter by 44% compared with the standard display group: 9.7 +/- 0.9 seconds versus 17.2 +/- 0.9 seconds (P display group versus 2.3 +/- 0.3 mm for the standard display group. Stereoscopic vision display combined with 3-dimensional echocardiography improved the visualization of 3-dimensional echocardiography ultrasound images, decreased the time required for surgical task completion, and increased the precision of instrument navigation, potentially improving the safety of beating-heart intracardiac surgical interventions.

  11. Regional differences in systolic active stress profiles in the normal beating heart. Assessment using an ultrasound based mathematical model.

    Science.gov (United States)

    McLaughlin, M; Langeland, S; Streb, W; Marciniak, M; D'Hooge, J; Bijnens, B; Claus, P

    2004-01-01

    Active stress (sigmaA) developed by cardiac muscle has been measured in isolated muscle preparations, under physiological loading conditions, by subtracting the passive stress (sigmaP) from the total stress (sigmaT). We previously developed a mechanical model based on M-mode ultrasound imaging to calculate these stresses in beating hearts. However, this model was based on one-dimensional imaging information and could not estimate regional differences in sigmaA. In the current study this model was improved by including two-dimensional B-mode echocardiographic data. In a porcine model a micro-manometer tipped catheter was used to measure left-ventricular pressure (LVP) and B-mode ultrasound images were recorded in a short-axis view. On the ultrasound image points in the mid-wall were selected and tracked to completely define the deformation of the myocardium. A kinematic model of the LV was then constructed from the displacement vectors of these points. sigmaT was calculated from the LVP. The material parameters for an exponential stress/strain relation were estimated during the diastolic E-wave when it was assumed that sigmaA = 0. These parameters were used to calculate sigmaP during systole and by subtracting this from sigmaT, sigmaA was calculated. The timing and shape of sigmaA profiles match those obtained from isolated muscle experiments. SigmaA was higher and peaked sooner in the posterior wall than in the anterior wall. Regional active stress estimation is possible in normal beating hearts.

  12. Coronary artery bypass grafting on the beating heart using the Octopus method

    NARCIS (Netherlands)

    Thijssens, K. M.; Rodrigus, I. E.; Amsel, B. J.; de Hert, S. G.; Moulijn, A. C.

    2000-01-01

    STUDY OBJECTIVE: To study the usefulness and effectiveness of off-pump coronary bypass grafting with the Octopus heart stabilizing device. METHOD: The files of thirty-one patients undergoing coronary artery bypass with the aid of the Octopus heart stabilizing device between April 1996 and October

  13. Development of an Ex Vivo, Beating Heart Model for CT Myocardial Perfusion

    NARCIS (Netherlands)

    Pelgrim, Gert Jan; Das, Marco; Haberland, Ulrike; Slump, Cees; Handayani, Astri; van Tuijl, Sjoerd; Stijnen, Marco; Klotz, Ernst; Oudkerk, Matthijs; Wildberger, Joachim E.; Vliegenthart, Rozemarijn

    2015-01-01

    Objective. To test the feasibility of a CT-compatible, ex vivo, perfused porcine heart model for myocardial perfusion CT imaging. Methods. One porcine heart was perfused according to Langendorff. Dynamic perfusion scanning was performed with a second-generation dual source CT scanner. Circulatory

  14. "And the Beat Goes Ona... Building Artificial Hearts in the Classroom.

    Science.gov (United States)

    Brock, David L.

    2000-01-01

    Among the many ideas and theories in anatomy and physiology, one particular topic provides all the potential benefits of learning about the human body: the circulatory system, specifically the heart. Describes a distinctive way to study circulation and the heart that allows students to explore the basic principles of vertebrate anatomy and…

  15. Normothermic ex vivo lung perfusion of non-heart-beating donor lungs in pigs : from pretransplant function analysis towards a 6-h machine preservation

    NARCIS (Netherlands)

    Erasmus, ME; Fernhout, MH; Elstrodt, JM; Rakhorst, G

    Donor shortage urges optimal use of all lungs available. Ex vivo lung perfusion (EVLP) is a method to evaluate lung function before implantation. EVLP was performed in pigs to evaluate lung function, using two different clinical non-heart-beating (NHS) donor protocols: flush perfusion and topical

  16. Multifactorial Biological Modulation of Warm Ischemia Reperfusion Injury in Liver Transplantation From Non-Heart-Beating Donors Eliminates Primary Nonfunction and Reduces Bile Salt Toxicity

    NARCIS (Netherlands)

    Monbaliu, Diethard; Vekemans, Katrien; Hoekstra, Harm; Vaahtera, Lauri; Libbrecht, Louis; Derveaux, Katelijne; Parkkinen, Jaakko; Liu, Qiang; Heedfeld, Veerle; Wylin, Tine; Deckx, Hugo; Zeegers, Marcel; Balligand, Erika; Buurman, Wim; van Pelt, Jos; Porte, Robert J.; Pirenne, Jacques

    2009-01-01

    Objective: To design a multifactorial biological modulation approach targeting ischemia reperfusion injury to augment viability of porcine liver grafts from non-heart-beating donors (NHBD). Background Data: Liver Transplantation (LTx) from NHBD is associated with an increased risk of primary

  17. The role of bile salt toxicity in the pathogenesis of bile duct injury after non-heart-beating porcine liver transplantation

    NARCIS (Netherlands)

    Yska, Marit J.; Buis, Carlijn I.; Monbaliu, Diethard; Schuurs, Theo A.; Gouw, Annette S. H.; Kahmann, Olivier N. H.; Visser, Dorien S.; Pirenne, Jacques; Porte, Robert J.

    2008-01-01

    Background. Intrahepatic bile duct strictures are a serious complication after non-heart-beating (NHB) liver transplantation. Bile salt toxicity has been identified as an important factor in the pathogenesis of bile duct injury and cholangiopathies. The role of bile salt toxicity in the development

  18. Early Reperfusion Hemodynamics Predict Recovery in Rat Hearts: A Potential Approach towards Evaluating Cardiac Grafts from Non-Heart-Beating Donors

    Science.gov (United States)

    Dornbierer, Monika; Stadelmann, Mathieu; Sourdon, Joevin; Gahl, Brigitta; Cook, Stéphane; Carrel, Thierry P.; Tevaearai, Hendrik T.; Longnus, Sarah L.

    2012-01-01

    Aims Cardiac grafts from non-heartbeating donors (NHBDs) could significantly increase organ availability and reduce waiting-list mortality. Reluctance to exploit hearts from NHBDs arises from obligatory delays in procurement leading to periods of warm ischemia and possible subsequent contractile dysfunction. Means for early prediction of graft suitability prior to transplantation are thus required for development of heart transplantation programs with NHBDs. Methods and Results Hearts (n = 31) isolated from male Wistar rats were perfused with modified Krebs-Henseleit buffer aerobically for 20 min, followed by global, no-flow ischemia (32°C) for 30, 50, 55 or 60 min. Reperfusion was unloaded for 20 min, and then loaded, in working-mode, for 40 min. Left ventricular (LV) pressure was monitored using a micro-tip pressure catheter introduced via the mitral valve. Several hemodynamic parameters measured during early, unloaded reperfusion correlated significantly with LV work after 60 min reperfusion (p<0.001). Coronary flow and the production of lactate and lactate dehydrogenase (LDH) also correlated significantly with outcomes after 60 min reperfusion (p<0.05). Based on early reperfusion hemodynamic measures, a composite, weighted predictive parameter, incorporating heart rate (HR), developed pressure (DP) and end-diastolic pressure, was generated and evaluated against the HR-DP product after 60 min of reperfusion. Effective discriminating ability for this novel parameter was observed for four HR*DP cut-off values, particularly for ≥20 *103 mmHg*beats*min−1 (p<0.01). Conclusion Upon reperfusion of a NHBD heart, early evaluation, at the time of organ procurement, of cardiac hemodynamic parameters, as well as easily accessible markers of metabolism and necrosis seem to accurately predict subsequent contractile recovery and could thus potentially be of use in guiding the decision of accepting the ischemic heart for transplantation. PMID:22928009

  19. Early reperfusion hemodynamics predict recovery in rat hearts: a potential approach towards evaluating cardiac grafts from non-heart-beating donors.

    Directory of Open Access Journals (Sweden)

    Monika Dornbierer

    Full Text Available AIMS: Cardiac grafts from non-heartbeating donors (NHBDs could significantly increase organ availability and reduce waiting-list mortality. Reluctance to exploit hearts from NHBDs arises from obligatory delays in procurement leading to periods of warm ischemia and possible subsequent contractile dysfunction. Means for early prediction of graft suitability prior to transplantation are thus required for development of heart transplantation programs with NHBDs. METHODS AND RESULTS: Hearts (n = 31 isolated from male Wistar rats were perfused with modified Krebs-Henseleit buffer aerobically for 20 min, followed by global, no-flow ischemia (32°C for 30, 50, 55 or 60 min. Reperfusion was unloaded for 20 min, and then loaded, in working-mode, for 40 min. Left ventricular (LV pressure was monitored using a micro-tip pressure catheter introduced via the mitral valve. Several hemodynamic parameters measured during early, unloaded reperfusion correlated significantly with LV work after 60 min reperfusion (p<0.001. Coronary flow and the production of lactate and lactate dehydrogenase (LDH also correlated significantly with outcomes after 60 min reperfusion (p<0.05. Based on early reperfusion hemodynamic measures, a composite, weighted predictive parameter, incorporating heart rate (HR, developed pressure (DP and end-diastolic pressure, was generated and evaluated against the HR-DP product after 60 min of reperfusion. Effective discriminating ability for this novel parameter was observed for four HR*DP cut-off values, particularly for ≥20 *10(3 mmHg*beats*min(-1 (p<0.01. CONCLUSION: Upon reperfusion of a NHBD heart, early evaluation, at the time of organ procurement, of cardiac hemodynamic parameters, as well as easily accessible markers of metabolism and necrosis seem to accurately predict subsequent contractile recovery and could thus potentially be of use in guiding the decision of accepting the ischemic heart for transplantation.

  20. Hearts beating through decellularized scaffolds: whole-organ engineering for cardiac regeneration and transplantation.

    Science.gov (United States)

    Zia, Sonia; Mozafari, Masoud; Natasha, G; Tan, Aaron; Cui, Zhanfeng; Seifalian, Alexander M

    2016-08-01

    Whole-organ decellularization and tissue engineering approaches have made significant inroads during recent years. If proven to be successful and clinically viable, it is highly likely that this field would be poised to revolutionize organ transplantation surgery. In particular, whole-heart decellularization has captured the attention and imagination of the scientific community. This technique allows for the generation of a complex three-dimensional (3D) extracellular matrix scaffold, with the preservation of the intrinsic 3D basket-weave macroarchitecture of the heart itself. The decellularized scaffold can then be recellularized by seeding it with cells and incubating it in perfusion bioreactors in order to create functional organ constructs for transplantation. Indeed, research into this strategy of whole-heart tissue engineering has consequently emerged from the pages of science fiction into a proof-of-concept laboratory undertaking. This review presents current trends and advances, and critically appraises the concepts involved in various approaches to whole-heart decellularization and tissue engineering.

  1. Multiple capture locations for 3D ultrasound-guided robotic retrieval of moving bodies from a beating heart

    Science.gov (United States)

    Thienphrapa, Paul; Ramachandran, Bharat; Elhawary, Haytham; Taylor, Russell H.; Popovic, Aleksandra

    2012-02-01

    Free moving bodies in the heart pose a serious health risk as they may be released in the arteries causing blood flow disruption. These bodies may be the result of various medical conditions and trauma. The conventional approach to removing these objects involves open surgery with sternotomy, the use of cardiopulmonary bypass, and a wide resection of the heart muscle. We advocate a minimally invasive surgical approach using a flexible robotic end effector guided by 3D transesophageal echocardiography. In a phantom study, we track a moving body in a beating heart using a modified normalized cross-correlation method, with mean RMS errors of 2.3 mm. We previously found the foreign body motion to be fast and abrupt, rendering infeasible a retrieval method based on direct tracking. We proposed a strategy based on guiding a robot to the most spatially probable location of the fragment and securing it upon its reentry to said location. To improve efficacy in the context of a robotic retrieval system, we extend this approach by exploring multiple candidate capture locations. Salient locations are identified based on spatial probability, dwell time, and visit frequency; secondary locations are also examined. Aggregate results indicate that the location of highest spatial probability (50% occupancy) is distinct from the longest-dwelled location (0.84 seconds). Such metrics are vital in informing the design of a retrieval system and capture strategies, and they can be computed intraoperatively to select the best capture location based on constraints such as workspace, time, and device manipulability. Given the complex nature of fragment motion, the ability to analyze multiple capture locations is a desirable capability in an interventional system.

  2. Far beyond the Sun - I. The beating magnetic heart in Horologium

    Science.gov (United States)

    Alvarado-Gómez, Julián D.; Hussain, Gaitee A. J.; Drake, Jeremy J.; Donati, Jean-François; Sanz-Forcada, Jorge; Stelzer, Beate; Cohen, Ofer; Amazo-Gómez, Eliana M.; Grunhut, Jason H.; Garraffo, Cecilia; Moschou, Sofia P.; Silvester, James; Oksala, Mary E.

    2018-02-01

    A former member of the Hyades cluster, ι Horologii (ι Hor) is a planet-hosting Sun-like star which displays the shortest coronal activity cycle known to date (Pcyc ∼ 1.6 yr). With an age of ∼625 Myr, ι Hor is also the youngest star with a detected activity cycle. The study of its magnetic properties holds the potential to provide fundamental information to understand the origin of cyclic activity and stellar magnetism in late-type stars. In this series of papers, we present the results of a comprehensive project aimed at studying the evolving magnetic field in this star and how this evolution influences its circumstellar environment. This paper summarizes the first stage of this investigation, with results from a long-term observing campaign of ι Hor using ground-based high-resolution spectropolarimetry. The analysis includes precise measurements of the magnetic activity and radial velocity of the star, and their multiple time-scales of variability. In combination with values reported in the literature, we show that the long-term chromospheric activity evolution of ι Hor follows a beating pattern, caused by the superposition of two periodic signals of similar amplitude at P1 ≃ 1.97 ± 0.02 yr and P2 ≃ 1.41 ± 0.01 yr. Additionally, using the most recent parameters for ι Hor b in combination with our activity and radial velocity measurements, we find that stellar activity dominates the radial velocity residuals, making the detection of additional planets in this system challenging. Finally, we report here the first measurements of the surface longitudinal magnetic field strength of ι Hor, which displays varying amplitudes within ±4 G and served to estimate the rotation period of the star (P_rot = 7.70^{+0.18}_{-0.67} d).

  3. Distinguishing between overdrive excited and suppressed ventricular beats in guinea pig ventricular myocardium

    Directory of Open Access Journals (Sweden)

    Amara eGreer-Short

    2015-02-01

    Full Text Available Rapid ventricular pacing rates induces two types of beats following pacing cessation: recovery cycle length (RCL prolongation (overdrive suppression and RCL shortening (overdrive excitation. The goals of this study were to compare common experimental protocols for studying triggered activity in whole-heart preparations and differentiate between recovery beats using a new methodology. Post-pacing recovery beat cycle length (RCL and QRS were normalized to pre-paced R-R and QRS intervals and analyzed using a K-means clustering algorithm. Control hearts only produced suppressed beats: RCL ratio increased with rapid pacing (25±4.0%, n=10 without changing QRS duration. Rapid pacing during hypercalcemia + hypothermia (5.5 mM and 34°C produced significantly earlier excited beats (53±14%, n=5 with wider QRS durations (58±6.3%, n=5 than suppressed beats. Digoxin + hypothermia (0.75 M produced the most excited beats with significantly earlier RCL (44±3.2%, n=6 and wider QRS (60±3.1%, n=6 ratios relative to suppressed beats. Increasing pacing further shortened RCL (30±7.8%, n=6. In a prospective study, TTX (100 nM increased RCL ratio (15±6.0%, n=10 without changing the QRS duration of excited beats. The algorithm was compared to a cross-correlation analysis with 93% sensitivity and 94% specificity. This ECG based algorithm distinguishes between triggered and automatic activity.

  4. A computer heart model incorporating anisotropic propagation. III. Simulation of ectopic beats.

    Science.gov (United States)

    Xu, Z; Gulrajani, R M; Molin, F; Lorange, M; Dubé, B; Savard, P; Nadeau, R A

    1996-04-01

    With the advent of catheter ablation procedures, it has become an important goal to predict noninvasively the site of origin of ventricular tachycardia. Site classifications based on the observed body surface potential maps (BSPMs) during ventricular endocardial pacing, as well as on the patterns of the QRS integrals of these maps, have been suggested. The goals of this study were to verify these maps and their QRS integral patterns via simulation using a computer heart model with realistic geometry and to determine whether the model could improve clinical understanding of these ectopic patterns. Simulation was achieved by initiating excitation of the heart model at different endocardial sites and their overlying epicardial counterparts. This excitation propagated in anisotropic fashion in the myocardium. Retrograde excitation of the model's His-Purkinje conduction system was necessary to obtain realistic activation durations. Simulated BSPMs, computed by placing the heart model inside a numerical torso model, and their QRS integrals were close to those observed clinically. Small differences in QRS integral map patterns and in the positions of the QRS integral map extrema were noted for endocardial sites in the left septal and anteroseptal regions. The simulated BSPMs during early QRS for an endocardial site and its epicardial counterpart tended to be mirror images about the zero isopotential contour, exchanging positive and negative map regions. The simulation results attest to the model's ability to reproduce accurately clinically recorded body surface potential distributions obtained following endocardial stimulation. The QRS integral maps from endocardial sites in the left septal and anteroseptal regions were the most labile, owing to considerable cancellation effects. Conventional BSPMs can be useful to help distinguish between endocardial and epicardial ectopic sites.

  5. Maintenance of cAMP in non-heart-beating donor lungs reduces ischemia-reperfusion injury.

    Science.gov (United States)

    Hoffmann, S C; Bleiweis, M S; Jones, D R; Paik, H C; Ciriaco, P; Egan, T M

    2001-06-01

    Studies suggest that pulmonary vascular ischemia-reperfusion injury (IRI) can be attenuated by increasing intracellular cAMP concentrations. The purpose of this study was to determine the effect of IRI on capillary permeability, assessed by capillary filtration coeficient (Kfc), in lungs retrieved from non-heart-beating donors (NHBDs) and reperfused with the addition of the beta(2)-adrenergic receptor agonist isoproterenol (iso), and rolipram (roli), a phosphodiesterase (type IV) inhibitor. Using an in situ isolated perfused lung model, lungs were retrieved from NHBD rats at varying intervals after death and either ventilated with O(2) or not ventilated. The lungs were reperfused with Earle's solution with or without a combination of iso (10 microM) and roli (2 microM). Kfc, lung viability, and pulmonary hemodynamics were measured. Lung tissue levels of adenine nucleotides and cAMP were measured by HPLC. Combined iso and roli (iso/roli) reperfusion decreased Kfc significantly (p Kfc in non-iso/roli-reperfused (r = 0.89) and iso/roli-reperfused (r = 0.97) lungs. cAMP levels correlated with Kfc (r = 0.93) in iso/roli-reperfused lungs. Pharmacologic augmentation of tissue TAN and cAMP levels might ameliorate the increased capillary permeability observed in lungs retrieved from NHBDs.

  6. Detection of inflating balloon in optical coherence tomography images of a porcine artery in a beating heart experiment

    Science.gov (United States)

    Azarnoush, Hamed; Vergnole, Sébastien; Hewko, Mark; Boulet, Benoit; Sowa, Mike; Lamouche, Guy

    2011-03-01

    Suboptimal results of angioplasty procedures have been correlated to arterial damage during balloon inflation. We propose to monitor balloon inflation during the angioplasty procedure by detecting the balloon contours with intravascular optical coherence tomography (IVOCT). This will shed more light on the interaction between the balloon and the artery and to assess the artery's mechanical response. An automatic edge detection algorithm is applied for detection of the outer surface of an inflating balloon in a porcine artery in a beating heart experiment. A compliant balloon is inflated to deform the artery. IVOCT monitoring of balloon inflation is performed at a rate of 30 frames per second. During inflation, the balloon engages the arterial wall. Therefore, the characterization of the diameter of the inflated balloon leads to a characterization of the luminal diameter of the vessel. This provides precise information about the artery response to a simulated angioplasty procedure, information currently not provided by any other existing technique. In the current experiment, balloon inflation characterization is based on 356 IVOCT frames during which the estimated balloon diameter increases approximately from 1.8 mm to 2.9 mm.

  7. Fibrinolytic preflush upon liver retrieval from non-heart beating donors to enhance postpreservation viability and energetic recovery upon reperfusion.

    Science.gov (United States)

    Minor, T; Hachenberg, A; Tolba, R; Pauleit, D; Akbar, S

    2001-06-27

    Our objective was to evaluate graft equilibration with high viscosity (University of Wisconsin solution [UW]) or low viscosity (Bretschneider's histidine-tryptophan-ketoglutarate [HTK]) during liver procurement from non-heart beating donors (NHBD) and the potential impact of a preceding fibrinolysis with streptokinase on postpreservation viability. After 60 min of cardiac arrest, rat livers were perfused by gravity (60 cm H2O) via the portal vein with either 60 ml of HTK, 20 ml of UW, or 20 ml of Ringer's solution (22 degrees C including 7500U of streptokinase) and, subsequently, 20 ml of UW. After 24 h of storage at 4 degrees C, viability of the livers was assessed upon isolated reperfusion in vitro. Magnetic resonance imaging revealed severe perfusion deficits, which were mildly attenuated with HTK, upon flush-out with UW. After preflush with streptokinase, a mostly homogenous distribution of the preservation solution was observed throughout the liver tissue. The choice of the flush-out solution (UW or HTK) had no influence on parenchymal enzyme leakage, hepatic bile production, or tissue levels of ATP after reperfusion of the livers. Fibrinolytic preflush, however, resulted in a relevant and significant improvement of structural integrity as well as functional and metabolic recovery. Compromised vascular tissue perfusion upon organ harvest in NHBD triggers graft dysfunction after cold storage and can easily be circumvented by temporary fibrinolysis before graft retrieval.

  8. [THEORETICAL BACKGROUND OF FINDING ORGANS FOR TRANSPLANTATION AMONG NON-HEART BEATING DONORS UNDER UNSUCCESSFUL EXTRACORPOREAL RESUSCITATION (LITERATURE REVIEW)].

    Science.gov (United States)

    Khodeli, N; Chkhaidze, Z; Partsakhashvili, D; Pilishvili, O; Kordzaia, D

    2016-05-01

    The number of patients who are in the "Transplant Waiting List" is increasing each year. At the same time, as a result of the significant shortage of donor organs, part of the patients dies without waiting till surgery. According to the Maastricht classification for non-heart beating donors, the patients, who had cardiac arrest outside the hospital (in the uncontrolled by medical staff conditions) should be considered as a potential donors of category II. For these patients, the most effective resuscitation is recommended. The extracorporeal life support (ECLS) considers the connection to a special artificial perfusion system for the restoration of blood circulation out-of-hospital with further transportation to the hospital. If restoration of independent cardiac activity does not occur, in spite of the full range of resuscitative measures, these patients may be regarded as potential donors. The final decision should be received in the hospital, by the council of physicians, lawyers and patient's family members. Until the final decision, the prolongation of ECLS and maintaining adequate systemic and organic circulation is recommended.

  9. Effects of phenylephrine and noradrenaline on coronary artery motion in an open-chest porcine beating heart model.

    Science.gov (United States)

    Kurosawa, Hiroyuki; Seto, Yuki; Wakamatsu, Hiroki; Sato, Yoshiyuki; Takase, Shinya; Omata, Sadao; Yokoyama, Hitoshi

    2014-06-01

    During off-pump coronary artery bypass (OPCAB), surgeons are required to perform a precise anastomosis on the beating heart. The hypotension caused by vertical displacement of the heart during OPCAB is usually treated with vasopressors, such as noradrenaline and phenylephrine. However, the effects of these agents on coronary artery motion are unknown. The present study analyzed the motion of the target coronary arteries during noradrenaline or phenylephrine infusion using three-dimensional motion capture and reconstruction technology. The left anterior descending (LAD) artery, left circumflex (LCX) artery and right coronary artery (RCA) of 12 female landrace pigs (weight 50 ± 1 kg) were stabilized using a tissue stabilizer. The motions in the regions were captured before and during noradrenaline (n = 5) and phenylephrine (n = 7) infusion. Noradrenaline (0.15 μg/kg/min) and phenylephrine (1.1 μg/kg/min) significantly increased the blood pressure. Noradrenaline significantly increased the motion parameters, such as the distance moved, maximum velocity, acceleration and deceleration at the LAD (4.2 vs. 7.9 mm, P = 0.025; 95.7 vs. 215.5 mm/s, P = 0.0074; 35.3 vs. 83.6 m/s(2), P = 0.0096 and -35.6 vs. -83.6 m/s(2), P = 0.005, respectively). The values during phenylephrine infusion did not change except for the distance moved at the LAD (3.8 vs. 7.7 mm, P = 0.042). The motion parameters at the LCX and RCA during noradrenaline and phenylephrine infusion did not change significantly. The effect of phenylephrine on the coronary artery motion was less dramatic than that of noradrenaline.

  10. Using an elastic magnifier to increase power output and performance of heart-beat harvesters

    Science.gov (United States)

    Galbier, Antonio C.; Karami, M. Amin

    2017-09-01

    Embedded piezoelectric energy harvesting (PEH) systems in medical pacemakers have been a growing and innovative research area. The goal of these systems, at present, is to remove the pacemaker battery, which makes up 60%-80% of the unit, and replace it with a sustainable power source. This requires that energy harvesting systems provide sufficient power, 1-3 μW, for operating a pacemaker. The goal of this work is to develop, test, and simulate cantilevered energy harvesters with a linear elastic magnifier (LEM). This research hopes to provide insight into the interaction between pacemaker energy harvesters and the heart. By introducing the elastic magnifier into linear and nonlinear systems oscillations of the tip are encouraged into high energy orbits and large tip deflections. A continuous nonlinear model is presented for the bistable piezoelectric energy harvesting (BPEH) system and a one-degree-of-freedom linear mass-spring-damper model is presented for the elastic magnifier. The elastic magnifier will not consider the damping negligible, unlike most models. A physical model was created for the bistable structure and formed to an elastic magnifier. A hydrogel was designed for the experimental model for the LEM. Experimental results show that the BPEH coupled with a LEM (BPEH + LEM) produces more power at certain input frequencies and operates a larger bandwidth than a PEH, BPEH, and a standard piezoelectric energy harvester with the elastic magnifier (PEH + LEM). Numerical simulations are consistent with these results. It was observed that the system enters high-energy and high orbit oscillations and that, ultimately, BPEH systems implemented in medical pacemakers can, if designed properly, have enhanced performance if positioned over the heart.

  11. Performance of Fixed Heart Rate Increment Targets of 20 vs 30 Beats per Minute for Exercise Rehabilitation Prescription in Outpatients With Heart Failure.

    Science.gov (United States)

    Reed, Jennifer L; Blais, Angelica Z; Keast, Marja-Leena; Pipe, Andrew L; Reid, Robert D

    2017-06-01

    Patients with heart failure (HF) should exercise at 40%-60% heart rate reserve (HRR) during the first 3 weeks of an outpatient cardiac rehabilitation (CR) program and at 50%-80% HRR thereafter. Arbitrary methods to prescribe exercise intensity such as resting HR (RHR) plus 20 or 30 beats per minute (bpm) (RHR + 20 or RHR + 30) are recommended for inpatients after a myocardial infarction or those recovering from heart surgery. This approach has been repurposed by outpatient CR programs to prescribe exercise intensity for patients with HF, yet its efficacy has not been evaluated. We examined the appropriateness of RHR + 20/30 for prescribing exercise intensity and improving functional capacity for 55 patients with HF in an outpatient CR program. RHR + 20/30 values were compared to % HRR derived from peak exercise testing in patients with HF. Changes in functional capacity as measured by 6-minute walk test (6MWT) distance, and differences in ratings of perceived exertion (RPE), were examined between patients exercising at RHR + 20-29 and those exercising at RHR + ≥ 30. During weeks 1-3 and exercise at RHR + 20, 26% of participants would exercise at 40%-60% HRR. At RHR + 30, 38% would exercise at 40%-60% HRR. During weeks 4-12 and exercise at RHR + 20, 20% of participants would exercise at 50%-80% HRR. At RHR + 30, 41% would exercise at 50%-80% HRR. A smaller change in 6MWT distance was observed in participants exercising at RHR + 20-29 than in those exercising at RHR + ≥ 30 (Δ86.6 ± 70.3 vs Δ135.8 ± 73.7 m; P = 0.005). No differences in RPE were observed between participants exercising at RHR + 20-29 and those exercising at RHR + ≥ 30 (P > 0.05). RHR + 30 was more effective than RHR + 20 in assisting outpatients with HF achieve recommended exercise intensities and improve functional capacity. Copyright © 2017 Canadian Cardiovascular Society. Published by Elsevier Inc. All rights reserved.

  12. Effectiveness of Remote Patient Monitoring After Discharge of Hospitalized Patients With Heart Failure: The Better Effectiveness After Transition–Heart Failure (BEAT-HF) Randomized Clinical Trial

    Science.gov (United States)

    Ong, Michael K.; Romano, Patrick S.; Edgington, Sarah; Aronow, Harriet U.; Auerbach, Andrew D.; Black, Jeanne T.; De Marco, Teresa; Escarce, Jose J.; Evangelista, Lorraine S.; Hanna, Barbara; Ganiats, Theodore G.; Greenberg, Barry H.; Greenfield, Sheldon; Kaplan, Sherrie H.; Kimchi, Asher; Liu, Honghu; Lombardo, Dawn; Mangione, Carol M.; Sadeghi, Bahman; Sadeghi, Banafsheh; Sarrafzadeh, Majid; Tong, Kathleen; Fonarow, Gregg C.

    2016-01-01

    Importance It remains unclear whether telemonitoring approaches provide benefits for patients with heart failure (HF) after hospitalization. Objective To evaluate the effectiveness of a care transition intervention using remote patient monitoring in reducing 180-day all-cause readmissions among a broad population of older adults hospitalized with HF. Design, Setting, and Participants We randomized 1437 patients hospitalized for HF between October 12, 2011, and September 30, 2013, to the intervention arm (715 patients) or to the usual care arm (722 patients) of the Better Effectiveness After Transition–Heart Failure (BEAT-HF) study and observed them for 180 days. The dates of our study analysis were March 30, 2014, to October 1, 2015. The setting was 6 academic medical centers in California. Participants were hospitalized individuals 50 years or older who received active treatment for decompensated HF. Interventions The intervention combined health coaching telephone calls and telemonitoring. Telemonitoring used electronic equipment that collected daily information about blood pressure, heart rate, symptoms, and weight. Centralized registered nurses conducted telemonitoring reviews, protocolized actions, and telephone calls. Main outcomes and measures The primary outcome was readmission for any cause within 180 days after discharge. Secondary outcomes were all-cause readmission within 30 days, all-cause mortality at 30 and 180 days, and quality of life at 30 and 180 days. Results Among 1437 participants, the median age was 73 years. Overall, 46.2% (664 of 1437) were female, and 22.0% (316 of 1437) were African American. The intervention and usual care groups did not differ significantly in readmissions for any cause 180 days after discharge, which occurred in 50.8% (363 of 715) and 49.2% (355 of 722) of patients, respectively (adjusted hazard ratio, 1.03; 95% CI, 0.88-1.20; P = .74). In secondary analyses, there were no significant differences in 30-day

  13. Auxotonic to isometric contraction transitioning in a beating heart causes myosin step-size to down shift.

    Directory of Open Access Journals (Sweden)

    Thomas P Burghardt

    Full Text Available Myosin motors in cardiac ventriculum convert ATP free energy to the work of moving blood volume under pressure. The actin bound motor cyclically rotates its lever-arm/light-chain complex linking motor generated torque to the myosin filament backbone and translating actin against resisting force. Previous research showed that the unloaded in vitro motor is described with high precision by single molecule mechanical characteristics including unitary step-sizes of approximately 3, 5, and 8 nm and their relative step-frequencies of approximately 13, 50, and 37%. The 3 and 8 nm unitary step-sizes are dependent on myosin essential light chain (ELC N-terminus actin binding. Step-size and step-frequency quantitation specifies in vitro motor function including duty-ratio, power, and strain sensitivity metrics. In vivo, motors integrated into the muscle sarcomere form the more complex and hierarchically functioning muscle machine. The goal of the research reported here is to measure single myosin step-size and step-frequency in vivo to assess how tissue integration impacts motor function. A photoactivatable GFP tags the ventriculum myosin lever-arm/light-chain complex in the beating heart of a live zebrafish embryo. Detected single GFP emission reports time-resolved myosin lever-arm orientation interpreted as step-size and step-frequency providing single myosin mechanical characteristics over the active cycle. Following step-frequency of cardiac ventriculum myosin transitioning from low to high force in relaxed to auxotonic to isometric contraction phases indicates that the imposition of resisting force during contraction causes the motor to down-shift to the 3 nm step-size accounting for >80% of all the steps in the near-isometric phase. At peak force, the ATP initiated actomyosin dissociation is the predominant strain inhibited transition in the native myosin contraction cycle. The proposed model for motor down-shifting and strain sensing involves ELC N

  14. Is High Temporal Resolution Achievable for Paediatric Cardiac Acquisitions during Several Heart Beats? Illustration with Cardiac Phase Contrast Cine-MRI.

    Directory of Open Access Journals (Sweden)

    Laurent Bonnemains

    Full Text Available During paediatric cardiac Cine-MRI, data acquired during cycles of different lengths must be combined. Most of the time, Feinstein's model is used to project multiple cardiac cycles of variable lengths into a mean cycle.To assess the effect of Feinstein projection on temporal resolution of Cine-MRI.1/The temporal errors during Feinstein's projection were computed in 306 cardiac cycles fully characterized by tissue Doppler imaging with 6-phase analysis (from a population of 7 children and young adults. 2/The effects of these temporal errors on tissue velocities were assessed by simulating typical tissue phase mapping acquisitions and reconstructions. 3/Myocardial velocities curves, extracted from high-resolution phase-contrast cine images, were compared for the 6 volunteers with lowest and highest heart rate variability, within a population of 36 young adults.1/The mean of temporal misalignments was 30 ms over the cardiac cycle but reached 60 ms during early diastole. 2/During phase contrast MRI simulation, early diastole velocity peaks were diminished by 6.1 cm/s leading to virtual disappearance of isovolumic relaxation peaks. 3/The smoothing and erasing of isovolumic relaxation peaks was confirmed on tissue phase mapping velocity curves, between subjects with low and high heart rate variability (p = 0.05.Feinstein cardiac model creates temporal misalignments that impair high temporal resolution phase contrast cine imaging when beat-to-beat heart rate is changing.

  15. ProSeal laryngeal mask airway as an alternative to standard endotracheal tube in securing upper airway in the patients undergoing beating-heart coronary artery bypass grafting

    Directory of Open Access Journals (Sweden)

    Kalpana Shah

    2017-01-01

    Full Text Available Background: ProSeal laryngeal mask airways (PLMAs are routinely used after failed tracheal intubation as airway rescue, facilitating tracheal intubation by acting as a conduit and to secure airway during emergencies. In long duration surgeries, use of endotracheal tube (ETT is associated with various hemodynamic complications, which are minimally affected during PLMA use. However, except for few studies, there are no significant data available that promote the use of laryngeal mask during cardiac surgery. This prospective study was conducted with the objective of demonstrating the advantages of PLMA over ETT in the patients undergoing beating-heart coronary artery bypass graft (CABG. Methodology: This prospective, interventional study was carried out in 200 patients who underwent beating-heart CABG. Patients were randomized in equal numbers to either ETT group or PLMA group, and various hemodynamic and respiratory parameters were observed at different time points. Results: Patients in PLMA group had mean systolic blood pressure 126.10 ± 5.31 mmHg compared to the patients of ETT group 143.75 ± 6.02 mmHg. Pulse rate in the PLMA group was less (74.52 ± 10.79 per min (P < 0.05 compared to ETT group (81.72 ± 9.8. Thus, hemodynamic changes were significantly lower (P < 0.05 in PLMA than in ETT group. Respiratory parameters such as oxygen saturation, pressure CO 2 (pCO 2 , peak airway pressure, and lung compliance were similar to ETT group at all evaluation times. The incidence of adverse events was also lower in PLMA group. Conclusion: In experience hand, PLMA offers advantages over the ETT in airway management in the patients undergoing beating-heart CABG.

  16. An Experimental Study in Generative Music for Exercising to Ease Perceived Exertion by use of Heart Beat Rate as a Control Parameter

    DEFF Research Database (Denmark)

    Serafin, Stefania; Erkut, Cumhur

    This paper investigates whether generative music, adapted to a user's heart beat rate, can be used to ease the perceived exertion. A generative system was implemented and tested on 13 test participants in a controlled environment on a training bike. The test participants performed a cycling workout...... of three minutes in two conditions in a self-chosen pace, with and without music. Their pulse were used as the physiological exertion. The perceived exertion was rated by the test participants according to Borg’s 6-20 exertion scale. Five out of 13 participants showed indications supporting the notion......, while 2 out of 13 indicated the opposite. 6 out of 13 participants neither showed indications supporting nor opposing the theory. The results could be useful for exercises, where the change of heart pulse is gradual, but further work is needed in cadance-based exercises....

  17. Effects of exogenous surfactant on the non-heart-beating donor lung graft in experimental lung transplantation – a stereological study

    Science.gov (United States)

    Herrmann, Gudrun; Knudsen, Lars; Madershahian, Navid; Mühlfeld, Christian; Frank, Konrad; Rahmanian, Parwis; Wahlers, Thorsten; Wittwer, Thorsten; Ochs, Matthias

    2014-01-01

    The use of non-heart-beating donor (NHBD) lungs may help to overcome the shortage of lung grafts in clinical lung transplantation, but warm ischaemia and ischaemia/reperfusion injury (I/R injury) resulting in primary graft dysfunction represent a considerable threat. Thus, better strategies for optimized preservation of lung grafts are urgently needed. Surfactant dysfunction has been shown to contribute to I/R injury, and surfactant replacement therapy is effective in enhancing lung function and structural integrity in related rat models. In the present study we hypothesize that surfactant replacement therapy reduces oedema formation in a pig model of NHBD lung transplantation. Oedema formation was quantified with (SF) and without (non-SF) surfactant replacement therapy in interstitial and alveolar compartments by means of design-based stereology in NHBD lungs 7 h after cardiac arrest, reperfusion and transplantation. A sham-operated group served as control. In both NHBD groups, nearly all animals died within the first hours after transplantation due to right heart failure. Both SF and non-SF developed an interstitial oedema of similar degree, as shown by an increase in septal wall volume and arithmetic mean thickness as well as an increase in the volume of peribron-chovascular connective tissue. Regarding intra-alveolar oedema, no statistically significant difference could be found between SF and non-SF. In conclusion, surfactant replacement therapy cannot prevent poor outcome after prolonged warm ischaemia of 7 h in this model. While the beneficial effects of surfactant replacement therapy have been observed in several experimental and clinical studies related to heart-beating donor lungs and cold ischaemia, it is unlikely that surfactant replacement therapy will overcome the shortage of organs in the context of prolonged warm ischaemia, for example, 7 h. Moreover, our data demonstrate that right heart function and dysfunctions of the pulmonary vascular bed

  18. Results of beating heart mitral valve surgery via the trans-septal approach Resultados da abordagem transeptal para a valva mitral com coração batendo

    Directory of Open Access Journals (Sweden)

    Tomas A Salerno

    2009-03-01

    Full Text Available OBJECTIVE: Mitral valve surgery can be performed through the trans-atrial or the trans-septal approach. Although the trans-atrial is the preferred method, the trans-septal approach has also been used recently and has a particular value in beating-heart mitral valve surgery. Herein we report our experience with beating-heart mitral valve surgery via trans-septal approach, and discuss its advantages and pitfalls. METHODS: Between 2000 and 2007, 214 consecutive patients were operated upon utilizing beating heart technique for mitral valve surgery. The operation was performed via transseptal approach with the aorta unclamped, the heart beating, with normal electrocardiogram and in sinus rhythm. RESULTS: Mean age was 56.03 ± 13.93 years (range: 19-86 years; median: 56 years. There were 131 (61.2% males and 83 (38.8% females. Of the prostheses used, 108 (50.5% were biological, and 39 (18.2% were mechanical. Mitral repairs were performed in 67 (31.3% patients. Mean hospital stay was 17.4 ± 20.0 days (range: 3-135 days; median: 11 days. Intra-aortic balloon pump (IABP utilization was required in 12 (5.6% of 214 patients. One-month mortality was 7.4%, and re-operation for bleeding was needed in 15 (7% patients. CONCLUSIONS: Beating-heart mitral valve surgery is an option for myocardial protection in patients undergoing mitral valve surgery. This technique is facilitated by the trans-septal approach due to reduced aortic insufficiency and improved visualization of the mitral apparatus.OBJETIVO: A cirurgia da valva mitral pode ser feita via transatrial ou transeptal. Embora a transatrial seja a preferida, a via transeptal tem sido utilizada mais recentemente e tido um grande valor nas operações com o coração batendo. Mostramos a nossa experiência na cirurgia da valva mitral via transeptal com coração batendo e discutimos seus benefícios e problemas. MÉTODOS: Entre 2000 e 2007, 214 pacientes consecutivos foram operados com o coração batendo. A

  19. Beat-to-beat QT dynamics in healthy subjects

    DEFF Research Database (Denmark)

    Jensen, Berit T; Larroude, Charlotte E; Rasmussen, Lars P

    2004-01-01

    BACKGROUND: Measures of QT dynamics express repolarization abnormalities that carry prognostic information, but the reproducibility of beat-to-beat QT dynamics has never been established. The QT interval is prolonged at night, but how the circadian rhythm and heart rate influence the dynamic QT...... measurements is still unsettled. The aims of the present study were: (1) to describe the reproducibility of beat-to-beat QT dynamics with respect to intrasubject, between-subject, and between-observer variability and (2) to describe the normal range, circadian variation, and heart rate dependence of QT...... dynamics. METHODS: Ambulatory Holter recordings were performed three times on 20 healthy volunteers and were analyzed by two experienced cardiologists. Slope and intercept of the QT/RR regression, the variability of QT and R-R intervals expressed as the standard deviation, and the relation between QT...

  20. Healthy Dietary Fats Help Beat High Cholesterol

    Science.gov (United States)

    ... 166625.html Healthy Dietary Fats Help Beat High Cholesterol Eating them can reduce your risk of heart ... ones found in some vegetable oils can reduce cholesterol levels and heart disease risk as much as ...

  1. Efficacy of a novel bipolar radiofrequency ablation device on the beating heart for atrial fibrillation ablation: a long-term porcine study.

    Science.gov (United States)

    Voeller, Rochus K; Zierer, Andreas; Lall, Shelly C; Sakamoto, Shun-ichiro; Schuessler, Richard B; Damiano, Ralph J

    2010-07-01

    Over recent years, a variety of energy sources have been used to replace the traditional incisions of the Cox maze procedure for the surgical treatment of atrial fibrillation. This study evaluated the safety and efficacy of a new bipolar radiofrequency ablation device for atrial ablation in a long-term porcine model. Six pigs underwent a Cox maze IV procedure on a beating heart off cardiopulmonary bypass using the AtriCure Isolator II bipolar ablation device (AtriCure, Inc, Cincinnati, Ohio). In addition, 6 pigs underwent median sternotomy and pericardiotomy alone to serve as a control group. All animals were allowed to survive for 30 days. Each pig underwent induction of atrial fibrillation and was then humanely killed to remove the heart en bloc for histologic assessment. Magnetic resonance imaging scans were also obtained preoperatively and postoperatively to assess atrial and ventricular function, pulmonary vein anatomy, valve function, and coronary artery patency. All animals survived the operation. Electrical isolation of the left atrial appendage and the pulmonary veins was documented by pacing acutely and at 30 days in all animals. No animal that underwent the Cox maze IV procedure was able to be induced into atrial fibrillation at 30 days postoperatively, compared with all the sham animals. All 257 ablations examined were discrete, linear, and transmural, with a mean lesion width of 2.2 +/- 1.1 mm and a mean lesion depth of 5.3 +/- 3.0 mm. The AtriCure Isolator II device was able to create reliable long-term transmural lesions of the modified Cox maze procedure on a beating heart without cardiopulmonary bypass 100% of the time. There were no discernible effects on ventricular or valvular function. 2010 The American Association for Thoracic Surgery. Published by Mosby, Inc. All rights reserved.

  2. Efficacy and safety of right and left atrial ablations on the beating heart with irrigated bipolar radiofrequency energy: a long-term animal study.

    Science.gov (United States)

    Melby, Spencer J; Gaynor, Sydney L; Lubahn, Jordon G; Lee, Anson M; Rahgozar, Paymon; Caruthers, Shelton D; Williams, Todd A; Schuessler, Richard B; Damiano, Ralph J

    2006-10-01

    The Cox maze procedure is the most effective surgical treatment for atrial fibrillation; however, its complexity has limited its clinical utility. The purpose of this study was to simplify the procedure by using an irrigated bipolar radiofrequency ablation device on the beating heart without cardiopulmonary bypass. Six domestic pigs underwent median sternotomy. The pulmonary veins were circumferentially ablated. Electrical isolation was confirmed by pacing. Eight lesions were performed epicardially, and three lesions were performed through purse-string sutures with one of the jaws of the device introduced into the right atrium. After 30 days, magnetic resonance imaging was performed to assess atrial function, pulmonary vein anatomy, and coronary artery patency. Cholinergic stimulation and burst pacing were administered to induce atrial fibrillation. Histologic assessment of the heart was performed after the animal was killed. A modified Cox maze procedure was successfully performed with the irrigated bipolar radiofrequency device with no deaths. In every instance, the pulmonary veins were electrically isolated. Cholinergic stimulation with burst pacing failed to produce atrial fibrillation. Imaging studies revealed tricuspid regurgitation without evidence of pulmonary vein stenosis, coronary artery stenosis, or intra-atrial thrombus. Total atrial ejection fraction was 16.9% +/- 7.5%, a significant reduction. Histologically, 99% of the lesions were transmural, and there was no evidence of coronary sinus injury. Lesions on both the right and left atria can be created successfully on the beating heart with irrigated bipolar radiofrequency. The great majority of lesions with this device were transmural. This device should not be used on valvular tissue.

  3. Induction of chagasic-like arrhythmias in the isolated beating hearts of healthy rats perfused with Trypanosoma cruzi-conditioned medium

    Directory of Open Access Journals (Sweden)

    H. Rodriguez-Angulo

    2013-01-01

    Full Text Available Chagas' myocardiopathy, caused by the intracellular protozoan Trypanosoma cruzi, is characterized by microvascular alterations, heart failure and arrhythmias. Ischemia and arrythmogenesis have been attributed to proteins shed by the parasite, although this has not been fully demonstrated. The aim of the present investigation was to study the effect of substances shed by T. cruzi on ischemia/reperfusion-induced arrhythmias. We performed a triple ischemia-reperfusion (I/R protocol whereby the isolated beating rat hearts were perfused with either Vero-control or Vero T. cruzi-infected conditioned medium during the different stages of ischemia and subsequently reperfused with Tyrode's solution. ECG and heart rate were recorded during the entire experiment. We observed that triple I/R-induced bradycardia was associated with the generation of auricular-ventricular blockade during ischemia and non-sustained nodal and ventricular tachycardia during reperfusion. Interestingly, perfusion with Vero-infected medium produced a delay in the reperfusion-induced recovery of heart rate, increased the frequency of tachycardic events and induced ventricular fibrillation. These results suggest that the presence of parasite-shed substances in conditioned media enhances the arrhythmogenic effects that occur during the I/R protocol.

  4. A beating heart cell model to predict cardiotoxicity: effects of the dietary supplement ingredients higenamine, phenylethylamine, ephedrine and caffeine.

    Science.gov (United States)

    Calvert, Richard; Vohra, Sanah; Ferguson, Martine; Wiesenfeld, Paddy

    2015-04-01

    Some dietary supplements may contain cardiac stimulants and potential cardiotoxins. In vitro studies may identify ingredients of concern. A beating human cardiomyocyte cell line was used to evaluate cellular effects following phenylethylamine (PEA), higenamine, ephedrine or caffeine treatment. PEA and higenamine exposure levels simulated published blood levels in humans or animals after intravenous administration. Ephedrine and caffeine levels approximated published blood levels following human oral intake. At low or midrange levels, each chemical was examined plus or minus 50 µM caffeine, simulating human blood levels reported after consumption of caffeine-enriched dietary supplements. To measure beats per minute (BPM), peak width, etc., rhythmic rise and fall in intracellular calcium levels following 30 min of treatment was examined. Higenamine 31.3 ng/ml or 313 ng/ml significantly increased BPM in an escalating manner. PEA increased BPM at 0.8 and 8 µg/ml, while 80 µg/ml PEA reduced BPM and widened peaks. Ephedrine produced a significant BPM dose response from 0.5 to 5.0 µM. Caffeine increased BPM only at a toxic level of 250 µM. Adding caffeine to PEA or higenamine but not ephedrine further increased BPM. These in vitro results suggest that additional testing may be warranted in vivo to further evaluate these effects. Published by Elsevier Ltd.

  5. Heart beats in the cloud: distributed analysis of electrophysiological 'Big Data' using cloud computing for epilepsy clinical research.

    Science.gov (United States)

    Sahoo, Satya S; Jayapandian, Catherine; Garg, Gaurav; Kaffashi, Farhad; Chung, Stephanie; Bozorgi, Alireza; Chen, Chien-Hun; Loparo, Kenneth; Lhatoo, Samden D; Zhang, Guo-Qiang

    2014-01-01

    The rapidly growing volume of multimodal electrophysiological signal data is playing a critical role in patient care and clinical research across multiple disease domains, such as epilepsy and sleep medicine. To facilitate secondary use of these data, there is an urgent need to develop novel algorithms and informatics approaches using new cloud computing technologies as well as ontologies for collaborative multicenter studies. We present the Cloudwave platform, which (a) defines parallelized algorithms for computing cardiac measures using the MapReduce parallel programming framework, (b) supports real-time interaction with large volumes of electrophysiological signals, and (c) features signal visualization and querying functionalities using an ontology-driven web-based interface. Cloudwave is currently used in the multicenter National Institute of Neurological Diseases and Stroke (NINDS)-funded Prevention and Risk Identification of SUDEP (sudden unexplained death in epilepsy) Mortality (PRISM) project to identify risk factors for sudden death in epilepsy. Comparative evaluations of Cloudwave with traditional desktop approaches to compute cardiac measures (eg, QRS complexes, RR intervals, and instantaneous heart rate) on epilepsy patient data show one order of magnitude improvement for single-channel ECG data and 20 times improvement for four-channel ECG data. This enables Cloudwave to support real-time user interaction with signal data, which is semantically annotated with a novel epilepsy and seizure ontology. Data privacy is a critical issue in using cloud infrastructure, and cloud platforms, such as Amazon Web Services, offer features to support Health Insurance Portability and Accountability Act standards. The Cloudwave platform is a new approach to leverage of large-scale electrophysiological data for advancing multicenter clinical research.

  6. Beat Dreams?

    DEFF Research Database (Denmark)

    Sørensen, Bent

    2009-01-01

    Two of the founding members of the Beat Generation of the 1950s wrote dream books with almost identical titles: Jack Kerouac's Book of Dreams (1961) and William Burroughs' My Education: A Book of Dreams (1995). This paper queries the function of such dream books, both from a perspective of seeing...... dream writing as a confessional genre, and from the perspective of didacticism implicit in sharing one's dream life with one's readers. What role does memory, politics, fantasies and reality play in communicating with and via dreams?...

  7. Effects of the triazolopyrimidine trapidil on force of contraction, beating frequency and phosphodiesterase I--IV activity in guinea-pig hearts.

    Science.gov (United States)

    Bethke, T; Mehl, H; Meyer, W; Schmitz, W; Scholz, H; Thomas, K; Wenzlaff, H

    1991-05-01

    The effects of the triazolopyrimidine trapidil (5-methyl-7-diethylamino-s-triazolo [1,5-alpha]pyrimidine, CAS 15421-84-8) on force of contraction, beating frequency and phosphodiesterase (PDE) activity were investigated in isolated preparations from guinea-pig hearts. The effects of 3-isobutyl-1-methylxanthine (IBMX), theophylline and milrinone were studied for comparison. Trapidil exerted a concentration-dependent (1000-3000 mumol(s)/l) positive inotropic effect (EC50 562.4 mumol(s)/l) in guinea-pig papillary muscles. The positive inotropic effect was accompanied by a shortening of the duration of contraction as described for IBMX, or isoprenaline. The efficacy of trapidil was lower than that of IBMX or milrinone. Both agents maximally enhanced force of contraction to a 3fold (milrinone) or even 6fold greater amount (IBMX). The potency of trapidil was almost in the same order of magnitude as that of milrinone. The positive inotropic effect of trapidil is at least partially due to a cyclic adenosine monophosphate (cAMP)-dependent mechanism because carbachol antagonized the increase in force of contraction. Trapidil concentration-dependently but nonselectively inhibited the activities of cAMP PDE isoenzymes I-IV as did theophylline or IBMX. Based on IC50 values (275 mumol(s)/l on the average) trapidil had a potency similar to that of theophylline while IBMX was about one order of magnitude more potent. Regarding the inhibition of PDE III, IBMX was 49fold and milrinone 114fold more potent than trapidil. Trapidil revealed only a marginal positive chronotropic effect. The frequency of spontaneously beating right auricles was increased by 13% at most. Trapidil did not produce any tachyarrhythmias or contractures. It is concluded that the positive inotropic effect of trapidil is mainly due to PDE inhibition.(ABSTRACT TRUNCATED AT 250 WORDS)

  8. A System for 3D Ultrasound-Guided Robotic Retrieval of Foreign Bodies from a Beating Heart

    NARCIS (Netherlands)

    Thienphrapa, P.; Ramachandran, B.; Taylor, R.H.T.; Popovic, A.

    2012-01-01

    By way of the venous system or direct penetration, particles such asthrombi, bullet fragments, and shrapnel can become trapped in the heart and disrupt cardiac function. The severity of disruption can range from asymptomatic to fatal. Injuries of this nature are common in both civilian and military

  9. Intra-Aortic Balloon Pump Support in the Isolated Beating Porcine Heart in Nonischemic and Ischemic Pump Failure.

    Science.gov (United States)

    Schampaert, Stéphanie; van Nunen, Lokien X; Pijls, Nico H J; Rutten, Marcel C M; van Tuijl, Sjoerd; van de Vosse, Frans N; van 't Veer, Marcel

    2015-11-01

    The blood pressure changes induced by the intra-aortic balloon pump (IABP) are expected to create clinical improvement in terms of coronary perfusion and myocardial oxygen consumption. However, the measured effects reported in literature are inconsistent. The aim of this study was to investigate the influence of ischemia on IABP efficacy in healthy hearts and in shock. Twelve slaughterhouse porcine hearts (hearts 1-12) were connected to an external circulatory system, while physiologic cardiac performance was restored. Different clinical scenarios, ranging from healthy to cardiogenic shock, were simulated by step-wise administration of negative inotropic drugs. In hearts 7-12, severe global myocardial ischemia superimposed upon the decreased contractile states was created. IABP support was applied in all hearts under all conditions. Without ischemia, the IABP induced a mild increase in coronary blood flow and cardiac output. These effects were strongly augmented in the presence of persisting ischemia, where coronary blood flow increased by 49 ± 24% (P < 0.01) and cardiac output by 17 ± 6% (P < 0.01) in case of severe pump failure. As expected, myocardial oxygen consumption increased in case of ischemia (21 ± 17%; P < 0.01), while it slightly decreased without (-3 ± 6%; P < 0.01). In case of progressive pump failure due to persistent myocardial ischemia, the IABP increased hyperemic coronary blood flow and cardiac output significantly, and reversed the progressive hemodynamic deterioration within minutes. This suggests that IABP therapy in acute myocardial infarction is most effective in patients with viable myocardium, suffering from persistent myocardial ischemia, despite adequate epicardial reperfusion. Copyright © 2015 International Center for Artificial Organs and Transplantation and Wiley Periodicals, Inc.

  10. Assessment of left-atrial strain parameters in patients with frequent ventricular ectopic beats without structural heart disease.

    Science.gov (United States)

    Barutçu, Ahmet; Gazi, Emine; Temiz, Ahmet; Bekler, Adem; Altun, Burak; Kırılmaz, Bahadır; Küçük, Uğur

    2014-08-01

    Ventricular ectopic beats (VEBs) are often encountered in daily clinical practice. Clinical significance of VEBs seen in patients without structural cardiovascular diseases is controversial. We aimed to investigate the effects of VEBs on left atrium (LA) function using speckle tracking echocardiography with LA strain parameters. Patients with frequent VEBs (more than 30 times in 1 h, according to the Lown classification) were identified. Identified patients were evaluated by speckle tracking methods. There were 40 patients with frequent VEBs and 40 controls in our study. The general characteristics were similar of the study population. The LA global longitudinal strain parameters were significantly different. Global Peak atrial longitudinal strain (PALS) (38.39 ± 7.93 vs. 44.15 ± 6.71, p = 0.001) and peak atrial contraction strain (PACS) (16.37 ± 4.58 vs. 20.49 ± 3.65, p = 0.000) were revealed significantly lower in the VEBs group. Time to peak longitudinal strain (TPLS) was found significantly longer in the VEBs group [485.5 (352-641) vs. 435 (339-516.5) p = 0.000]. Number of VEBS was correlated with TPLS (r = 0.499, p = 0.000). PALS and PACS were negatively correlated with number of VEBs (r = -0.348, p = 0.002 and r = -0.444, p = 0.000, respectively). We described that in this study, The LA functions are affected by VEBs adversely. This deterioration is increasing as the number of VEBs.

  11. Problems of rapid digitalization in severe congestive heart failure.

    Science.gov (United States)

    Haustein, K O; Assmann, I; Fiehring, H

    1980-02-01

    The pharmacodynamic effects (changes of systolic time intervals, STI, reaction of pulmonary arterial pressure) of digitoxin were studied in 7 patients with severe congestive heart failure in comparison with the corresponding plasma level. STI indicated glycoside-dependent changes, i.e. shortening of LVETc and QS2c and normalization of prolonged PEPc, while ICT shortening was less observed. In 2 patients with cor pulmonale a pulmonary oedema occurred accompanied with prolonged LVETc. During the early period of glycoside-dependent recompensation no significant correlation between STI shortening and glycoside plasma level was observed. Because of the retarded normalization of the haemodynamics of the pulmonary circulation and because of possible side-effects, rapid digitalization has to be reconsidered.

  12. Beating Depression …Help Is Available

    Science.gov (United States)

    ... Navigation Bar Home Current Issue Past Issues Beating Depression …Help Is Available Past Issues / Summer 2007 Table ... treatments are available from your physician. Types of Depression Just like other illnesses, such as heart disease, ...

  13. Subnormothermic machine perfusion for non-heart-beating donor liver grafts preservation in a Swine model: a new strategy to increase the donor pool?

    Science.gov (United States)

    Gringeri, E; Bonsignore, P; Bassi, D; D'Amico, F E; Mescoli, C; Polacco, M; Buggio, M; Luisetto, R; Boetto, R; Noaro, G; Ferrigno, A; Boncompagni, E; Freitas, I; Vairetti, M P; Carraro, A; Neri, D; Cillo, U

    2012-09-01

    We previously reported that subnormothermic machine perfusion (sMP; 20°C) is able to improve the preservation of livers obtained from non-heart-beating donors (NHBDs) in rats. We have compared sMP and standard cold storage (CS) to preserve pig livers after 60 minutes of cardiac arrest. In the sMP group livers were perfused for 6 hours with Celsior at 20°C. In the CS group they were stored in Celsior at 4°C for 6 hours as usual. To simulate liver transplantation, both sMP- and CS-preserved livers were reperfused using a mechanical continuous perfusion system with autologus blood for 2 hours at 37°C. At 120 min after reperfusion aspartate aminotransferase levels in sMP versus CS were 499 ± 198 versus 7648 ± 2806 U/L (P < .01); lactate dehydrogenase 1685 ± 418 versus 12998 ± 3039 U/L (P < .01); and lactic acid 4.78 ± 3.02 versus 10.46 ± 1.79 mmol/L (P < .01) respectively. The sMP group showed better histopathologic results with significantly less hepatic damage. This study confirmed that sMP was able to resuscitate liver grafts from large NHBD animals. Copyright © 2012 Elsevier Inc. All rights reserved.

  14. Comparison of Polar® RS800CX heart rate monitor and electrocardiogram for measuring inter-beat intervals in healthy dogs.

    Science.gov (United States)

    Essner, Ann; Sjöström, Rita; Ahlgren, Erik; Gustås, Pia; Edge-Hughes, Laurie; Zetterberg, Lena; Hellström, Karin

    2015-01-01

    The aim of the present study was to assess the criterion validity, relative reliability and level of agreement of Polar® RS800CX heart rate monitor measuring inter-beat intervals (IBIs), compared to simultaneously recorded electrocardiogram (ECG) in dogs. Five continuous minutes of simultaneously recorded IBIs from Polar® RS800CX and Cardiostore ECG in 11 adult healthy dogs maintaining standing position were analyzed. Polar® data was statistically compared to ECG data to assess for systematic differences between the methods. Three different methods for handling missing IBI data were used. Criterion validities were calculated by intraclass correlation coefficients (ICCs) and corresponding 95% confidence intervals (CIs). Relative reliabilities and levels of agreement were calculated by ICCs and the Bland and Altman analysis for repeated measurements per subject. Correlation coefficients between IBI data from ECG and Polar® RS800CX varied between 0.73 and 0.84 depending on how missing values were handled. Polar® was over- and underestimating IBI data compared to ECG. The mean difference in log transformed (base10) IBI data was 0.8%, and 93.2% of the values were within the limits of agreement. Internally excluding three subjects presenting IBI series containing more than 5% erroneous IBIs resulted in ICCs between 0.97 and 0.99. Bland and Altman analysis (n=8) showed mean difference was 1.8ms, and 98.5% of the IBI values were plotted inside limits of agreement. This study showed that Polar® systematically biased recorded IBI series and that it was fundamental to detect measurement errors. For Polar® RS800CX heart rate monitor to be used interchangeably to ECG, by showing excellent criterion validity and reliable IBI measures in group and individual samples, only less than 5% of artifacts could be accepted. Copyright © 2014 Elsevier Inc. All rights reserved.

  15. Rapid Speed Modulation of a Rotary Total Artificial Heart Impeller.

    Science.gov (United States)

    Kleinheyer, Matthias; Timms, Daniel L; Tansley, Geoffrey D; Nestler, Frank; Greatrex, Nicholas A; Frazier, O Howard; Cohn, William E

    2016-09-01

    Unlike the earlier reciprocating volume displacement-type pumps, rotary blood pumps (RBPs) typically operate at a constant rotational speed and produce continuous outflow. When RBP technology is used in constructing a total artificial heart (TAH), the pressure waveform that the TAH produces is flat, without the rise and fall associated with a normal arterial pulse. Several studies have suggested that pulseless circulation may impair microcirculatory perfusion and the autoregulatory response and may contribute to adverse events such as gastrointestinal bleeding, arteriovenous malformations, and pump thrombosis. It may therefore be beneficial to attempt to reproduce pulsatile output, similar to that generated by the native heart, by rapidly modulating the speed of an RBP impeller. The choice of an appropriate speed profile and control strategy to generate physiologic waveforms while minimizing power consumption and blood trauma becomes a challenge. In this study, pump operation modes with six different speed profiles using the BiVACOR TAH were evaluated in vitro. These modes were compared with respect to: hemodynamic pulsatility, which was quantified as surplus hemodynamic energy (SHE); maximum rate of change of pressure (dP/dt); pulse power index; and motor power consumption as a function of pulse pressure. The results showed that the evaluated variables underwent different trends in response to changes in the speed profile shape. The findings indicated a possible trade-off between SHE levels and flow rate pulsatility related to the relative systolic duration in the speed profile. Furthermore, none of the evaluated measures was sufficient to fully characterize hemodynamic pulsatility. © 2016 International Center for Artificial Organs and Transplantation and Wiley Periodicals, Inc.

  16. Proarrhythmic electrical remodelling is associated with increased beat-to-beat variability of repolarisation

    DEFF Research Database (Denmark)

    Thomsen, Morten Bækgaard; Oros, Avram; Schoenmakers, Marieke

    2007-01-01

    Acquired long-QT syndrome in combination with increased beat-to-beat variability of repolarisation duration (BVR) is associated with lethal torsades de pointes arrhythmias (TdP) in dogs with remodelled heart after atrioventricular block (AVB). We evaluated the relative contributions of bradycardi...

  17. Associations of BMI and its fat-free and fat components with blood lipids in children: Project HeartBeat!

    Science.gov (United States)

    Dai, Shifan; Eissa, Mona A; Steffen, Lyn M; Fulton, Janet E; Harrist, Ronald B; Labarthe, Darwin R

    2011-04-01

    AIM: This study aimed to distinguish between the roles of the two components of BMI, the fat mass (FM) index and the fat-free mass (FFM) index, in BMI's association with blood lipids in children and adolescents. METHODS: A total of 678 children (49.1% female, 79.9% non-black), initially aged 8, 11 and 14 years, were followed at 4-month intervals for up to 4 years (1991-1995). Total cholesterol (TC), LDL-C, HDL-C and triglycerides were determined in fasting blood samples. FFM index and FM index were calculated as FFM (kg)/height (m)(2) and FM (kg)/height (m)(2), respectively. Using a multilevel linear model, repeated measurements of blood lipids were regressed on concurrent measures of BMI or its components, adjusting for age, sex and race and, in a subsample, also for physical activity, energy intake and sexual maturity. RESULTS: Estimated regression coefficients for the relations of TC with BMI, FFM index and FM index were 1.539, -0.606 (p > 0.05) and 3.649, respectively. When FFM index and FM index were entered into the TC model simultaneously, regression coefficients were -0.855 and 3.743, respectively. An increase in BMI was related to an increase in TC; however, an equivalent increase in FM index was related to a greater increase in TC and, when FFM index was tested alone or with FM index, an increase in FFM index was related to a decrease in TC. Similar results were observed for LDL-C. FFM index and FM index were both inversely related to HDL-C and directly to triglycerides. Compared with FFM index, the equivalent increase in FM index showed a greater decrease in HDL-C. CONCLUSION: Greater BMI was related to adverse levels of blood lipids in children and adolescents, which was mainly attributable to BMI's fat component. It is important to identify weight management strategies to halt the childhood obesity epidemic and subsequently prevent heart disease in adulthood.

  18. The effect of perfusion prior to cold preservation and addition of biliverdin on the liver graft from non-heart-beating donors.

    Science.gov (United States)

    Iwane, T; Akamatsu, Y; Narita, T; Nakamura, A; Satomi, S

    2006-12-01

    Our aim was to improve the energy status and viability of a liver graft from a non-heart-beating donor (NHBD), we investigated the effects of perfusion prior to cold preservation and the addition of an antioxidant, biliverdin. Rats were divided into five groups: group 1: without 30 minutes warm ischemia (WI) and cold preservation (control group); group 2 without WI and with 6 hours of cold preservation in UW solution (HBD group); group 3 with WI and cold preservation (NHBD group); group 4 with 30 minutes perfusion prior to cold preservation (PRE group); and group 5 with addition of biliverdin to precold preservation perfusion (BV group). Oxygenated Klebs-Henseleit solution was used as the perfusate prior to and after preservation. Portal flow and bile production during reperfusion, energy charge (EC), ATP level, GOT, and TNF-alpha were measured as well as a histological evaluation. Portal flow of the PRE and BV groups during 1 hour of reperfusion was higher than of that the NHBD group. Bile production of the PRE group was also higher than that of the NHBD group, but bile production in the BV group was comparable to the NHBD group. EC of the PRE group was higher than that of the NHBD group prior to and after reperfusion. The EC and ATP levels of the BV group after reperfusion were higher than those of the NHBD and PRE groups. The GOT and TNF-alpha were reduced in the BV group. Precold preservation perfusion improves the viability of grafts from NHBDs. Furthermore, biliverdin exerted an additive effect to ameliorate energy status.

  19. Determination of aortic valve opening time and left ventricular peak filling rate from the peripheral pulse amplitude in patients with ectopic beats.

    Science.gov (United States)

    Zheng, Dingchang; Allen, John; Murray, Alan

    2008-12-01

    Ectopic beats are common in patients who have heart disease and are associated with reduced peripheral pulse amplitude. This study determined the start of the peripheral pulse increase and from it the opening of the aortic valve. The left ventricular peak filling rate was also estimated from the peripheral pulse. Results were compared with published invasive and cardiac imaging data. Twenty-five subjects with ectopic beat electrocardiograms (ECGs) were studied. The ECGs and the peripheral pulses, detected optically at the right index finger by a simple photoplethysmography (PPG) technique, were recorded for subsequent analysis. Peripheral pulse amplitudes for ectopic beats, post-ectopic sinus beats and normal sinus beats were determined. Ectopic beats induced a mean 68% decrease in pulse amplitude in comparison with sinus beats (p ectopic sinus beats increased by 20% (p ectopic beats and post-ectopic sinus beats. The range of shortest coupling interval (CI) for ectopic beats with observable pulses was from 373 to 531 ms, with the mean value equivalent to 55% of the mean sinus RR interval, comparable with the opening of the aortic valve. Finally, as the CI increased, the pulse amplitude increased quickly from zero. The average rate of increase was equivalent to 4.8 times the normal sinus amplitude in 1 s, equal to 50% filling in 208 ms, showing diastolic rapid filling, comparable with published left ventricular peak filling rate data. In conclusion, the effect of ectopic beat CI on peripheral pulse amplitude has been determined, providing useful information for developing a technique to determine the opening of the aortic valve and the peak filling rate non-invasively and peripherally in patients with frequent ectopic beats.

  20. Do nonlinearities play a significant role in short term, beat-to-beat variability?

    Science.gov (United States)

    Choi, H. G.; Mukkamala, R.; Moody, G. B.; Mark, R. G.

    2001-01-01

    Numerous studies of short-term beat-to-beat variability in cardiovascular signals have not resolved the debate about the completeness of linear analysis techniques. This aim of this paper is to evaluate further the role of nonlinearities in short-term, beat-to-beat variability. We compared linear autoregressive moving average (ARMA) and nonlinear neural network (NN) models for predicting instantaneous heart rate (HR) and mean arterial blood pressure (BP) from past HR and BP. To evaluate these models, we used HR and BP time series from the MIMIC database. Experimental results indicate that NN-based nonlinearities do not play a significant role and suggest that ARMA linear analysis techniques provide adequate characterization of the system dynamics responsible for generating short-term, beat-to-beat variability.

  1. The Rapidly Evolving Concept of Whole Heart Engineering

    Directory of Open Access Journals (Sweden)

    Laura Iop

    2017-01-01

    Full Text Available Whole heart engineering represents an incredible journey with as final destination the challenging aim to solve end-stage cardiac failure with a biocompatible and living organ equivalent. Its evolution started in 2008 with rodent organs and is nowadays moving closer to clinical application thanks to scaling-up strategies to human hearts. This review will offer a comprehensive examination on the important stages to be reached for the bioengineering of the whole heart, by describing the approaches of organ decellularization, repopulation, and maturation so far applied and the novel technologies of potential interest. In addition, it will carefully address important demands that still need to be satisfied in order to move to a real clinical translation of the whole bioengineering heart concept.

  2. Alteration of LV end-diastolic volume by controlling the power of the continuous-flow LVAD, so it is synchronized with cardiac beat: development of a native heart load control system (NHLCS).

    Science.gov (United States)

    Umeki, Akihide; Nishimura, Takashi; Ando, Masahiko; Takewa, Yoshiaki; Yamazaki, Kenji; Kyo, Shunei; Ono, Minoru; Tsukiya, Tomonori; Mizuno, Toshihide; Taenaka, Yoshiyuki; Tatsumi, Eisuke

    2012-06-01

    There are many reports comparing pulsatile and continuous-flow left ventricular assist devices (LVAD). But continuous-flow LVAD with the pulsatile driving technique had not been tried or discussed before our group's report. We have previously developed and introduced a power-control unit for a centrifugal LVAD (EVAHEART®; Sun Medical), which can change the speed of rotation so it is synchronized with the heart beat. By use of this unit we analyzed the end-diastolic volume (EDV) to determine whether it is possible to change the native heart load. We studied 5 goats with normal hearts and 5 goats with acute LV dysfunction because of micro-embolization of the coronary artery. We used 4 modes, "circuit-clamp", "continuous", "counter-pulse", and "co-pulse", with the bypass rate (BR) 100%. We raised the speed of rotation of the LVAD in the diastolic phase with the counter-pulse mode, and raised it in the systolic phase with the co-pulse mode. As a result, the EDV decreased in the counter-pulse mode and increased in the co-pulse mode, compared with the continuous mode (p < 0.05), in both the normal and acute-heart-failure models. This result means it may be possible to achieve favorable EDV and native heart load by controlling the rotation of continuous-flow LVAD, so it is synchronized with the cardiac beat. This novel driving system may be of great benefit to patients with end-stage heart failure, especially those with ischemic etiology.

  3. Beat-to-Beat Blood Pressure Monitor

    Science.gov (United States)

    Lee, Yong Jin

    2012-01-01

    This device provides non-invasive beat-to-beat blood pressure measurements and can be worn over the upper arm for prolonged durations. Phase and waveform analyses are performed on filtered proximal and distal photoplethysmographic (PPG) waveforms obtained from the brachial artery. The phase analysis is used primarily for the computation of the mean arterial pressure, while the waveform analysis is used primarily to obtain the pulse pressure. Real-time compliance estimate is used to refine both the mean arterial and pulse pressures to provide the beat-to-beat blood pressure measurement. This wearable physiological monitor can be used to continuously observe the beat-to-beat blood pressure (B3P). It can be used to monitor the effect of prolonged exposures to reduced gravitational environments and the effectiveness of various countermeasures. A number of researchers have used pulse wave velocity (PWV) of blood in the arteries to infer the beat-to-beat blood pressure. There has been documentation of relative success, but a device that is able to provide the required accuracy and repeatability has not yet been developed. It has been demonstrated that an accurate and repeatable blood pressure measurement can be obtained by measuring the phase change (e.g., phase velocity), amplitude change, and distortion of the PPG waveforms along the brachial artery. The approach is based on comparing the full PPG waveform between two points along the artery rather than measuring the time-of-flight. Minimizing the measurement separation and confining the measurement area to a single, well-defined artery allows the waveform to retain the general shape between the two measurement points. This allows signal processing of waveforms to determine the phase and amplitude changes.

  4. Heart bypass surgery - discharge

    Science.gov (United States)

    Off-pump coronary artery bypass - discharge; OPCAB - discharge; Beating heart surgery - discharge; Bypass surgery - heart - discharge; CABG - discharge; Coronary artery bypass graft - discharge; Coronary artery ...

  5. The effects of inhaled nitric oxide, gabexate mesilate, and retrograde flush in the lung graft from non-heart beating minipig donors.

    Science.gov (United States)

    Luh, S P; Tsai, C C; Shau, W Y; Chen, J S; Kuo, S H; Lin-Shiau, S Y; Lee, Y C

    2000-05-27

    The use of lung grafts from non-heart-beating donors (NHBD) is one way of solving the donor organ shortage problem. In this experiment, we studied the effect of retrograde flush (RF) from the left atrium before harvest, inhaled nitric oxide (NO), and gabexate mesilate (FOY), a protease inhibitor, in the lung grafts from NHBD. Forty-eight Lee-Sung, small-ear, miniature pigs (15-20 kg) were divided into 24 pairs (donor and recipient) and four groups. The donor lungs were flushed and harvested 90 min after cardiac arrest. No i.v. heparin was administered until the time before flush and harvest. Left single lung transplantation was undertaken, and the recipients were observed for 18 hr. The grafts warm and cold ischemia times were 90 (controlled) and 183+/-23.4 min. Group 1 (untreated control, UC, n=6) had core perfusion through a Swan-Ganz catheter followed by a single, antegrade flush with modified Euro-Collin's solution containing heparin, urokinase, and PGE1. Group 2 (RF group, n=6) had the same as group 1, except that one additive retrograde flush through the left atrium was administered. Group 3 (NO group, n=6) had the same as group 1, except that 20 parts per million (ppm) inhaled NO was administered for the cadaver donors before the graft harvest, and for the recipients after the grafts reperfusion. Group 4 (FOY group, n=6) had the same as group 1, except that the recipients received FOY i.v. infusion from the beginning of the recipient's operation and continuously throughout the experiments. Compared with the group 1 (control), group 2 (RF) had significantly (Pinjury score, and higher PaO2/FiO2 and pulmonary dynamic compliance. Group 3 (NO) had significantly lower mean pulmonary arterial pressure, PVR, lung injury score, degree of tissue neutrophils infiltration (histological and myeloperoxidase assay), bronchoalveolar lavage fluid protein content and neutrophils (PMNs) percentage, and higher PaO2/FiO2 and pulmonary dynamic compliance. Group 4 (FOY) had

  6. Binaural beat salience

    Science.gov (United States)

    Grose, John H.; Buss, Emily; Hall, Joseph W.

    2012-01-01

    Previous studies of binaural beats have noted individual variability and response lability, but little attention has been paid to the salience of the binaural beat percept. The purpose of this study was to gauge the strength of the binaural beat percept by matching its salience to that of sinusoidal amplitude modulation (SAM), and to then compare rate discrimination for the two types of fluctuation. Rate discrimination was measured for standard rates of 4, 8, 16, and 32 Hz – all in the 500-Hz carrier region. Twelve normal-hearing adults participated in this study. The results indicated that discrimination acuity for binaural beats is similar to that for SAM tones whose depths of modulation have been adjusted to provide equivalent modulation salience. The matched-salience SAM tones had relatively shallow depths of modulation, suggesting that the perceptual strength of binaural beats is relatively weak, although all listeners perceived them. The Weber fraction for detection of an increase in binaural beat rate is roughly constant across beat rates, at least for rates above 4 Hz, as is rate discrimination for SAM tones. PMID:22326292

  7. Up-Beat UK: A programme of research into the relationship between coronary heart disease and depression in primary care patients

    Directory of Open Access Journals (Sweden)

    Pariante Carmine M

    2011-05-01

    Full Text Available Abstract Background Coronary heart disease and depression are both common health problems and by 2020 will be the two leading causes of disability worldwide. Depression has been found to be more common in patients with coronary heart disease but the nature of this relationship is uncertain. In the United Kingdom general practitioners are now being remunerated for case-finding for depression in patients with coronary heart disease, however it is unclear how general practitioners should manage these patients. We aim to explore the relationship between coronary heart disease and depression in a primary care population and to develop an intervention for patients with coronary heart disease and depression. Methods/design This programme of research will consist of 4 inter-related studies. A 4 year prospective cohort study of primary care patients with coronary heart disease will be conducted to explore the relationship between coronary heart disease and depression. Within this, a nested case-control biological study will investigate genetic and blood-biomarkers as predictors of depression in this sample. Two qualitative studies, one of patients' perspectives of treatments for coronary heart disease and co-morbid depression and one of primary care professionals' views on the management of patients with coronary heart disease and depression will inform the development of an intervention for this patient group. A feasibility study for a randomised controlled trial will then be conducted. Discussion This study will provide information on the relationship between coronary heart disease and depression that will allow health services to determine the efficiency of case-finding for depression in this patient group. The results of the cohort study will also provide information on risk factors for depression. The study will provide evidence on the efficacy and feasibility of a joint patient and professional led intervention and data necessary to plan a

  8. Up-beat UK: a programme of research into the relationship between coronary heart disease and depression in primary care patients.

    Science.gov (United States)

    Tylee, André; Ashworth, Mark; Barley, Elizabeth; Brown, June; Chambers, John; Farmer, Anne; Fortune, Zoe; Haddad, Mark; Lawton, Rebecca; Mann, Anthony; Mehay, Anita; McCrone, Paul; Murray, Joanna; Leese, Morven; Pariante, Carmine M; Rose, Diana; Rowlands, Gill; Smith, Alison; Walters, Paul

    2011-05-23

    Coronary heart disease and depression are both common health problems and by 2020 will be the two leading causes of disability worldwide. Depression has been found to be more common in patients with coronary heart disease but the nature of this relationship is uncertain. In the United Kingdom general practitioners are now being remunerated for case-finding for depression in patients with coronary heart disease, however it is unclear how general practitioners should manage these patients. We aim to explore the relationship between coronary heart disease and depression in a primary care population and to develop an intervention for patients with coronary heart disease and depression. This programme of research will consist of 4 inter-related studies. A 4 year prospective cohort study of primary care patients with coronary heart disease will be conducted to explore the relationship between coronary heart disease and depression. Within this, a nested case-control biological study will investigate genetic and blood-biomarkers as predictors of depression in this sample. Two qualitative studies, one of patients' perspectives of treatments for coronary heart disease and co-morbid depression and one of primary care professionals' views on the management of patients with coronary heart disease and depression will inform the development of an intervention for this patient group. A feasibility study for a randomised controlled trial will then be conducted. This study will provide information on the relationship between coronary heart disease and depression that will allow health services to determine the efficiency of case-finding for depression in this patient group. The results of the cohort study will also provide information on risk factors for depression. The study will provide evidence on the efficacy and feasibility of a joint patient and professional led intervention and data necessary to plan a definitive randomised controlled trial of the intervention.

  9. Data and Statistics: Heart Failure

    Science.gov (United States)

    ... High Blood Pressure Salt Cholesterol Million Hearts® WISEWOMAN Heart Failure Fact Sheet Recommend on Facebook Tweet Share Compartir ... not mean that the heart has stopped beating. Heart Failure in the United States About 5.7 million ...

  10. Binaural Beat: A Failure to Enhance EEG Power and Emotional Arousal

    Directory of Open Access Journals (Sweden)

    Fran López-Caballero

    2017-11-01

    Full Text Available When two pure tones of slightly different frequencies are delivered simultaneously to the two ears, is generated a beat whose frequency corresponds to the frequency difference between them. That beat is known as acoustic beat. If these two tones are presented one to each ear, they still produce the sensation of the same beat, although no physical combination of the tones occurs outside the auditory system. This phenomenon is called binaural beat. In the present study, we explored the potential contribution of binaural beats to the enhancement of specific electroencephalographic (EEG bands, as previous studies suggest the potential usefulness of binaural beats as a brainwave entrainment tool. Additionally, we analyzed the effects of binaural-beat stimulation on two psychophysiological measures related to emotional arousal: heart rate and skin conductance. Beats of five different frequencies (4.53 Hz -theta-, 8.97 Hz -alpha-, 17.93 Hz -beta-, 34.49 Hz -gamma- or 57.3 Hz -upper-gamma were presented binaurally and acoustically for epochs of 3 min (Beat epochs, preceded and followed by pink noise epochs of 90 s (Baseline and Post epochs, respectively. In each of these epochs, we analyzed the EEG spectral power, as well as calculated the heart rate and skin conductance response (SCR. For all the beat frequencies used for stimulation, no significant changes between Baseline and Beat epochs were observed within the corresponding EEG bands, neither with binaural or with acoustic beats. Additional analysis of spectral EEG topographies yielded negative results for the effect of binaural beats in the scalp distribution of EEG spectral power. In the psychophysiological measures, no changes in heart rate and skin conductance were observed for any of the beat frequencies presented. Our results do not support binaural-beat stimulation as a potential tool for the enhancement of EEG oscillatory activity, nor to induce changes in emotional arousal.

  11. Wearable Beat to Beat Blood Pressure Monitor Project

    Data.gov (United States)

    National Aeronautics and Space Administration — A key component of NASA's human exploration programs is a system that monitors the health of the crew during space missions. The wearable beat-to-beat blood pressure...

  12. Beating Breast Cancer

    Science.gov (United States)

    ... of this page please turn JavaScript on. Feature: Breast Cancer Beating Breast Cancer Past Issues / Winter 2017 Table of Contents Melanie ... Her mother had died at age 49 of breast cancer after three battles with the disease. Ovarian cancer ...

  13. Beat in der Kleinstadt

    OpenAIRE

    Spengler, Peter

    1994-01-01

    Beat in der Kleinstadt : "langhaarige Affen" oder Jugendkultur in d. 60er Jahren. - In: "Schön ist die Jugendzeit ...?" / hrsg. von Harald Parigger ... - Augsburg : Haus d. Bayer. Geschichte, 1994. - S. 81-85. - (Veröffentlichungen zur bayerischen Geschichte und Kultur ; 27)

  14. Europe’s Wild Heart – still beating? Experiences from a new transboundary wilderness area in the middle of the Old Continent

    Directory of Open Access Journals (Sweden)

    Zdenka Křenová

    2013-03-01

    Full Text Available The face of Europe has been shaped by human civilization for centuries and wilderness did not only vanish from the continent’s surface but also from humans’ minds and experiences. However, there are still a few places left, which have remained more or less unmodified and have at least the potential for rewilding. Among them are the Šumava National Park and the neighbouring Bavarian Forest NP, which together create a unique forest zone in the middle of Europe susceptible to host and demonstrate natural forest dynamics and ecosystem processes. This is also a large and very important Natura 2000 area. Transboundary cooperation between both National parks has improved since 1990, when the former Iron Curtain Corridor was opened, and culminated by the project Europe’s Wild Heart. The main goal of the project Europe’s Wild Heart, which started in 2008, was to develop a transboundary wilderness area in the core zones of the two national parks – BFNP and ŠNP. The project area was 13,060 ha and a “life story” of this project is described in this paper. A common “vision 2020” was signed where both parks committed among other things “to achieve a joint core area of about 15,000 ha with harmonized management principles, information services and monitoring networks to officially become the first and largest transboundary wilderness area in Central Europe”. Unfortunately, the bark beetle outbreak which followed the Kyrill hurricane in 2008 and 2009 escalated the discussion about appropriate forest management in the ŠNP. Opponents of the national park principles, non-intervention and wilderness concept became more and more vocal. The situation escalated after the election in 2010 when the Green Party was replaced by conservatives (ODS – Civic Democratic Party at the Czech Ministry of Environment. Clear cuttings were started in some former non-intervention parts of the ŠNP and hunting was again allowed in the core zone. Since then

  15. Prevalence and correlates of ventricular premature beats detected by ambulatory electrocardiography in working populations.

    Science.gov (United States)

    Green, M S; Jucha, E; Luz, J; Cocos, M; Nurynberg, M; Rosenberg, N

    1988-05-01

    The associations of ventricular premature beats detected on a one-hour ambulatory electrocardiogram with demographic, behavioral, physiologic, and anthropometric variables were examined in 2,331 factory workers aged 20-69 years. Ventricular premature beats were more prevalent with increasing age and with abnormal resting electrocardiograms. From the age of 40, they were more common among males than among females. An association with ethnicity was observed, ventricular premature beats being most common among Israelis of European origin. In univariate analysis, resting heart rate was inversely associated with the presence of ventricular premature beats for females only. Ambulatory heart rate was positively associated with ventricular premature beats only among males. No associations with smoking habits or relative weight were found. Among males and females with normal electrocardiograms, systolic and diastolic blood pressures were significant correlates of ventricular premature beats in univariate analysis and after controlling for age, resting and ambulatory heart rates, and ethnic origin.

  16. Ultrasound-Guided Transesophageal High-Intensity Focused Ultrasound Cardiac Ablation in a Beating Heart: A Pilot Feasibility Study in Pigs.

    Science.gov (United States)

    Bessiere, Francis; N'djin, W Apoutou; Colas, Elodie Constanciel; Chavrier, Françoise; Greillier, Paul; Chapelon, Jean Yves; Chevalier, Philippe; Lafon, Cyril

    2016-08-01

    Catheter ablation for the treatment of arrhythmia is associated with significant complications and often-repeated procedures. Consequently, a less invasive and more efficient technique is required. Because high-intensity focused ultrasound (HIFU) enables the generation of precise thermal ablations in deep-seated tissues without harming the tissues in the propagation path, it has the potential to be used as a new ablation technique. A system capable of delivering HIFU into the heart by a transesophageal route using ultrasound (US) imaging guidance was developed and tested in vivo in six male pigs. HIFU exposures were performed on atria and ventricles. At the time of autopsy, visual inspection identified thermal lesions in the targeted areas in three of the animals. These lesions were confirmed by histologic analysis (mean size: 5.5 mm(2) × 11 mm(2)). No esophageal thermal injury was observed. One animal presented with bradycardia due to an atrio-ventricular block, which provides real-time confirmation of an interaction between HIFU and the electrical circuits of the heart. Thus, US-guided HIFU has the potential to minimally invasively create myocardial lesions without an intra-cardiac device. Copyright © 2016 World Federation for Ultrasound in Medicine & Biology. Published by Elsevier Inc. All rights reserved.

  17. Endoscopic exposure and stabilization of posterior and inferior branches using the endo-starfish cardiac positioner and the endo-octopus stabilizer for closed-chest beating heart multivessel CABG: hemodynamic changes in the pig.

    Science.gov (United States)

    Gründeman, Paul F; Budde, Ricardo; Beck, Hendricus Mansvelt; van Boven, Wim-Jan; Borst, Cornelius

    2003-09-09

    RDP, and composite graft from left IMA jump to diagonal branch). In 10 animals, 16 successfully completed anastomoses to RPD and OM branches of Ø1.75 to 2.5 mm required 25 to 60 minutes each to construct. At sacrifice, all anastomoses were patent. In the closed-chest pig in Trendelenburg position and during lifting of the sternum, the EndoStarfish and EndoOctopus enabled IMA grafting of posterior and inferior branches on the beating heart without mean arterial pressure dropping below 70 mm Hg.

  18. Blood Pressure vs. Heart Rate

    Science.gov (United States)

    ... Venous Thromboembolism Aortic Aneurysm More Blood Pressure vs. Heart Rate (Pulse) Updated:Sep 15,2017 Understanding the difference ... your blood moving through your blood vessels, your heart rate is the number of times your heart beats ...

  19. Heart bypass surgery

    Science.gov (United States)

    Off-pump coronary artery bypass; OPCAB; Beating heart surgery; Bypass surgery - heart; CABG; Coronary artery bypass graft; Coronary artery bypass surgery; Coronary bypass surgery; Coronary artery disease - CABG; CAD - CABG; Angina - ...

  20. Heart rate response to breathing

    DEFF Research Database (Denmark)

    Mehlsen, J; Pagh, K; Nielsen, J S

    1987-01-01

    Heart rate responses to stepwise and periodic changes in lung volume were studied in seven young healthy males. Stepwise inspiration and expiration both resulted in an increase in heart rate followed by a rapid decrease in heart rate. The fastest heart rate was reached in 1.6 +/- 0.5 s and in 3.......6 +/- 1.4 s in response to inspiration and expiration, respectively (P less than 0.01). The slowest heart rate was reached in 4.8 +/- 1.0 s and in 7.6 +/- 1.9 s in response to inspiration and expiration, respectively (P less than 0.01). Following this biphasic change the heart rate returned to a steady...... level. The difference between the fastest and the slowest heart rates was significantly larger in response to inspiration (21.7 +/- 7.3 beats per minute) than in response to expiration (12.0 +/- 7.3 beats per minute; P less than 0.01). Periodic changes in lung volume were performed with frequencies from...

  1. Mesenchymal stem cells improve mouse non-heart-beating liver graft survival by inhibiting Kupffer cell apoptosis via TLR4-ERK1/2-Fas/FasL-caspase3 pathway regulation

    Directory of Open Access Journals (Sweden)

    Yang Tian

    2016-10-01

    Full Text Available Abstract Background Liver transplantation is the optimal treatment option for end-stage liver disease, but organ shortages dramatically restrict its application. Donation after cardiac death (DCD is an alternative approach that may expand the donor pool, but it faces challenges such as graft dysfunction, early graft loss, and cholangiopathy. Moreover, DCD liver grafts are no longer eligible for transplantation after their warm ischaemic time exceeds 30 min. Mesenchymal stem cells (MSCs have been proposed as a promising therapy for treatment of certain liver diseases, but the role of MSCs in DCD liver graft function remains elusive. Methods In this study, we established an arterialized mouse non-heart-beating (NHB liver transplantation model, and compared survival rates, cytokine and chemokine expression, histology, and the results of in vitro co-culture experiments in animals with or without MSC infusion. Results MSCs markedly ameliorated NHB liver graft injury and improved survival post-transplantation. Additionally, MSCs suppressed Kupffer cell apoptosis, Th1/Th17 immune responses, chemokine expression, and inflammatory cell infiltration. In vitro, PGE2 secreted by MSCs inhibited Kupffer cell apoptosis via TLR4-ERK1/2-caspase3 pathway regulation. Conclusion Our study uncovers a protective role for MSCs and elucidates the underlying immunomodulatory mechanism in an NHB liver transplantation model. Our results suggest that MSCs are uniquely positioned for use in future clinical studies owing to their ability to protect DCD liver grafts, particularly in patients for whom DCD organs are not an option according to current criteria.

  2. A quantitative high resolution voxel-wise assessment of myocardial blood flow from contrast-enhanced first-pass magnetic resonance perfusion imaging: microsphere validation in a magnetic resonance compatible free beating explanted pig heart model.

    Science.gov (United States)

    Schuster, Andreas; Sinclair, Matthew; Zarinabad, Niloufar; Ishida, Masaki; van den Wijngaard, Jeroen P H M; Paul, Matthias; van Horssen, Pepijn; Hussain, Shazia T; Perera, Divaka; Schaeffter, Tobias; Spaan, Jos A E; Siebes, Maria; Nagel, Eike; Chiribiri, Amedeo

    2015-10-01

    To assess the feasibility of high-resolution quantitative cardiovascular magnetic resonance (CMR) voxel-wise perfusion imaging using clinical 1.5 and 3 T sequences and to validate it using fluorescently labelled microspheres in combination with a state of the art imaging cryomicrotome in a novel, isolated blood-perfused MR-compatible free beating pig heart model without respiratory motion. MR perfusion imaging was performed in pig hearts at 1.5 (n = 4) and 3 T (n = 4). Images were acquired at physiological flow ('rest'), reduced flow ('ischaemia'), and during adenosine-induced hyperaemia ('stress') in control and coronary occlusion conditions. Fluorescently labelled microspheres and known coronary myocardial blood flow represented the reference standards for quantitative perfusion validation. For the comparison with microspheres, the LV was divided into 48 segments based on a subdivision of the 16 AHA segments into subendocardial, midmyocardial, and subepicardial subsegments. Perfusion quantification of the time-signal intensity curves was performed using a Fermi function deconvolution. High-resolution quantitative voxel-wise perfusion assessment was able to distinguish between occluded and remote myocardium (P < 0.001) and between rest, ischaemia, and stress perfusion conditions at 1.5 T (P < 0.001) and at 3 T (P < 0.001). CMR-MBF estimates correlated well with the microspheres at the AHA segmental level at 1.5 T (r = 0.94, P < 0.001) and at 3 T (r = 0.96, P < 0.001) and at the subendocardial, midmyocardial, and subepicardial level at 1.5 T (r = 0.93, r = 0.9, r = 0.88, P < 0.001, respectively) and at 3 T (r = 0.91, r = 0.95, r = 0.84, P < 0.001, respectively). CMR-derived voxel-wise quantitative blood flow assessment is feasible and very accurate compared with microspheres. This technique is suitable for both clinically used field strengths and may provide the tools to assess extent and severity of myocardial ischaemia. Published on behalf of the European Society

  3. Ultrasensitive cardiac troponin I antibody based nanohybrid sensor for rapid detection of human heart attack.

    Science.gov (United States)

    Bhatnagar, Deepika; Kaur, Inderpreet; Kumar, Ashok

    2017-02-01

    An ultrasensitive cardiac troponin I antibody conjugated with graphene quantum dots (GQD) and polyamidoamine (PAMAM) nanohybrid modified gold electrode based sensor was developed for the rapid detection of heart attack (myocardial infarction) in human. Screen printed gold (Au) electrode was decorated with 4-aminothiophenol for amine functionalization of the Au surface. These amino groups were further coupled with carboxyl functionalities of GQD with EDC-NHS reaction. In order to enhance the sensitivity of the sensor, PAMAM dendrimer was successively embedded on GQD through carbodiimide coupling to provide ultra-high surface area for antibody immobilization. The activated cardiac troponin I (cTnI) monoclonal antibody was immobilized on PAMAM to form nanoprobe for sensing specific heart attack marker cTnI. Various concentrations of cardiac marker, cTnI were electrochemically measured using cyclic voltammetry (CV) and differential pulse voltammetry (DPV) in human blood serum. The modifications on sensor surface were characterized by FTIR and AFM techniques. The sensor is highly specific to cTnI and showed negligible response to non-specific antigens. The sensitivity of the sensor was 109.23μAcm(-2)μg(-1) and lower limit of detection of cTnI was found 20fgmL(-1). Copyright © 2016 Elsevier B.V. All rights reserved.

  4. An efficient method for ectopic beats cancellation based on radial basis function.

    Science.gov (United States)

    Mateo, Jorge; Torres, Ana; Rieta, José J

    2011-01-01

    The analysis of the surface Electrocardiogram (ECG) is the most extended noninvasive technique in cardiological diagnosis. In order to properly use the ECG, we need to cancel out ectopic beats. These beats may occur in both normal subjects and patients with heart disease, and their presence represents an important source of error which must be handled before any other analysis. This paper presents a method for electrocardiogram ectopic beat cancellation based on Radial Basis Function Neural Network (RBFNN). A train-able neural network ensemble approach to develop customized electrocardiogram beat classifier in an effort to further improve the performance of ECG processing and to offer individualized health care is presented. Six types of beats including: Normal Beats (NB); Premature Ventricular Contractions (PVC); Left Bundle Branch Blocks (LBBB); Right Bundle Branch Blocks (RBBB); Paced Beats (PB) and Ectopic Beats (EB) are obtained from the MIT-BIH arrhythmia database. Four morphological features are extracted from each beat after the preprocessing of the selected records. Average Results for the RBFNN based method provided an ectopic beat reduction (EBR) of (mean ± std) EBR = 7, 23 ± 2.18 in contrast to traditional compared methods that, for the best case, yielded EBR = 4.05 ± 2.13. The results prove that RBFNN based methods are able to obtain a very accurate reduction of ectopic beats together with low distortion of the QRST complex.

  5. The effect of low-dose β-blocker on heart rate and heart rate variability in health subjects wth a resting heart rate of less than 65 beats per minute: Effect on the quality of prospective electrocardiography-gated coronary CT angiography

    Energy Technology Data Exchange (ETDEWEB)

    Park, Chul Hwan; Kim, Tae Hoon [Dept. of Radiology and Research Institute of Radiological Science, Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul (Korea, Republic of); Lee, Sang Min [Dept. of Radiology and Research Institute of Radiology, Asan Medical Center, University of Ulsan College of Medicine, Seoul (Korea, Republic of); Hong, Yoo Jin [Dept. of Radiology and Research Institute of Radiological Science, Severance Hospital, Yonsei University College of Medicine, Seoul (Korea, Republic of)

    2015-02-15

    We assessed the effect of a low-dose β-blocker on heart rate (HR), HR variability (HRV) and image quality of prospective electrocardiography-gated coronary CT angiography (CCTA) in healthy subjects with low HR. CCTA was performed with a 64-slice CT in 75 subjects with a HR of less than 65 beats per minute (bpm). Subjects were divided into 2 groups: Group 1 (G1), 35 with a low dose β-blocker; and Group 2 (G2), 40 without pre-medication. The image quality (IQ) of the CCTA was assessed on a 4-point grading scale (1, poor; 4, excellent). Initial HR (bpm) was not different between the 2 groups. HR during CCTA was lower in G1 than G2 (50.3 ± 5.6 vs. 53.3 ± 4.8, p = 0.016). HRV was not different between the 2 groups. Per-segment analysis showed better IQ at the mid-segment of the right coronary artery (3.0 ± 0.9 vs. 2.5 ± 1.1, p = 0.039) and the first diagonal branch (3.4 ± 0.6 vs. 3.1 ± 0.7, p = 0.024), in the G1 than the G2 group, respectively. The IQ was negatively correlated with HR, but no correlation was found between HRV and IQ. The IQs in the per-vessel analysis were not different between the 2 groups. Low-dose β-blocker reduced HR and improved the IQ of CCTA in a few segments, even at a HR of less than 65 bpm. However the effect was limited.

  6. A computer-based matrix for rapid calculation of pulmonary hemodynamic parameters in congenital heart disease

    Directory of Open Access Journals (Sweden)

    Lopes Antonio

    2009-01-01

    Full Text Available Background : In patients with congenital heart disease undergoing cardiac catheterization for hemodynamic purposes, parameter estimation by the indirect Fick method using a single predicted value of oxygen consumption has been a matter of criticism. Objective : We developed a computer-based routine for rapid estimation of replicate hemodynamic parameters using multiple predicted values of oxygen consumption. Materials and Methods : Using Microsoft ® Excel facilities, we constructed a matrix containing 5 models (equations for prediction of oxygen consumption, and all additional formulas needed to obtain replicate estimates of hemodynamic parameters. Results : By entering data from 65 patients with ventricular septal defects, aged 1 month to 8 years, it was possible to obtain multiple predictions for oxygen consumption, with clear between-age groups ( P < .001 and between-methods ( P < .001 differences. Using these predictions in the individual patient, it was possible to obtain the upper and lower limits of a likely range for any given parameter, which made estimation more realistic. Conclusion : The organized matrix allows for rapid obtainment of replicate parameter estimates, without error due to exhaustive calculations.

  7. A computer-based matrix for rapid calculation of pulmonary hemodynamic parameters in congenital heart disease.

    Science.gov (United States)

    Lopes, Antonio Augusto; Dos Anjos Miranda, Rogério; Gonçalves, Rilvani Cavalcante; Thomaz, Ana Maria

    2009-07-01

    In patients with congenital heart disease undergoing cardiac catheterization for hemodynamic purposes, parameter estimation by the indirect Fick method using a single predicted value of oxygen consumption has been a matter of criticism. We developed a computer-based routine for rapid estimation of replicate hemodynamic parameters using multiple predicted values of oxygen consumption. Using Microsoft® Excel facilities, we constructed a matrix containing 5 models (equations) for prediction of oxygen consumption, and all additional formulas needed to obtain replicate estimates of hemodynamic parameters. By entering data from 65 patients with ventricular septal defects, aged 1 month to 8 years, it was possible to obtain multiple predictions for oxygen consumption, with clear between-age groups (P <.001) and between-methods (P <.001) differences. Using these predictions in the individual patient, it was possible to obtain the upper and lower limits of a likely range for any given parameter, which made estimation more realistic. The organized matrix allows for rapid obtainment of replicate parameter estimates, without error due to exhaustive calculations.

  8. Patient-specific ECG beat classification technique.

    Science.gov (United States)

    Das, Manab K; Ari, Samit

    2014-09-01

    Electrocardiogram (ECG) beat classification plays an important role in the timely diagnosis of the critical heart condition. An automated diagnostic system is proposed to classify five types of ECG classes, namely normal (N), ventricular ectopic beat (V), supra ventricular ectopic beat (S), fusion (F) and unknown (Q) as recommended by the Association for the Advancement of Medical Instrumentation (AAMI). The proposed method integrates the Stockwell transform (ST), a bacteria foraging optimisation (BFO) algorithm and a least mean square (LMS)-based multiclass support vector machine (SVM) classifier. The ST is utilised to extract the important morphological features which are concatenated with four timing features. The resultant combined feature vector is optimised by removing the redundant and irrelevant features using the BFO algorithm. The optimised feature vector is applied to the LMS-based multiclass SVM classifier for automated diagnosis. In the proposed technique, the LMS algorithm is used to modify the Lagrange multiplier, which in turn modifies the weight vector to minimise the classification error. The updated weights are used during the testing phase to classify ECG beats. The classification performances are evaluated using the MIT-BIH arrhythmia database. Average accuracy and sensitivity performances of the proposed system for V detection are 98.6% and 91.7%, respectively, and for S detections, 98.2% and 74.7%, respectively over the entire database. To generalise the capability, the classification performance is also evaluated using the St. Petersburg Institute of Cardiological Technics (INCART) database. The proposed technique performs better than other reported heartbeat techniques, with results suggesting better generalisation capability.

  9. Heart beats from the dark side

    Science.gov (United States)

    Chang, Jin

    2018-01-01

    The Dark Matter Particle Explorer (DAMPE) satellite is currently in orbit measuring cosmic rays to research their origin and propagation and also to find possible hidden signatures of dark matter, emphasizes Principal Investigator Jin Chang.

  10. Measuring Cosmic Distances with Stellar Heart Beats

    Science.gov (United States)

    2004-10-01

    VLTI Watches the Changing Size of Bright Southern Cepheids Summary Taking advantage of the very high spatial resolution provided by the Very Large Telescope Interferometer, a team of French and Swiss astronomers [1] has measured directly the change in angular diameter of four southern Cepheid variable stars over their pulsation cycle. When combined with spectroscopic radial velocity measurements, this allowed the astronomers to measure very accurately the distances of these stars in a quasi-geometrical way, and to calibrate the zero-point of the Cepheid Period-Luminosity empirical law. These observations constitute a fundamental step towards an independent verification of the extragalactic distance scale by interferometry. PR Photo 30a/04: Observation Techniques of the Baade-Wesselink Method. PR Photo 30b/04: Paranal Platform and VLTI Baselines Used. PR Photo 30c/04: Pulsation of the Cepheid Variable L Car. (VINCI/VLTI) PR Photo 30d/04: Period-Luminosity relation for Cepheids. (VINCI/VLTI) Cepheids and the cosmic distance ladder It is very difficult to measure the distance to an astronomical object. In fact, this is one of the greatest challenges facing astronomers. There is indeed no accurate, direct way to determine the distance to galaxies beyond the Milky Way: astronomers first determine the distance to nearby stars in our galaxy as accurately as possible and then use a series of other techniques that reach progressively further into space to estimate distances to more distant systems. This process is often referred as the "cosmic distance ladder". Over the years, a number of different distance estimators have been found. One of these is a particular class of stars known as Cepheid variables. They are used as one of the first "steps" on this cosmic distance ladder. Cepheids are rare and very luminous stars whose luminosity varies in a very regular way. They are named after the star Delta Cephei in the constellation of Cepheus, the first known variable star of this particular type and bright enough to be easily seen with the unaided eye. In 1912, American astronomer Henrietta Leavitt observed 20 variable stars of the Cepheid-type in the Small Magellanic Cloud (SMC), one of the closest galaxies to the Milky Way. For all purposes, these stars are all at the same distance (the size of the SMC is negligible compared to its much larger distance from us). Apparently brighter stars in this group are thus also intrinsically brighter (more luminous). Henrietta Leavitt discovered a basic relation between the intrinsic brightness and the pulsation period of Cepheid variable stars in the SMC and showed that intrinsically brighter Cepheids have longer periods. This relation is now known as the "Period-Luminosity relation" and is an important way to derive the distance to stars of this type. By measuring the period of a Cepheid star, its intrinsic brightness can be deduced and from the observed apparent brightness, the distance may then be calculated. In this way, Cepheid stars are used by astronomers as one of the "standard candles" in the Universe. They act either as distance indicators themselves or are used to calibrate other distance indicators. The Cepheid stars have taken on an even more important role since the Hubble Space Telescope Key Project on the extragalactic distance scale relies completely on them for the calibration of distance indicators to reach cosmologically large distances. In other words, if the calibration of the Cepheid Period-Luminosity relation were wrong, the entire extragalactic distance scale and with it, the rate of cosmic expansion and the related acceleration, as well as the estimated age of the Universe, would also be off. A main problem is thus to calibrate as accurately as possible the Period-Luminosity relation for nearby Cepheids. This requires measuring their distances with the utmost precision, a truly daunting task. And this is where interferometry now enters the picture. The Baade-Wesselink method ESO PR Photo 30a/04 ESO PR Photo 30a/04 Title [Preview - JPEG: 400 x 345 pix - 104k] [Normal - JPEG: 800 x 690 pix - 229k] Caption of ESO PR Photo 30a/04: The two observation techniques used for the interferometric version of the Baade-Wesselink method are high-resolution spectroscopy (left) and interferometry (right). The former provides the radial velocity curve over the pulsation cycle of the star. When integrated, this in turn provides the linear radius variation of the star (in metres). The interferometric observations document variation of the star's angular radius. The ratio of these two quantities gives the distance of the Cepheid. Independent determinations of the distance of variable stars make use of the so-called Baade-Wesselink method, named after astronomers Walter Baade (1893 - 1960) and Adriaan Wesselink (1909 - 1995). With this classical method, the variation of the angular diameter of a Cepheid variable star is inferred from the measured changes in brightness (by means of model atmosphere calculations) as it pulsates. Spectroscopy is then used to measure the corresponding radial velocity variations, hence providing the linear distance over which the star's outer layers have moved. By dividing the angular and linear measures, the distance to the star is obtained. This sounds straightforward. However, it would obviously be much better to measure the variation of the radius directly and not to rely on model atmosphere calculations. But here the main problem is that, despite their apparent brightness, all Cepheids are situated at large distances. Indeed, the closest Cepheid star (excluding the peculiar star Polaris), Delta Cephei, is more than 800 light-years away. Even the largest Cepheids in the sky subtend an angle of only 0.003 arcsec. To observe this is similar to view a two-storey house on the Moon. And what astronomers want to do is to measure the change of the stars' sizes, amounting to only a fraction of this! Such an observing feat is only possible with long-baseline interferometry. Also on this front, the VLT Interferometer is now opening a new field of observational astrophysics. Three VLTI baselines ESO PR Photo 30b/04 ESO PR Photo 30b/04 Title [Preview - JPEG: 400 x 345 pix - 112k] [Normal - JPEG: 800 x 690 pix - 276k] Caption: ESO PR Photo 30b/04 is a view of the Paranal platform with the three baselines used for the VLTI observations of Cepheids (in red). ESO PR Photo 30c/04 ESO PR Photo 30c/04 Title [Preview - JPEG: 400 x 367 pix - 88k] [Normal - JPEG: 800 x 734 pix - 180k] Caption: ESO PR Photo 30c/04 shows the VINCI observations of the pulsation of the Cepheid variable L Car (P = 35.5 days, red dots) and the adjusted radius curve (green line), as deduced from the integration of the radial velocity measured on this star over its pulsation period. Some time ago, an undaunted team of French and Swiss astronomers [1] started a major research programme aimed at measuring the distance to several Cepheids by means of the above outlined Baade-Wesselink interferometric method. For these observations they combined sets of two beams - one set from the two VLTI Test Siderostats with 0.35m aperture and the other set from two Unit Telescopes (Antu and Melipal; 8.2m mirrors) - with the VINCI (VLT Interferometer Commissioning Instrument) facility. Three VLTI baselines were used for this programme with, respectively, 66, 140 and 102.5m ground length. ESO PR Photo 30b/04 shows the respective positions on the VLTI platform. The observations were made in the near-infrared K-band. A total of 69 individual angular diameter measurements were obtained with the VLTI, over more than 100 hours of total telescope time, distributed over 68 nights; the largest angular diameter measured was 0.0032 arcsec (L Car at maximum). Seven Cepheids observable from Paranal Observatory were selected for this programme: X and W Sagittarii, Eta Aquilae, Beta Doradus, Zeta Gemini, Y Ophiocus and L Carinae. Their periods range from 7 to 35.5 days, a fairly wide interval and an important advantage to properly calibrate the Period-Luminosity relation. The distances to four of the stars (Eta Aql, W Sgr, Beta Dor and L Car) were derived using the interferometric Baade-Wesselink method, as their pulsation is detected by the VLTI. ESO PR Photo 30c/04 shows the angular diameter measurements and the fitted radius curve of L Car (P = 35.5 days); this measures its distance with a relative precision better than 5%. For the remaining three objects of the sample (X Sgr, Zeta Gem and Y Oph), a hybrid method was applied to derive their distances, based on their average angular diameter and pre-existing estimations of their linear diameters. The new calibration ESO PR Photo 30d/04 ESO PR Photo 30d/04 Title [Preview - JPEG: 400 x 365 pix - 80k] [Normal - JPEG: 800 x 730 pix - 168k] Caption: ESO PR Photo 30d/04 represents the Period-Luminosity relation in the V band, as deduced from the interferometric observations of Cepheids and the HST parallax measurement of Delta Cep. The green line is the fitted P-L relation, assuming the slope from previous authors (Gieren et al.; 1998, ApJ, 496, 17). The agreement between the model and the measurements is excellent, in particular for the high-precision measurements of Delta Cep and L Car. Combining the distances measured by this programme with the apparent magnitudes of the stars, the astronomers determined the absolute magnitude (intrinsic brightness) of these stars and arrived at a very precise calibration of the zero-point of the Period-Luminosity relation (assuming the slope from previous work). It turned out that this new and independently derived value of the zero-point is exactly the same as the one obtained during previous work based on a large number of relatively low-precision Cepheid distance measurements by the ESA Hipparcos astrometric satellite. The agreement between these two independent, geometrical calibrations is remarkable and greatly increases the confidence in the cosmic distance scale now in use. Prospects with AMBER With 1.8m Auxiliary Telescopes soon to be ready on the VLTI platform, the astronomers will be able to observe many more Cepheids with a precision at least as good as the present high-precision VINCI observations of L Car. In addition, the future AMBER instrument will extend the VLTI capabilities toward shorter wavelengths (J and H bands), providing even higher spatial resolution than what is now possible with VINCI (K band). The combined effect of these two improvements will be to extend significantly the accessible sample of Cepheids. It is expected that the distances to more than 30 Cepheids will then be measurable with a precision better than 5%. This will provide a high precision calibration of both the reference point (down to ±0.01 mag) and the slope of the Galactic Cepheid Period-Luminosity. More information The information contained in this press release is based on a series of three research articles which are being published by the European research journal "Astronomy & Astrophysics" by P. Kervella and collaborators (Paper I : 2004, A&A, 416, 941, Paper II : 2004, A&A, 423, 327 and Paper III : in press). The present press release is published exactly three years after the first observations with two 8.2-m VLT Unit Telescopes and the VLTI with VINCI were achieved, cf. ESO PR 23/01. Note [1]: The team consists of Pierre Kervella and Vincent Coudé du Foresto at the Paris Observatory in France, David Bersier of the Space Telescope Science Institute (USA), Nicolas Nardetto and Denis Mourard (Observatoire de la Côte d'Azur, France), and Pascal Fouqué (Observatoire Midi-Pyré né es, France).

  11. Xenoreactive natural antibodies and induced antibodies--their effects of beating cardiomyocytes as a model of a xenograft.

    Science.gov (United States)

    Müller-Werdan, U; Koidl, B; Autenrieth, A; Klein, D; Werdan, K; Hammer, C

    1996-01-01

    Xenotransplantation has been complicated by hyperacute rejection reactions, which are supposedly triggered by preformed natural antibodies (PNAb) of the recipient organism, whereas the role of antibodies specifically induced by previous antigen contact (IAb) is less clear. Primary cultures of spontaneously beating neonatal rat cardiomyocytes were used as a model of the heart to elaborate the effects of both PNAb and IAb from xenogeneic species and to investigate into their mechanisms of action. An experimental setup allowing for rapid medium exchange under continuous observation was employed. Sera containing PNAb reproducibly bring about a stereotype pattern of altered contractility including an initial increase in beating frequency followed by a temporary cessation of beating within the first minutes after administration. After recovery of spontaneous contractions, the cells within the monolayer exhibited a dissociation of the synchronicity of the beating persisting for several hours. The temporary pause in beating was prevented by a very high extracellular calcium concentration, but not by extracellular electrical stimulation sufficient to trigger contractions in control cells. Electrophysiological measurements carried out in adult ventricular guinea pig heart muscle cells under the same experimental conditions revealed an increase of the excitation threshold of the cells after application of sera containing PNAb due to an enhanced input resistance. These results indicate that the effect of PNAb is the consequence rather of a generally reduced excitability of the cell than of the inhibition of a singular ionic conductance. After specific absorption of PNAb directed against rat antigens beating of neonatal rate cardiomyocytes ensued without interruption. Sera specimens devoid of complement produced similar effects on contractility, although the duration of the standstill period was significantly shorter. The increase in input resistance visualized in guinea pig

  12. Effect of slow versus rapid rewarming on jugular bulb oxygen saturation in adult patients undergoing open heart surgery

    Directory of Open Access Journals (Sweden)

    Mohmaed Shaaban Ali

    2014-01-01

    Full Text Available Background: A debate has appeared in the recent literature about the optimum rewarming strategy (slow vs. rapid for the best brain function. This study was designed to compare the effect of slow versus rapid rewarming on jugular bulb oxygen saturation (SjO 2 in adult patients undergoing open heart surgery. Materials and Methods: A total of 80 patients undergoing valve and adult congenital heart surgery were randomly allocated equally to rapid rewarming group 0.5 (0.136°C/min and slow rewarming group 0.219 (0.055°C/min in jugular bulb sampling was taken before, during and after surgery. Surgery was done at cardiopulmonary bypass (CPB temperature of 28-30°C and rewarming was performed at the end of the surgical procedure. Results: CPB time, rewarming period were significantly longer in the slow rewarming group. Significant difference was observed in the number of the desaturated patients (SjO 2 ≤ 50% between the two groups; 14 (35% in rapid rewarming versus 6 (15% in the slow rewarming group; P = 0.035 by Fisher′s exact test. Conclusions: Slow rewarming could reduce the incidence of SjO 2 desaturation during rewarming in adult patients undergoing open heart surgery.

  13. Use of beat-to-beat cardiovascular variability data to determine the validity of sham therapy as the placebo control in osteopathic manipulative medicine research.

    Science.gov (United States)

    Henley, Charles E; Wilson, Thad E

    2014-11-01

    Osteopathic manipulative medicine researchers often use sham therapy as the placebo control during clinical trials. Optimally, the sham therapy should be a hands-on procedure that is perceptually indistinguishable from osteopathic manipulative treatment, does not create an effect on its own, and is not a treatment intervention. However, the sham therapy itself may often influence the outcome. The use of cardiovascular variability (eg, beat-to-beat heart rate variability) as a surrogate for the autonomic nervous system is one objective method by which to identify such an effect. By monitoring cardiovascular variability, investigators can assess autonomic nervous system activity as a response to the sham therapy and quickly determine whether or not the selected sham therapy is a true placebo control. The authors provide evidence for assessment of beat-to-beat heart rate variability as one method for assuring objectivity of sham therapy as a placebo control in osteopathic manipulative medicine research. © 2014 The American Osteopathic Association.

  14. An algorithm for the beat-to-beat assessment of cardiac mechanics during sleep on Earth and in microgravity from the seismocardiogram.

    Science.gov (United States)

    Di Rienzo, Marco; Vaini, Emanuele; Lombardi, Prospero

    2017-11-15

    Seismocardiogram, SCG, is the measure of precordial vibrations produced by the beating heart, from which cardiac mechanics may be explored on a beat-to-beat basis. We recently collected a large amount of SCG data (>69 recording hours) from an astronaut to investigate cardiac mechanics during sleep aboard the International Space Station and on Earth. SCG sleep recordings are characterized by a prolonged duration and wide heart rate swings, thus a specific algorithm was developed for their analysis. In this article we describe the new algorithm and its performance. The algorithm is composed of three parts: 1) artifacts removal, 2) identification in each SCG waveform of four fiducial points associated with the opening and closure of the aortic and mitral valves, 3) beat-to-beat computation of indexes of cardiac mechanics from the SCG fiducial points. The algorithm was tested on two sleep recordings and yielded the identification of the fiducial points in more than 36,000 beats with a precision, quantified by the Positive Predictive Value, ≥99.2%. These positive findings provide the first evidence that cardiac mechanics may be explored by the automatic analysis of SCG long-lasting recordings, taken out of the laboratory setting, and in presence of significant heart rate modulations.

  15. Improving assessment of congenital heart disease through rapid patient specific modeling.

    Science.gov (United States)

    Gilbert, Kathleen; Farrar, Genevieve; Cowan, Brett; Suinesiaputra, Avan; Occleshaw, Christopher; Pontre, Beau; Perry, James; Hegde, Sanjeet; Omens, Jeffrey; McCulloch, Andrew; Young, Alistair

    2016-08-01

    Congenital heart disease is the most common birth defect, with an incidence of 75 in every 1000 births. As a result of improved interventions, 90% of people with congenital heart disease now survive to adulthood. They must undergo regular imaging to assess their biventricular (left and right ventricular) function. Analysis of the images is problematic due to the large variety of shapes and complex geometry. In this paper we extend a biventricular modeling method to improve the analysis of MR images from congenital heart disease patients. We used a subdivision surface method to create three customizable exemplars, representing common manifestations of anatomy, and incorporated these as priors into an interactive biventricular customization procedure. The CHD-specific priors were tested on 60 cases representing a variety of congenital heart diseases for which the gold standard manual contours were available. The introduction of multiple priors showed a significant decrease in analysis time while maintaining good correlation between the two methods (R2 >.82).

  16. Automatic Arrhythmia Beat Detection: Algorithm, System, and Implementation

    Directory of Open Access Journals (Sweden)

    Wisnu Jatmiko

    2016-08-01

    Full Text Available Cardiac disease is one of the major causes of death in the world. Early diagnose of the symptoms depends on abnormality on heart beat pattern, known as Arrhythmia. A novel fuzzy neuro generalized learning vector quantization for automatic Arrhythmia heart beat classification is proposed. The algorithm is an extension from theGLVQ algorithm that employs a fuzzy logic concept as the discriminant function in order to develop a robust algorithmand improve the classification performance. The algorithm is testedagainst MIT-BIH arrhythmia database to measure theperformance. Based on the experiment result, FN-GLVQ is able to increase the accuracy of GLVQ by a soft margin. As we intend to build a device with automated Arrhythmia detection,FN-GLVQ is then implemented into Field Gate Programmable Array to prototype the system into a real device.

  17. To Beat or Not to Beat: Beat Gestures in Direction Giving

    NARCIS (Netherlands)

    Theune, Mariet; Brandhorst, Chris J.; Kopp, S.; Wachsmuth, I.

    2010-01-01

    Research on gesture generation for embodied conversational agents (ECA’s) mostly focuses on gesture types such as pointing and iconic gestures, while ignoring another gesture type frequently used by human speakers: beat gestures. Analysis of a corpus of route descriptions showed that although

  18. Rapid Heartbeat, But Dry Palms: Reactions of Heart Rate and Skin Conductance Levels to Social Rejection

    Directory of Open Access Journals (Sweden)

    Benjamin eIffland

    2014-08-01

    Full Text Available Background: Social rejection elicits negative mood, emotional distress and neural activity in networks that are associated with physical pain. However, studies assessing physiological reactions to social rejection are rare and results of these studies were found to be ambiguous. Therefore, the present study aimed to examine and specify physiological effects of social rejection.Methods: Participants (N = 50 were assigned to either a social exclusion or inclusion condition of a virtual ball-tossing game (Cyberball. Immediate and delayed physiological (skin conductance level and heart rate reactions were recorded. In addition, subjects reported levels of affect, emotional states and fundamental needs.Results: Subjects who were socially rejected showed increased heart rates. However, social rejection had no effect on subjects’ skin conductance levels. Both conditions showed heightened arousal on this measurement. Furthermore, psychological consequences of social rejection indicated the validity of the paradigm.Conclusions: Our results reveal that social rejection evokes an immediate physiological reaction. Accelerated heart rates indicate that behavior activation rather than inhibition is associated with socially threatening events. In addition, results revealed gender-specific response patterns suggesting that sample characteristics such as differences in gender may account for ambiguous findings of physiological reactions to social rejection.

  19. Rapid heartbeat, but dry palms: reactions of heart rate and skin conductance levels to social rejection.

    Science.gov (United States)

    Iffland, Benjamin; Sansen, Lisa M; Catani, Claudia; Neuner, Frank

    2014-01-01

    Social rejection elicits negative mood, emotional distress, and neural activity in networks that are associated with physical pain. However, studies assessing physiological reactions to social rejection are rare and results of these studies were found to be ambiguous. Therefore, the present study aimed to examine and specify physiological effects of social rejection. Participants (n = 50) were assigned to either a social exclusion or inclusion condition of a virtual ball-tossing game (Cyberball). Immediate and delayed physiological [skin conductance level (SCL) and heart rate] reactions were recorded. In addition, subjects reported levels of affect, emotional states, and fundamental needs. Subjects who were socially rejected showed increased heart rates. However, social rejection had no effect on subjects' SCLs. Both conditions showed heightened arousal on this measurement. Furthermore, psychological consequences of social rejection indicated the validity of the paradigm. Our results reveal that social rejection evokes an immediate physiological reaction. Accelerated heart rates indicate that behavior activation rather than inhibition is associated with socially threatening events. In addition, results revealed gender-specific response patterns suggesting that sample characteristics such as differences in gender may account for ambiguous findings of physiological reactions to social rejection.

  20. Using optical coherence tomography to rapidly phenotype and quantify congenital heart defects associated with prenatal alcohol exposure.

    Science.gov (United States)

    Karunamuni, Ganga; Gu, Shi; Doughman, Yong Qiu; Noonan, Amanda I; Rollins, Andrew M; Jenkins, Michael W; Watanabe, Michiko

    2015-04-01

    The most commonly used method to analyze congenital heart defects involves serial sectioning and histology. However, this is often a time-consuming process where the quantification of cardiac defects can be difficult due to problems with accurate section registration. Here we demonstrate the advantages of using optical coherence tomography, a comparatively new and rising technology, to phenotype avian embryo hearts in a model of fetal alcohol syndrome where a binge-like quantity of alcohol/ethanol was introduced at gastrulation. The rapid, consistent imaging protocols allowed for the immediate identification of cardiac anomalies, including ventricular septal defects and misaligned/missing vessels. Interventricular septum thicknesses and vessel diameters for three of the five outflow arteries were also significantly reduced. Outflow and atrioventricular valves were segmented using image processing software and had significantly reduced volumes compared to controls. This is the first study to our knowledge that has 3D reconstructed the late-stage cardiac valves in precise detail to examine their morphology and dimensions. We believe, therefore, that optical coherence tomography, with its ability to rapidly image and quantify tiny embryonic structures in high resolution, will serve as an excellent and cost-effective preliminary screening tool for developmental biologists working with a variety of experimental/disease models. © 2014 Wiley Periodicals, Inc.

  1. The angiotensin type 1 receptor activates extracellular signal-regulated kinases 1 and 2 by G protein-dependent and -independent pathways in cardiac myocytes and langendorff-perfused hearts

    DEFF Research Database (Denmark)

    Aplin, Mark; Christensen, Gitte Lund; Schneider, Mikael

    2007-01-01

    II) analogue in native preparations of cardiac myocytes and beating hearts. We found that [SII] AngII does not activate G(q)-coupling, yet stimulates the beta-arrestin2-dependent ERK1/2. The G(q)-activated pool of ERK1/2 rapidly translocates to the nucleus, while the beta-arrestin2-scaffolded pool remains...

  2. Beat-to-beat variability of cardiac action potential duration: underlying mechanism and clinical implications.

    Science.gov (United States)

    Nánási, Péter P; Magyar, János; Varró, András; Ördög, Balázs

    2017-10-01

    Beat-to-beat variability of cardiac action potential duration (short-term variability, SV) is a common feature of various cardiac preparations, including the human heart. Although it is believed to be one of the best arrhythmia predictors, the underlying mechanisms are not fully understood at present. The magnitude of SV is basically determined by the intensity of cell-to-cell coupling in multicellular preparations and by the duration of the action potential (APD). To compensate for the APD-dependent nature of SV, the concept of relative SV (RSV) has been introduced by normalizing the changes of SV to the concomitant changes in APD. RSV is reduced by I Ca , I Kr , and I Ks while increased by I Na , suggesting that ion currents involved in the negative feedback regulation of APD tend to keep RSV at a low level. RSV is also influenced by intracellular calcium concentration and tissue redox potential. The clinical implications of APD variability is discussed in detail.

  3. Reduced intrinsic heart rate is associated with reduced arrhythmic susceptibility in guinea-pig heart.

    Science.gov (United States)

    Osadchii, Oleg E

    2014-12-01

    In the clinical setting, patients with slower resting heart rate are less prone to cardiovascular death compared with those with elevated heart rate. However, electrophysiological adaptations associated with reduced cardiac rhythm have not been thoroughly explored. In this study, relationships between intrinsic heart rate and arrhythmic susceptibility were examined by assessments of action potential duration (APD) rate adaptation and inducibility of repolarization alternans in sinoatrial node (SAN)-driven and atrioventricular (AV)-blocked guinea-pig hearts perfused with Langendorff apparatus. Electrocardiograms, epicardial monophasic action potentials, and effective refractory periods (ERP) were assessed in normokalemic and hypokalemic conditions. Slower basal heart rate in AV-blocked hearts was associated with prolonged ventricular repolarization during spontaneous beating, and with attenuated APD shortening at increased cardiac activation rates during dynamic pacing, when compared with SAN-driven hearts. During hypokalemic perfusion, the inducibility of repolarization alternans and tachyarrhythmia by rapid pacing was found to be lower in AV-blocked hearts. This difference was ascribed to prolonged ERP in the setting of reduced basal heart rate, which prevented ventricular capture at critically short pacing intervals required to induce arrhythmia. Reduced basal heart rate is associated with electrophysiological changes that prevent electrical instability upon an abrupt cardiac acceleration.

  4. Ectopic beats in approximate entropy and sample entropy-based HRV assessment

    Science.gov (United States)

    Singh, Butta; Singh, Dilbag; Jaryal, A. K.; Deepak, K. K.

    2012-05-01

    Approximate entropy (ApEn) and sample entropy (SampEn) are the promising techniques for extracting complex characteristics of cardiovascular variability. Ectopic beats, originating from other than the normal site, are the artefacts contributing a serious limitation to heart rate variability (HRV) analysis. The approaches like deletion and interpolation are currently in use to eliminate the bias produced by ectopic beats. In this study, normal R-R interval time series of 10 healthy and 10 acute myocardial infarction (AMI) patients were analysed by inserting artificial ectopic beats. Then the effects of ectopic beats editing by deletion, degree-zero and degree-one interpolation on ApEn and SampEn have been assessed. Ectopic beats addition (even 2%) led to reduced complexity, resulting in decreased ApEn and SampEn of both healthy and AMI patient data. This reduction has been found to be dependent on level of ectopic beats. Editing of ectopic beats by interpolation degree-one method is found to be superior to other methods.

  5. The cerebellum's contribution to beat interval discrimination.

    Science.gov (United States)

    Paquette, S; Fujii, S; Li, H C; Schlaug, G

    2017-12-01

    From expert percussionists to individuals who cannot dance, there are widespread differences in people's abilities to perceive and synchronize with a musical beat. The aim of our study was to identify candidate brain regions that might be associated with these abilities. For this purpose, we used Voxel-Based-Morphometry to correlate inter-individual differences in performance on the Harvard Beat Assessment Tests (H-BAT) with local inter-individual variations in gray matter volumes across the entire brain space in 60 individuals. Analysis revealed significant co-variations between performances on two perceptual tasks of the Harvard Beat Assessment Tests associated with beat interval change discrimination (faster, slower) and gray matter volume variations in the cerebellum. Participant discrimination thresholds for the Beat Finding Interval Test (quarter note beat) were positively associated with gray matter volume variation in cerebellum lobule IX in the left hemisphere and crus I bilaterally. Discrimination thresholds for the Beat Interval Test (simple series of tones) revealed the tendency for a positive association with gray matter volume variations in crus I/II of the left cerebellum. Our results demonstrate the importance of the cerebellum in beat interval discrimination skills, as measured by two perceptual tasks of the Harvard Beat Assessment Tests. Current findings, in combination with evidence from patients with cerebellar degeneration and expert dancers, suggest that cerebellar gray matter and overall cerebellar integrity are important for temporal discrimination abilities. Copyright © 2017 Elsevier Inc. All rights reserved.

  6. The impact of binaural beats on creativity

    National Research Council Canada - National Science Library

    Reedijk, Susan A; Bolders, Anne; Hommel, Bernhard

    2013-01-01

    ... through stimulating neuronal phase locking. We aimed to investigate whether binaural beats affect creative performance at all, whether they affect divergent thinking, convergent thinking, or both, and...

  7. Auditory driving of the autonomic nervous system: Listening to theta-frequency binaural beats post-exercise increases parasympathetic activation and sympathetic withdrawal

    OpenAIRE

    Patrick eMcConnell; Patrick eMcConnell; Brett eFroeliger; Eric L. Garland; Jeffrey C. Ives; Gary A. Sforzo

    2014-01-01

    Binaural beats are an auditory illusion perceived when two or more pure tones of similar frequencies are presented dichotically through stereo headphones. Although this phenomenon is thought to facilitate state changes (e.g., relaxation), few empirical studies have reported on whether binaural beats produce changes in autonomic arousal. Therefore, the present study investigated the effects of binaural beating on autonomic dynamics (heart-rate variability (HRV)) during post-exercise relaxation...

  8. Auditory driving of the autonomic nervous system: Listening to theta-frequency binaural beats post-exercise increases parasympathetic activation and sympathetic withdrawal

    OpenAIRE

    McConnell, Patrick A.; Froeliger, Brett; Garland, Eric L.; Ives, Jeffrey C.; Sforzo, Gary A.

    2014-01-01

    Binaural beats are an auditory illusion perceived when two or more pure tones of similar frequencies are presented dichotically through stereo headphones. Although this phenomenon is thought to facilitate state changes (e.g., relaxation), few empirical studies have reported on whether binaural beats produce changes in autonomic arousal. Therefore, the present study investigated the effects of binaural beating on autonomic dynamics [heart rate variability (HRV)] during post-exercise relaxation...

  9. A heart that beats for 500 years: age-related changes in cardiac proteasome activity, oxidative protein damage and expression of heat shock proteins, inflammatory factors, and mitochondrial complexes in Arctica islandica, the longest-living noncolonial animal.

    Science.gov (United States)

    Sosnowska, Danuta; Richardson, Chris; Sonntag, William E; Csiszar, Anna; Ungvari, Zoltan; Ridgway, Iain

    2014-12-01

    Study of negligibly senescent animals may provide clues that lead to better understanding of the cardiac aging process. To elucidate mechanisms of successful cardiac aging, we investigated age-related changes in proteasome activity, oxidative protein damage and expression of heat shock proteins, inflammatory factors, and mitochondrial complexes in the heart of the ocean quahog Arctica islandica, the longest-lived noncolonial animal (maximum life span potential: 508 years). We found that in the heart of A. islandica the level of oxidatively damaged proteins did not change significantly up to 120 years of age. No significant aging-induced changes were observed in caspase-like and trypsin-like proteasome activity. Chymotrypsin-like proteasome activity showed a significant early-life decline, then it remained stable for up to 182 years. No significant relationship was observed between the extent of protein ubiquitination and age. In the heart of A. islandica, an early-life decline in expression of HSP90 and five mitochondrial electron transport chain complexes was observed. We found significant age-related increases in the expression of three cytokine-like mediators (interleukin-6, interleukin-1β, and tumor necrosis factor-α) in the heart of A. islandica. Collectively, in extremely long-lived molluscs, maintenance of protein homeostasis likely contributes to the preservation of cardiac function. Our data also support the concept that low-grade chronic inflammation in the cardiovascular system is a universal feature of the aging process, which is also manifest in invertebrates. © The Author 2013. Published by Oxford University Press on behalf of The Gerontological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  10. Detection and removal of ventricular ectopic beats in atrial fibrillation recordings via principal component analysis.

    Science.gov (United States)

    Martínez, Arturo; Alcaraz, Raúl; Rieta, José J

    2011-01-01

    Ectopic beats are early heart beats with remarkable large amplitude that provoke serious disturbances in the analysis of electrocardiograms (ECG). These beats are very common in atrial fibrillation (AF) and are the source of important residua when the QRST is intended to be removed. Given that QRST cancellation is a binding step in the appropriate analysis of atrial activity (AA) in AF, a method for ventricular ectopic beats cancellation is proposed as a previous step to the application of any QRST removal technique. First, the method discriminates between normal and ectopic beats with an accuracy higher than 99% through QRS morphological characterization. Next, the most similar ectopic beats to the one under cancellation are clustered and serve to get their eigenvector matrix by principal component analysis. Finally, the highest variance eigenvector is used as cancellation template. The reduction ectopic rate (RER) has been defined to evaluate the method's performance by using templates generated with 5, 10, 20, 40 or 80 ectopics. Optimal results were reached with the 5 most similar complexes, yielding a RER higher than 5.5. In addition, a decreasing RER trend was noticed as the number of considered ectopics for cancellation increased. As conclusion, given that ectopics presented a remarkable variability in their morphology, the proposed cancellation approach is a robust ectopic remover and can notably facilitate the later application of any QRST cancellation technique to extract the AA in the best conditions.

  11. Ultrafiltration versus usual care for hospitalized patients with heart failure: the Relief for Acutely Fluid-Overloaded Patients With Decompensated Congestive Heart Failure (RAPID-CHF) trial

    National Research Council Canada - National Science Library

    Bart, Bradley A; Boyle, Andrew; Bank, Alan J; Anand, Inder; Olivari, Maria Teresa; Kraemer, Mark; Mackedanz, Shari; Sobotka, Paul A; Schollmeyer, Mike; Goldsmith, Steven R

    2005-01-01

    ...) in patients admitted with decompensated congestive heart failure (CHF). Ultrafiltration for CHF is usually reserved for patients with renal failure or those unresponsive to pharmacologic management...

  12. Visualizing acoustical beats with a smartphones

    CERN Document Server

    Giménez, Marcos H; Castro-Palacio, Juan C; Gómez-Tejedor, José A; Monsoriu, Juan A

    2016-01-01

    In this work, a new Physics laboratory experiment on Acoustics beats is presented. We have designed a simple experimental setup to study superposition of sound waves of slightly different frequencies (acoustic beat). The microphone of a smartphone is used to capture the sound waves emitted by two equidistant speakers from the mobile which are at the same time connected to two AC generators. The smartphone is used as a measuring instrument. By means of a simple and free AndroidTM application, the sound level (in dB) as a function of time is measured and exported to a .csv format file. Applying common graphing analysis and a fitting procedure, the frequency of the beat is obtained. The beat frequencies as obtained from the smartphone data are compared with the difference of the frequencies set at the AC generator. A very good agreement is obtained being the percentage discrepancies within 1 %.

  13. Wearable Beat-to-Beat Blood Pressure Monitor

    Science.gov (United States)

    Lee, Yong Jin

    2015-01-01

    Linea Research Corporation has developed a wearable noninvasive monitor that provides continuous blood pressure and heart rate measurements in extreme environments. Designed to monitor the physiological effects of astronauts' prolonged exposure to reduced-gravity environments as well as the effectiveness of various countermeasures, the device offers wireless connectivity to allow transfer of both real-time and historical data. It can be modified to monitor the health status of astronaut crew members during extravehicular missions.

  14. Substrate stiffness-modulated registry phase correlations in cardiomyocytes map structural order to coherent beating

    Science.gov (United States)

    Dasbiswas, K.; Majkut, S.; Discher, D. E.; Safran, Samuel A.

    2015-01-01

    Recent experiments show that both striation, an indication of the structural registry in muscle fibres, as well as the contractile strains produced by beating cardiac muscle cells can be optimized by substrate stiffness. Here we show theoretically how the substrate rigidity dependence of the registry data can be mapped onto that of the strain measurements. We express the elasticity-mediated structural registry as a phase-order parameter using a statistical physics approach that takes the noise and disorder inherent in biological systems into account. By assuming that structurally registered myofibrils also tend to beat in phase, we explain the observed dependence of both striation and strain measurements of cardiomyocytes on substrate stiffness in a unified manner. The agreement of our ideas with experiment suggests that the correlated beating of heart cells may be limited by the structural order of the myofibrils, which in turn is regulated by their elastic environment.

  15. Alterações hemodinâmicas devido ao uso de estabilizadores em revascularização do miocárdio: estudo experimental Hemodynamic disorders related to beating heart surgery using cardiac stabilizers: experimental study

    Directory of Open Access Journals (Sweden)

    Pedro Paulo Martins de Oliveira

    2007-12-01

    -pump coronary artery bypass graft surgeries by means of both a suction device "Octopus" and a compression device (Speroni. METHODS: Ten swine underwent median sternotomy. Monitoring of ECG, continuous cardiac output, mean arterial pressure, mean pulmonary artery pressure, mean right and left atrial pressures, and right and left ventricular diastolic pressure were performed. Stroke volume and systemic vascular resistance were calculated. Both stabilizers were studied placed on three vessels: anterior interventricular branch, posterior interventricular branch, and marginal branch of the circumflex branch. Each animal was randomly designed to application regarding the type of stabilizer and the target artery. The measurements were carried out 5 minutes before and after the stabilizer application. RESULTS: In the anterior interventricular branch changes have occurred only with the compression device, thus reducing cardiac output, stroke volume, and mean arterial pressure, but increasing the systemic vascular resistance. In the posterior interventricular branch changes have occurred with the compression device (Speroni, reducing cardiac output and stroke volume, but increasing the heart rate. With the suction device (octopus there was an increase of both heart rate and systemic vascular resistance, but a decrease in stroke volume. In the marginal branch of the circumflex branch there was a decrease of cardiac output, stroke volume, and mean arterial pressure with both stabilizers. Also, there was a decrease in the mean pulmonary artery pressure and an increase in the mean right atrial pressure with the compression device (Speroni. CONCLUSION: Both stabilizers have caused hemodynamic changes. The compression device (Speroni is more associated with changes than the suction device (Octopus.

  16. The impact of binaural beats on creativity.

    Science.gov (United States)

    Reedijk, Susan A; Bolders, Anne; Hommel, Bernhard

    2013-01-01

    Human creativity relies on a multitude of cognitive processes, some of which are influenced by the neurotransmitter dopamine. This suggests that creativity could be enhanced by interventions that either modulate the production or transmission of dopamine directly, or affect dopamine-driven processes. In the current study we hypothesized that creativity can be influenced by means of binaural beats, an auditory illusion that is considered a form of cognitive entrainment that operates through stimulating neuronal phase locking. We aimed to investigate whether binaural beats affect creative performance at all, whether they affect divergent thinking, convergent thinking, or both, and whether possible effects may be mediated by the individual striatal dopamine level. Binaural beats were presented at alpha and gamma frequency. Participants completed a divergent and a convergent thinking task to assess two important functions of creativity, and filled out the Positive And Negative Affect Scale-mood State questionnaire (PANAS-S) and an affect grid to measure current mood. Dopamine levels in the striatum were estimated using spontaneous eye blink rates (EBRs). Results showed that binaural beats, regardless of the presented frequency, can affect divergent but not convergent thinking. Individuals with low EBRs mostly benefitted from alpha binaural beat stimulation, while individuals with high EBRs were unaffected or even impaired by both alpha and gamma binaural beats. This suggests that binaural beats, and possibly other forms of cognitive entrainment, are not suited for a one-size-fits-all approach, and that individual cognitive-control systems need to be taken into account when studying cognitive enhancement methods.

  17. The impact of binaural beats on creativity

    Directory of Open Access Journals (Sweden)

    Susan A. Reedijk

    2013-11-01

    Full Text Available Human creativity relies on a multitude of cognitive processes, some of which are influenced by the neurotransmitter dopamine. This suggests that creativity could be enhanced by interventions that either modulate the production or transmission of dopamine directly, or affect dopamine-driven processes. In the current study we hypothesized that creativity can be influenced by means of binaural beats, an auditory illusion that is considered a form of cognitive entrainment that operates through stimulating neuronal phase locking. We aimed to investigate whether binaural beats affect creative performance at all, whether they affect divergent thinking, convergent thinking, or both, and whether possible effects may be mediated by the individual striatal dopamine level. Binaural beats were presented at alpha and gamma frequency. Participants completed a divergent and a convergent thinking task to assess two important functions of creativity, and filled out the Positive And Negative Affect Scale – mood State questionnaire (PANAS-S and affect grid to measure current mood. Dopamine levels in the striatum were estimated using spontaneous eye blink rates (EBRs. Results showed that binaural beats, regardless of the presented frequency, can affect divergent but not convergent thinking. Individuals with low EBRs mostly benefitted from alpha binaural beat stimulation, while individuals with high EBR were unaffected or even impaired by both alpha and gamma binaural beats. This suggests that binaural beats, and possibly other forms of cognitive entrainment, are not suited for a one-size-fits-all approach, and that individual cognitive-control systems need to be taken into account when studying cognitive enhancement methods.

  18. Nonlinear evolution of the plasma beat wave: Compressing the laser beat notes via electromagnetic cascading.

    Science.gov (United States)

    Kalmykov, Serguei; Shvets, Gennady

    2006-04-01

    The near-resonant beat wave excitation of an electron plasma wave (EPW) can be employed for generating the trains of few-femtosecond electromagnetic (EM) pulses in rarefied plasmas. The EPW produces a comoving index grating that induces a laser phase modulation at the difference frequency. As a result, the cascade of sidebands red and blue shifted by integer multiples of the beat frequency is generated in the laser spectrum. The bandwidth of the phase-modulated laser is proportional to the product of the plasma length, laser wavelength, and amplitude of the electron density perturbation. When the beat frequency is lower than the electron plasma frequency, the redshifted spectral components are advanced in time with respect to the blueshifted ones near the center of each laser beat note. The group velocity dispersion of plasma compresses so chirped beat notes to a few-laser-cycle duration thus creating a train of sharp EM spikes with the beat periodicity. Depending on the plasma and laser parameters, chirping and compression can be implemented either concurrently in the same, or sequentially in different plasmas. Evolution of the laser beat wave and electron density perturbations is described in time and one spatial dimension in a weakly relativistic approximation. Using the compression effect, we demonstrate that the relativistic bistability regime of the EPW excitation [G. Shvets, Phys. Rev. Lett. 93, 195004 (2004)] can be achieved with the initially subthreshold beat wave pulse.

  19. BeatBox-HPC simulation environment for biophysically and anatomically realistic cardiac electrophysiology.

    Science.gov (United States)

    Antonioletti, Mario; Biktashev, Vadim N; Jackson, Adrian; Kharche, Sanjay R; Stary, Tomas; Biktasheva, Irina V

    2017-01-01

    The BeatBox simulation environment combines flexible script language user interface with the robust computational tools, in order to setup cardiac electrophysiology in-silico experiments without re-coding at low-level, so that cell excitation, tissue/anatomy models, stimulation protocols may be included into a BeatBox script, and simulation run either sequentially or in parallel (MPI) without re-compilation. BeatBox is a free software written in C language to be run on a Unix-based platform. It provides the whole spectrum of multi scale tissue modelling from 0-dimensional individual cell simulation, 1-dimensional fibre, 2-dimensional sheet and 3-dimensional slab of tissue, up to anatomically realistic whole heart simulations, with run time measurements including cardiac re-entry tip/filament tracing, ECG, local/global samples of any variables, etc. BeatBox solvers, cell, and tissue/anatomy models repositories are extended via robust and flexible interfaces, thus providing an open framework for new developments in the field. In this paper we give an overview of the BeatBox current state, together with a description of the main computational methods and MPI parallelisation approaches.

  20. Habituation of parasympathetic-mediated heart rate responses to recurring acoustic startle.

    Science.gov (United States)

    Chen, Kuan-Hua; Aksan, Nazan; Anderson, Steven W; Grafft, Amanda; Chapleau, Mark W

    2014-01-01

    Startle habituation is a type of implicit and automatic emotion regulation. Diminished startle habituation is linked to several psychiatric or neurological disorders. Most previous studies quantified startle habituation by assessing skin conductance response (SCR; reflecting sympathetic-mediated sweating), eye-blink reflex, or motor response. The habituation of parasympathetic-mediated heart rate responses to recurrent startle stimuli is not well understood. A variety of methods and metrics have been used to quantify parasympathetic activity and its effects on the heart. We hypothesized that these different measures reflect unique psychological and physiological processes that may habituate differently during repeated startle stimuli. We measured cardiac inter-beat intervals (IBIs) to recurring acoustic startle probes in 75 eight year old children. Eight acoustic stimuli of 500 ms duration were introduced at intervals of 15-25 s. Indices of parasympathetic effect included: (1) the initial rapid decrease in IBI post-startle mediated by parasympathetic inhibition (PI); (2) the subsequent IBI recovery mediated by parasympathetic reactivation (PR); (3) rapid, beat-to-beat heart rate variability (HRV) measured from the first seven IBIs following each startle probe. SCR and motor responses to startle were also measured. Results showed that habituation of PR (IBI recovery and overshoot) and SCRs were rapid and robust. In addition, changes in PR and SCR were significantly correlated. In contrast, habituation of PI (the initial decrease in IBI) was slower and relatively modest. Measurement of rapid HRV provided an index reflecting the combination of PI and PR. We conclude that different measures of parasympathetic-mediated heart rate responses to repeated startle probes habituate in a differential manner.

  1. High beat-to-beat blood pressure variability in atrial fibrillation compared to sinus rhythm.

    Science.gov (United States)

    Olbers, Joakim; Gille, Adam; Ljungman, Petter; Rosenqvist, Mårten; Östergren, Jan; Witt, Nils

    2018-02-07

    Atrial fibrillation (AF) is associated with an increased risk for cardiovascular morbidity and mortality, not entirely explained by thromboembolism. The underlying mechanisms for this association are largely unknown. Similarly, high blood pressure (BP) increases the risk for cardiovascular events. Despite this the interplay between AF and BP is insufficiently studied. The purpose of this study was to examine and quantify the beat-to-beat blood pressure variability in patients with AF in comparison to a control group of patients with sinus rhythm. We studied 33 patients - 21 in atrial fibrillation and 12 in sinus rhythm - undergoing routine coronary angiography. Invasive blood pressure was recorded at three locations: radial artery, brachial artery and ascending aorta. Blood pressure variability, defined as average beat-to-beat blood pressure difference, was calculated for systolic and diastolic blood pressure at each site. We observed a significant difference (p blood pressure variability between the atrial fibrillation and sinus rhythm groups at all locations. Systolic blood pressure variability roughly doubled in the atrial fibrillation group compared to the sinus rhythm group (4.9 and 2.4 mmHg respectively). Diastolic beat-to-beat blood pressure variability was approximately 6 times as high in the atrial fibrillation group compared to the sinus rhythm group (7.5 and 1.2 mmHg respectively). No significant difference in blood pressure variability was seen between measurement locations. Beat-to-beat blood pressure variability in patients with atrial fibrillation was substantially higher than in patients with sinus rhythm. Hemodynamic effects of this beat-to-beat variation in blood pressure may negatively affect vascular structure and function, which may contribute to the increased cardiovascular morbidity and mortality seen in patients with atrial fibrillation.

  2. Pharmacological activation of rapid delayed rectifier potassium current suppresses bradycardia-induced triggered activity in the isolated guinea pig heart

    DEFF Research Database (Denmark)

    Hansen, Rie Schultz; Olesen, Søren-Peter; Grunnet, Morten

    2007-01-01

    arrhythmias. We present here data that support that NS3623 affects native I(Kr) and report the effects that activating this potassium current have in the intact guinea pig heart. In Langendorff-perfused hearts, the compound showed a concentration-dependent shortening of action potential duration, which...... was also detected as concentration-dependent shorter QT intervals. There was no sign of action potential triangulation or reverse use dependence. NS3623 decreased QT variability and distinctly decreased the occurrence of extrasystoles in the acutely bradypaced hearts. Taken together, the present data...

  3. Acoustical sensing of cardiomyocyte cluster beating

    Energy Technology Data Exchange (ETDEWEB)

    Tymchenko, Nina; Kunze, Angelika [Dept. of Applied Physics, Chalmers University of Technology, 412 96 Göteborg (Sweden); Dahlenborg, Kerstin [Cellectis, 413 46 Göteborg (Sweden); Svedhem, Sofia, E-mail: sofia.svedhem@chalmers.se [Dept. of Applied Physics, Chalmers University of Technology, 412 96 Göteborg (Sweden); Steel, Daniella [Cellectis, 413 46 Göteborg (Sweden)

    2013-06-14

    Highlights: •An example of the application of QCM-D to live cell studies. •Detection of human pluripotent stem cell-derived cardiomyocyte cluster beating. •Clusters were studied in a thin liquid film and in a large liquid volume. •The QCM-D beating profile provides an individual fingerprint of the hPS-CMCs. -- Abstract: Spontaneously beating human pluripotent stem cell-derived cardiomyocytes clusters (CMCs) represent an excellent in vitro tool for studies of human cardiomyocyte function and for pharmacological cardiac safety assessment. Such testing typically requires highly trained operators, precision plating, or large cell quantities, and there is a demand for real-time, label-free monitoring of small cell quantities, especially rare cells and tissue-like structures. Array formats based on sensing of electrical or optical properties of cells are being developed and in use by the pharmaceutical industry. A potential alternative to these techniques is represented by the quartz crystal microbalance with dissipation monitoring (QCM-D) technique, which is an acoustic surface sensitive technique that measures changes in mass and viscoelastic properties close to the sensor surface (from nm to μm). There is an increasing number of studies where QCM-D has successfully been applied to monitor properties of cells and cellular processes. In the present study, we show that spontaneous beating of CMCs on QCM-D sensors can be clearly detected, both in the frequency and the dissipation signals. Beating rates in the range of 66–168 bpm for CMCs were detected and confirmed by simultaneous light microscopy. The QCM-D beating profile was found to provide individual fingerprints of the hPS-CMCs. The presented results point towards acoustical assays for evaluation cardiotoxicity.

  4. Beat-to-beat T-wave alternans detection using the Ensemble Empirical Mode Decomposition method.

    Science.gov (United States)

    Hasan, Muhammad A; Chauhan, Vijay S; Krishnan, Sridhar

    2016-10-01

    T-wave alternans (TWA) is defined as a consistent variation in the repolarization morphology that repeats on every other beat. This study aimed to evaluate beat-to-beat TWA detection using the Ensemble EMD (EEMD) method. A total of 108 recordings of standard 12-lead ECGs of 69 healthy subjects (17 females, 42±18 years; 52 males, 40±13 years) and 39 cardiac-condition patients (ischemic cardiomyopathy; ICM and dilated cardiomyopathy; DCM) with left ventricular ejection fractions (LVEF) ≤40% were studied. We first determined the QT interval of ECG via a template matching algorithm. Then, beat-to-beat T-waves were extracted to quantify beat-to-beat TWA. The EEMD method was applied to the T-wave time series to decompose them into a set of intrinsic mode functions (IMFs). The instantaneous frequency was measured by performing the Hilbert transform on the selected IMF for extracting the features. Four different classifiers were applied to the extracted features to assess and classify the existence of TWA in the ECG signal. In the simulation study, the global classifier worked better than the subject-based classifier for detecting alternans in the T-waves. In addition, the average accuracy and sensitivity for detecting TWA were greater than 80%. In the real Holter ECG data obtained from Toronto General Hospital, the Ensemble classifier had higher classification accuracy, 74%, than other classifiers and a positive predictive value of 100%. In conclusion, the proposed Ensemble EMD method with Ensemble classifier can be utilized for detecting beat-to-beat TWA in the ECG signal. Copyright © 2016 Elsevier Ltd. All rights reserved.

  5. Rapid negative inotropic effect induced by TNF-α in rat heart perfused related to PKC activation.

    Science.gov (United States)

    Jude, B; Vetel, S; Giroux-Metges, M A; Pennec, J P

    2017-11-29

    Myocardial depression, frequently observed in septic shock, is mediated by circulating molecules such as cytokines. TNF-α appears to be the most important pro-inflammatory cytokine released during the early phase of a septic shock. It was previously shown that TNF-α had a negative inotropic effect on myocardium. Now, the aim of this study was to investigate the effects of the activation of PKC by TNF-α on heart function, and to determine if this cytokine could induce a decrease of membrane excitability. Isolated rat hearts (n = 6) were perfused with Tyrode solution containing TNF-α at 20 ng/ml during 30 min by using a Langendorff technique. Expressions of PKC-α and PKC-ε were analysed by western blot on membrane and cytosol proteins extracted from ventricular myocardium. Patch clamp was performed on freshly isolated cardiomyocytes (n = 8). Compared to control situation, 30 min of TNF-α perfusion led to cardiac dysfunction with a decrease of the heart rate (-83%), the force (-20%) and speed of relaxation (-18%) and the coronary flow (-25%). This is associated with an activation and a membrane targeting of both PKC-α and PKC-ε isoforms in ventricle with respectively +123% and +54% compared to control hearts. Nevertheless, TNF-α had no significant effect on voltage-gated sodium current (109.0%+/- 12.5) after addition of the cytokine when compared to control. These results showed that TNF-α had a negative inotropic effect on the isolated rat heart and can induce PKC activation leading to an impaired contractility of the heart. However the early heart dysfunction induced by the cytokine was not associated to a decrease of cardiomyocytes membrane excitability as it has been evidenced in skeletal muscle fibres. Copyright © 2017 Elsevier Ltd. All rights reserved.

  6. Behind the scenes of GS: CERN’s beating heart

    CERN Multimedia

    Antonella Del Rosso

    2014-01-01

    Founded at the same time as CERN, the library has followed, and sometimes even moved ahead of, the changes in the Organization. Today, far from being a simple book depository, the Scientific Information Service (SIS) that manages CERN's library is increasingly digitising its material and investing in innovative projects, such as Open Access.   Ever since it was set up in Building 52 on 1 September 1957, the library has played a vital role in the Organization.  “Our only official task is to provide a complete list of the publications by CERN researchers, but, in fact, this place is the memory bank of the whole Laboratory,” emphasises Tullio Basaglia, head of the Library Section within SIS.  “The role of the library and archives is to preserve, document and disseminate the knowledge produced at CERN.” Sixty years after its creation, the library today contains 90,000 books, two thirds of which are available in a digital ...

  7. The new heart of the PS is beating strongly

    CERN Document Server

    Corinne Pralavorio

    2011-01-01

    The PS has resumed operation with a brand new electrical power system called POPS; this enormous system comprising power electronics and capacitors is crucial because if it broke down practically no particles would be able to circulate at CERN. As soon as it started, POPS passed all the tests with flying colours and is now pulsing at full power.   The new PS power system is made up of 6 containers, each with 60 tonnes of capacitors and 8 power converters. The date 11/02/11 will always be remembered with affection by the engineers in the Electrical Power Converters Group. At 11:11 in the morning (no joke), the first beams powered by the new system began to circulate in the PS. The cutely-named POPS (POwer for PS) took over from the old rotating machine that had been working since 1968. From now on it will be POPS that supplies the PS main magnets with the electrical pulses needed to accelerate the beams for the LHC and all CERN's other facilities. The system is crucial as the PS is one of the lyn...

  8. Truthfulness in transplantation: non-heart-beating organ donation

    Directory of Open Access Journals (Sweden)

    Potts Michael

    2007-08-01

    Full Text Available Abstract The current practice of organ transplantation has been criticized on several fronts. The philosophical and scientific foundations for brain death criteria have been crumbling. In addition, donation after cardiac death, or non-heartbeating-organ donation (NHBD has been attacked on grounds that it mistreats the dying patient and uses that patient only as a means to an end for someone else's benefit. Verheijde, Rady, and McGregor attack the deception involved in NHBD, arguing that the donors are not dead and that potential donors and their families should be told that is the case. Thus, they propose abandoning the dead donor rule and allowing NHBD with strict rules concerning adequate informed consent. Such honesty about NHBD should be welcomed. However, NHBD violates a fundamental end of medicine, nonmaleficience, "do no harm." Physicians should not be harming or killing patients, even if it is for the benefit of others. Thus, although Verheijde and his colleages should be congratulated for calling for truthfulness about NHBD, they do not go far enough and call for an elimination of such an unethical procedure from the practice of medicine.

  9. [A case of left ventricular pseudoaneurysm with severe cardiac failure and premature ventricular beats].

    Science.gov (United States)

    Nakmura, M; Kazui, T; Takagi, N; Harada, H; Yokoyama, H; Okamoto, F; Komatsu, S

    1989-10-01

    A surgically successful case of left ventricular pseudoaneurysm 10 years after an acute myocardial infarction was reported. A 63-year-old man had an acute inferior myocardial infarction 10 years ago. Recently congestive heart failure and premature ventricular beats developed. He was diagnosed as a left ventricular pseudoaneurysm by echocardiogram, CT scan, and left ventriculogram. After the operation, the symptoms diminished and improvement of left ventricular function was observed. A brief review of the literature is given.

  10. Newborn infants detect the beat in music

    NARCIS (Netherlands)

    Winkler, I.; Háden, G.P.; Ladinig, O.; Sziller, I.; Honing, H.

    2009-01-01

    To shed light on how humans can learn to understand music, we need to discover what the perceptual capabilities with which infants are born. Beat induction, the detection of a regular pulse in an auditory signal, is considered a fundamental human trait that, arguably, played a decisive role in the

  11. Predictive value of beat-to-beat QT variability index across the continuum of left ventricular dysfunction: competing risks of noncardiac or cardiovascular death and sudden or nonsudden cardiac death.

    Science.gov (United States)

    Tereshchenko, Larisa G; Cygankiewicz, Iwona; McNitt, Scott; Vazquez, Rafael; Bayes-Genis, Antoni; Han, Lichy; Sur, Sanjoli; Couderc, Jean-Philippe; Berger, Ronald D; de Luna, Antoni Bayes; Zareba, Wojciech

    2012-08-01

    The goal of the present study was to determine the predictive value of beat-to-beat QT variability in heart failure patients across the continuum of left ventricular dysfunction. Beat-to-beat QT variability index (QTVI), log-transformed heart rate variance, normalized QT variance, and coherence between heart rate variability and QT variability have been measured at rest during sinus rhythm in 533 participants of the Muerte Subita en Insuficiencia Cardiaca heart failure study (mean age, 63.1±11.7; men, 70.6%; left ventricular ejection fraction >35% in 254 [48%]) and in 181 healthy participants from the Intercity Digital Electrocardiogram Alliance database. During a median of 3.7 years of follow-up, 116 patients died, 52 from sudden cardiac death (SCD). In multivariate competing risk analyses, the highest QTVI quartile was associated with cardiovascular death (subhazard ratio, 1.67 [95% CI, 1.14-2.47]; P=0.009) and, in particular, with non-SCD (subhazard ratio, 2.91 [1.69-5.01]; P<0.001). Elevated QTVI separated 97.5% of healthy individuals from subjects at risk for cardiovascular (subhazard ratio, 1.57 [1.04-2.35]; P=0.031) and non-SCD in multivariate competing risk model (subhazard ratio, 2.58 [1.13-3.78]; P=0.001). No interaction between QTVI and left ventricular ejection fraction was found. QTVI predicted neither noncardiac death (P=0.546) nor SCD (P=0.945). Decreased heart rate variability rather than increased QT variability was the reason for increased QTVI in the present study. Increased QTVI because of depressed heart rate variability predicts cardiovascular mortality and non-SCD but neither SCD nor extracardiac mortality in heart failure across the continuum of left ventricular dysfunction. Abnormally augmented QTVI separates 97.5% of healthy individuals from heart failure patients at risk.

  12. Heart transplantation.

    Science.gov (United States)

    Cheng, Allen; Slaughter, Mark S

    2014-08-01

    Heart failure remains a major global problem with approximately 6 million individuals suffering from heart failure in the United States alone. The surgical technique of heart transplantation, popularized by Dr. Norman Shumway, has led to its success and currently remains the best treatment options for patients with end-stage. However, with the continued limitation of donor organs and the rapid development of ventricular assist device technology, the number of patients bridged to transplant with mechanical circulatory support has increased significantly. This has created some new technical challenges for heart transplantation. Therefore, it is now important to be familiar with multiple new technical challenges associated with the surgical techniques of heart transplantation with an ultimate goal in reducing donor heart ischemic time, recipient cardiopulmonary bypass time and post-operative complications. In this review, we described our technique of heart transplantation including the timing of the operation, recipient cardiectomy and donor heart implantation.

  13. Do Preferred Beat Rate and Entrainment to the Beat Have a Common Origin in Movement?

    Directory of Open Access Journals (Sweden)

    Laurel J. Trainor

    2007-01-01

    Full Text Available The idea that beat induction derives from body movement is attractive, but until recently unequivocal empirical evidence of such a linkage has been elusive. Todd et al. (2007 provide evidence that individual differences in locomotion affect preferred beat rate, and Phillips-Silver & Trainor (2005, 2007, under review show that metrical interpretation is affected by movement. These studies examine different aspects of rhythm processing, but together provide converging evidence for pervasive movement/auditory interactions.

  14. Using Complexity Metrics With R-R Intervals and BPM Heart Rate Measures

    DEFF Research Database (Denmark)

    Wallot, Sebastian; Fusaroli, Riccardo; Tylén, Kristian

    2013-01-01

    on variability of the data, different choices regarding the kind of measures can have a substantial impact on the results. In this article we compare linear and non-linear statistics on two prominent types of heart beat data, beat-to-beat intervals (R-R interval) and beats-per-minute (BPM). As a proof...... of interpersonal coordination. However, there is no consensus about which measurements and analytical tools are most appropriate in mapping the temporal dynamics of heart rate and quite different metrics are reported in the literature. As complexity metrics of heart rate variability depend critically......-of-concept, we employ a simple rest-exercise-rest task and show that non-linear statistics – fractal (DFA) and recurrence (RQA) analyses – reveal information about heart beat activity above and beyond the simple level of heart rate. Non-linear statistics unveil sustained post-exercise effects on heart rate...

  15. From music-beat to heart-beat: a journey in the complex interactions between music, brain and heart.

    Science.gov (United States)

    Cervellin, Gianfranco; Lippi, Giuseppe

    2011-08-01

    Although the potential influence of music in eliciting organic reactions has been appreciated since the ancient Assyrian and Greek cultures, its relationship with body responses has been believed for long to belong to the field of magic. Growing experimental evidence now attests that some kind of music might indeed modulate several cardiac and neurological functions, as well as trigger biochemical measurable stress-reducing effects in certain individuals, mostly depending on their subjective musical education. On this basis, music has been increasingly used as a therapeutic tool in the treatment of different diseases in healthy and ill subjects over recent years (e.g., the so called "Mozart effect"), although the underlying scientific background is still poorly understood. The aim of this article is to review the current scientific evidences about the complex and multifaceted interactions between music and human biology. Copyright © 2011 European Federation of Internal Medicine. Published by Elsevier B.V. All rights reserved.

  16. Heart rate variability during cycloergometric exercise or judo wrestling eliciting the same heart rate level.

    Science.gov (United States)

    Cottin, François; Durbin, François; Papelier, Yves

    2004-03-01

    This study compared heart rate variability (HRV) in ten male judokas between two types of exercise eliciting the same near-maximal average heart rate (HR): judo wrestling vs. cycloergometric bout. Beat-to-beat RR intervals were recorded during (1) a 4-min judo randori (wrestling); (2) a 4-min cycloergometric exercise eliciting maximal oxygen consumption (VO(2MAX)). Time series were analyzed both by short term Fourier transform (STFT) and Poincaré plot (PP). The main results are as follows. First, despite the fact that the same maximal HR was reached during the two exercises, the spectral energy computed from the judo recordings was significantly higher than that recorded from the cycloergometric exercise. Second, according to the PP index of rapid HRV (SD1), the high-frequency spectral energy (HF) was significantly higher during judo than cycloergometric exercise as well. Third, judo spectra show chaotic harmonics in place of the precise HF peak observed during cycloergometric exercise. Fourth, the respective parts of normalized LFn and HFn are not different between the two exercise modes, suggesting that autonomic control during severe exercise cannot depend on the type of exercise. In conclusion, this study shows that it is possible, according to the observed kind of variability from RR time series, to differentiate between two types of effort: steady-state dynamic exercise or conversely exercise made of both isometric and irregular dynamic efforts (wrestling, collective sports, and others).

  17. Relationship between age and location of the apex beat among ...

    African Journals Online (AJOL)

    Apex beat location in the intercostal space was determined and distance of apex beat from the midline, midclavicular line and nipple lines were measured. The measured distances were related to age using linear regression and Pearson correlation. Results: The mean distance of apex beat from the midline from birth to 10 ...

  18. Beat Gestures Modulate Auditory Integration in Speech Perception

    Science.gov (United States)

    Biau, Emmanuel; Soto-Faraco, Salvador

    2013-01-01

    Spontaneous beat gestures are an integral part of the paralinguistic context during face-to-face conversations. Here we investigated the time course of beat-speech integration in speech perception by measuring ERPs evoked by words pronounced with or without an accompanying beat gesture, while participants watched a spoken discourse. Words…

  19. Peak heart rates at extreme altitudes

    DEFF Research Database (Denmark)

    Lundby, C; Van Hall, Gerrit

    2001-01-01

    We have measured maximal heart rate during a graded maximal bicycle exercise test to exhaustion in five healthy climbers before and during an expedition to Mt. Everest. Maximal heart rates at sea level were 186 (177-204) beats/min(-1) at sea level and 170 (169-182) beats/min(-1) with acute hypoxia....... After 1, 4 and 6 weeks of acclimatization to 5400 m, maximal heart rates were 155 (135-182), 158 (144-182), and 155 (140-183) beats/min(-1), respectively. Heart rates of two of the climbers were measured during their attempt to reach the summit of Mt. Everest without the use of supplemental oxygen....... The peak heart rates at 8,750 m for the two climbers were 142 and 144 beats/min(-1), which were similar to their maximal heart rates during exhaustive bicycle exercise at 5,400 m, the values being 144 and 148 beats/min(-1), respectively. The peak heart rates at 8,750 m are in agreement with other field...

  20. Fetal Intelligent Navigation Echocardiography (FINE): a novel method for rapid, simple, and automatic examination of the fetal heart.

    Science.gov (United States)

    Yeo, Lami; Romero, Roberto

    2013-09-01

    To describe a novel method (Fetal Intelligent Navigation Echocardiography (FINE)) for visualization of standard fetal echocardiography views from volume datasets obtained with spatiotemporal image correlation (STIC) and application of 'intelligent navigation' technology. We developed a method to: 1) demonstrate nine cardiac diagnostic planes; and 2) spontaneously navigate the anatomy surrounding each of the nine cardiac diagnostic planes (Virtual Intelligent Sonographer Assistance (VIS-Assistance®)). The method consists of marking seven anatomical structures of the fetal heart. The following echocardiography views are then automatically generated: 1) four chamber; 2) five chamber; 3) left ventricular outflow tract; 4) short-axis view of great vessels/right ventricular outflow tract; 5) three vessels and trachea; 6) abdomen/stomach; 7) ductal arch; 8) aortic arch; and 9) superior and inferior vena cava. The FINE method was tested in a separate set of 50 STIC volumes of normal hearts (18.6-37.2 weeks of gestation), and visualization rates for fetal echocardiography views using diagnostic planes and/or VIS-Assistance® were calculated. To examine the feasibility of identifying abnormal cardiac anatomy, we tested the method in four cases with proven congenital heart defects (coarctation of aorta, tetralogy of Fallot, transposition of great vessels and pulmonary atresia with intact ventricular septum). In normal cases, the FINE method was able to generate nine fetal echocardiography views using: 1) diagnostic planes in 78-100% of cases; 2) VIS-Assistance® in 98-100% of cases; and 3) a combination of diagnostic planes and/or VIS-Assistance® in 98-100% of cases. In all four abnormal cases, the FINE method demonstrated evidence of abnormal fetal cardiac anatomy. The FINE method can be used to visualize nine standard fetal echocardiography views in normal hearts by applying 'intelligent navigation' technology to STIC volume datasets. This method can simplify

  1. Is the stroke volume during post-ectopic beat associated with ventricular premature complex-related symptoms?

    Science.gov (United States)

    Gwag, Hye Bin; Kim, Eun Kyoung; Hwang, Jin Kyung; Park, Seung-Jung; On, Young Keun; Kim, June Soo; Park, Kyoung-Min

    2017-07-03

    This study aimed to investigate if increased stroke volume (SV) after a ventricular premature complex (VPC) was related to VPC-related symptoms. We selected patients having an isolated VPC during echocardiography from a prospective registry that included patients with a structurally normal heart and 24-h VPC >1%. Patients were divided into two groups according to the presence or absence of VPC-related symptoms (skipped beat or palpitation) when VPC occurred. Left ventricular (LV) volumes and time-velocity integral (TVI) at the LV outflow tract were measured during the preceding sinus beat, VPC, and post-ectopic sinus beat. Percent LV SV of the VPC and post-ectopic sinus beat were calculated by dividing each SV by the SV of the preceding sinus beat. A total of 47 patients were eligible. Most patients had VPC with left bundle branch block morphology and inferior axis. Patients in the symptom (+) group had a significantly lower SV, %LV SV, and TVI during post-ectopic sinus beat than those in the symptom (-) group. The sum of SVs during VPC and post-ectopic beat was significantly lower in symptomatic patients than non-symptomatic patients (103.4 mL vs. 125.1 mL, P = 0.02), while the sum of %LV SVs during VPC and post-ectopic beat tended to be lower in patients with symptoms than those without symptoms (P = 0.08). The sum of %LV SVs during VPC and post-VPC was positively correlated with coupling interval (CI) and CI ratio. Ventricular premature complex-related symptoms may not be associated with the amount of post-VPC SV.

  2. Mechanisms of Intrinsic Beating Variability in Cardiac Cell Cultures and Model Pacemaker Networks

    Science.gov (United States)

    Ponard, Julien G. C.; Kondratyev, Aleksandar A.; Kucera, Jan P.

    2007-01-01

    Heart rate variability (HRV) exhibits fluctuations characterized by a power law behavior of its power spectrum. The interpretation of this nonlinear HRV behavior, resulting from interactions between extracardiac regulatory mechanisms, could be clinically useful. However, the involvement of intrinsic variations of pacemaker rate in HRV has scarcely been investigated. We examined beating variability in spontaneously active incubating cultures of neonatal rat ventricular myocytes using microelectrode arrays. In networks of mathematical model pacemaker cells, we evaluated the variability induced by the stochastic gating of transmembrane currents and of calcium release channels and by the dynamic turnover of ion channels. In the cultures, spontaneous activity originated from a mobile focus. Both the beat-to-beat movement of the focus and beat rate variability exhibited a power law behavior. In the model networks, stochastic fluctuations in transmembrane currents and stochastic gating of calcium release channels did not reproduce the spatiotemporal patterns observed in vitro. In contrast, long-term correlations produced by the turnover of ion channels induced variability patterns with a power law behavior similar to those observed experimentally. Therefore, phenomena leading to long-term correlated variations in pacemaker cellular function may, in conjunction with extracardiac regulatory mechanisms, contribute to the nonlinear characteristics of HRV. PMID:17325022

  3. Autonomic heart-rate control in response to standing in toxemic and normotensive primigravid pregnancies

    NARCIS (Netherlands)

    WJ Jaspers; PA de Jong; PJ Kurver; MD E.J.M. Wouters

    1984-01-01

    Heart-rate changes after transition from a supine to a standing posture were measured in 12 hypertensive and 12 normotensive primigravid women, in their last trimester of gestation. The subjects beat-to-beat heart-rate (HR) changes were recorded on both an ordinary cardiotocograph and on magnetic

  4. The Impact of Monaural Beat Stimulation on Anxiety and Cognition

    Directory of Open Access Journals (Sweden)

    Leila Chaieb

    2017-05-01

    Full Text Available Application of auditory beat stimulation has been speculated to provide a promising new tool with which to alleviate symptoms of anxiety and to enhance cognition. In spite of reportedly similar EEG effects of binaural and monaural beats, data on behavioral effects of monaural beats are still lacking. Therefore, we examined the impact of monaural beat stimulation on anxiety, mood and memory performance. We aimed to target states related to anxiety levels and general well-being, in addition to long-term and working memory processes, using monaural beats within the range of main cortical rhythms. Theta (6 Hz, alpha (10 Hz and gamma (40 Hz beat frequencies, as well as a control stimulus were applied to healthy participants for 5 min. After each stimulation period, participants were asked to evaluate their current mood state and to perform cognitive tasks examining long-term and working memory processes, in addition to a vigilance task. Monaural beat stimulation was found to reduce state anxiety. When evaluating responses for the individual beat frequencies, positive effects on state anxiety were observed for all monaural beat conditions compared to control stimulation. Our results indicate a role for monaural beat stimulation in modulating state anxiety and are in line with previous studies reporting anxiety-reducing effects of auditory beat stimulation.

  5. aBEAT: a toolbox for consistent analysis of longitudinal adult brain MRI.

    Directory of Open Access Journals (Sweden)

    Yakang Dai

    Full Text Available Longitudinal brain image analysis is critical for revealing subtle but complex structural and functional changes of brain during aging or in neurodevelopmental disease. However, even with the rapid increase of clinical research and trials, a software toolbox dedicated for longitudinal image analysis is still lacking publicly. To cater for this increasing need, we have developed a dedicated 4D Adult Brain Extraction and Analysis Toolbox (aBEAT to provide robust and accurate analysis of the longitudinal adult brain MR images. Specially, a group of image processing tools were integrated into aBEAT, including 4D brain extraction, 4D tissue segmentation, and 4D brain labeling. First, a 4D deformable-surface-based brain extraction algorithm, which can deform serial brain surfaces simultaneously under temporal smoothness constraint, was developed for consistent brain extraction. Second, a level-sets-based 4D tissue segmentation algorithm that incorporates local intensity distribution, spatial cortical-thickness constraint, and temporal cortical-thickness consistency was also included in aBEAT for consistent brain tissue segmentation. Third, a longitudinal groupwise image registration framework was further integrated into aBEAT for consistent ROI labeling by simultaneously warping a pre-labeled brain atlas to the longitudinal brain images. The performance of aBEAT has been extensively evaluated on a large number of longitudinal MR T1 images which include normal and dementia subjects, achieving very promising results. A Linux-based standalone package of aBEAT is now freely available at http://www.nitrc.org/projects/abeat.

  6. aBEAT: a toolbox for consistent analysis of longitudinal adult brain MRI.

    Science.gov (United States)

    Dai, Yakang; Wang, Yaping; Wang, Li; Wu, Guorong; Shi, Feng; Shen, Dinggang

    2013-01-01

    Longitudinal brain image analysis is critical for revealing subtle but complex structural and functional changes of brain during aging or in neurodevelopmental disease. However, even with the rapid increase of clinical research and trials, a software toolbox dedicated for longitudinal image analysis is still lacking publicly. To cater for this increasing need, we have developed a dedicated 4D Adult Brain Extraction and Analysis Toolbox (aBEAT) to provide robust and accurate analysis of the longitudinal adult brain MR images. Specially, a group of image processing tools were integrated into aBEAT, including 4D brain extraction, 4D tissue segmentation, and 4D brain labeling. First, a 4D deformable-surface-based brain extraction algorithm, which can deform serial brain surfaces simultaneously under temporal smoothness constraint, was developed for consistent brain extraction. Second, a level-sets-based 4D tissue segmentation algorithm that incorporates local intensity distribution, spatial cortical-thickness constraint, and temporal cortical-thickness consistency was also included in aBEAT for consistent brain tissue segmentation. Third, a longitudinal groupwise image registration framework was further integrated into aBEAT for consistent ROI labeling by simultaneously warping a pre-labeled brain atlas to the longitudinal brain images. The performance of aBEAT has been extensively evaluated on a large number of longitudinal MR T1 images which include normal and dementia subjects, achieving very promising results. A Linux-based standalone package of aBEAT is now freely available at http://www.nitrc.org/projects/abeat.

  7. Applicability and performance of heart rate variability methods

    NARCIS (Netherlands)

    Haaksma, J; Brouwer, J; Dijk, WA; van den Berg, M; Takens, F; Dassen, WRM; Murray, A

    2003-01-01

    Heart Rate Variability (HRV) may be measured using different measurement techniques. Almost all of these techniques deal with ectopic beats. Either these beats are excluded from the analysis or they are required. To access the functional character and easiness of use of several HRV techniques we

  8. Appropriate threshold levels of cardiac beat-to-beat variation in semi-automatic analysis of equine ECG recordings

    DEFF Research Database (Denmark)

    Madsen, Mette Flethøj; Kanters, Jørgen K.; Pedersen, Philip Juul

    2016-01-01

    Background: Although premature beats are a matter of concern in horses, the interpretation of equine ECG recordings is complicated by a lack of standardized analysis criteria and a limited knowledge of the normal beat-to-beat variation of equine cardiac rhythm. The purpose of this study...... was to determine the appropriate threshold levels of maximum acceptable deviation of RR intervals in equine ECG analysis, and to evaluate a novel two-step timing algorithm by quantifying the frequency of arrhythmias in a cohort of healthy adult endurance horses. Results: Beat-to-beat variation differed......, range 1–24). Conclusions: Beat-to-beat variation of equine cardiac rhythm varies according to HR, and threshold levels in equine ECG analysis should be adjusted accordingly. Standardization of the analysis criteria will enable comparisons of studies and follow-up examinations of patients. A small number...

  9. Heart rate turbulence.

    Science.gov (United States)

    Cygankiewicz, Iwona

    2013-01-01

    Heart rate turbulence (HRT) is a baroreflex-mediated biphasic reaction of heart rate in response to premature ventricular beats. Heart rate turbulence is quantified by: turbulence onset (TO) reflecting the initial acceleration of heart rate following premature beat and turbulence slope (TS) describing subsequent deceleration of heart rate. Abnormal HRT identifies patients with autonomic dysfunction or impaired baroreflex sensitivity due to variety of disorders, but also may reflect changes in autonomic nervous system induced by different therapeutic modalities such as drugs, revascularization, or cardiac resynchronization therapy. More importantly, impaired HRT has been shown to identify patients at high risk of all-cause mortality and sudden death, particularly in postinfarction and congestive heart failure patients. It should be emphasized that abnormal HRT has a well-established role in stratification of postinfarction and heart failure patients with relatively preserved left ventricular ejection fraction. The ongoing clinical trials will document whether HRT can be used to guide implantation of cardioverter-defibrillators in this subset of patients, not covered yet by ICD guidelines. This review focuses on the current state-of-the-art knowledge regarding clinical significance of HRT in detection of autonomic dysfunction and regarding the prognostic significance of this parameter in predicting all-cause mortality and sudden death. © 2013.

  10. Auditory driving of the autonomic nervous system: Listening to theta-frequency binaural beats post-exercise increases parasympathetic activation and sympathetic withdrawal.

    Science.gov (United States)

    McConnell, Patrick A; Froeliger, Brett; Garland, Eric L; Ives, Jeffrey C; Sforzo, Gary A

    2014-01-01

    Binaural beats are an auditory illusion perceived when two or more pure tones of similar frequencies are presented dichotically through stereo headphones. Although this phenomenon is thought to facilitate state changes (e.g., relaxation), few empirical studies have reported on whether binaural beats produce changes in autonomic arousal. Therefore, the present study investigated the effects of binaural beating on autonomic dynamics [heart rate variability (HRV)] during post-exercise relaxation. Subjects (n = 21; 18-29 years old) participated in a double-blind, placebo-controlled study during which binaural beats and placebo were administered over two randomized and counterbalanced sessions (within-subjects repeated-measures design). At the onset of each visit, subjects exercised for 20-min; post-exercise, subjects listened to either binaural beats ('wide-band' theta-frequency binaural beats) or placebo (carrier tones) for 20-min while relaxing alone in a quiet, low-light environment. Dependent variables consisted of high-frequency (HF, reflecting parasympathetic activity), low-frequency (LF, reflecting sympathetic and parasympathetic activity), and LF/HF normalized powers, as well as self-reported relaxation. As compared to the placebo visit, the binaural-beat visit resulted in greater self-reported relaxation, increased parasympathetic activation and increased sympathetic withdrawal. By the end of the 20-min relaxation period there were no observable differences in HRV between binaural-beat and placebo visits, although binaural-beat associated HRV significantly predicted subsequent reported relaxation. Findings suggest that listening to binaural beats may exert an acute influence on both LF and HF components of HRV and may increase subjective feelings of relaxation.

  11. Auditory driving of the autonomic nervous system: Listening to theta-frequency binaural beats post-exercise increases parasympathetic activation and sympathetic withdrawal

    Directory of Open Access Journals (Sweden)

    Patrick eMcConnell

    2014-11-01

    Full Text Available Binaural beats are an auditory illusion perceived when two or more pure tones of similar frequencies are presented dichotically through stereo headphones. Although this phenomenon is thought to facilitate state changes (e.g., relaxation, few empirical studies have reported on whether binaural beats produce changes in autonomic arousal. Therefore, the present study investigated the effects of binaural beating on autonomic dynamics (heart-rate variability (HRV during post-exercise relaxation. Subjects (n = 21; 18-29 years old participated in a double-blind, placebo-controlled study during which binaural beats and placebo were administered over two randomized and counterbalanced sessions (within-subjects repeated-measures design. At the onset of each visit, subjects exercised for 20-min; post-exercise, subjects listened to either binaural beats (‘wide-band’ theta-frequency binaural beats or placebo (carrier tone for 20-min while relaxing alone in a quiet, low-light environment. Dependent variables consisted of high frequency (HF, reflecting parasympathetic activity, low frequency (LF, reflecting sympathetic and parasympathetic activity and LF/HF normalized powers, as well as self-reported relaxation. As compared to the placebo visit, the binaural beat visit resulted in greater self-reported relaxation, as well as increased parasympathetic activation and sympathetic withdrawal. By the end of the 20-min relaxation period there were no observable differences in HRV between binaural beat and placebo visits, although binaural-beat associated HRV significantly predicted subsequent reported relaxation. Findings suggest that listening to binaural beats may exert an acute influence on both LF and HF components of HRV and may increase subjective feelings of relaxation.

  12. Association between frequency of atrial and ventricular ectopic beats and biventricular pacing percentage and outcomes in patients with cardiac resynchronization therapy.

    Science.gov (United States)

    Ruwald, Martin H; Mittal, Suneet; Ruwald, Anne-Christine; Aktas, Mehmet K; Daubert, James P; McNitt, Scott; Al-Ahmad, Amin; Jons, Christian; Kutyifa, Valentina; Steinberg, Jonathan S; Wang, Paul; Moss, Arthur J; Zareba, Wojciech

    2014-09-09

    A high percentage of biventricular pacing is required for optimal outcome in patients treated with cardiac resynchronization therapy (CRT), but the influence of ectopic beats on the success of biventricular pacing has not been well established. This study sought to determine if increased ectopic beats reduce the chance of high biventricular pacing percentage and are associated with subsequent adverse outcomes. From the MADIT-CRT (Multicenter Automatic Defibrillator Implantation Trial With Cardiac Resynchronization Therapy), 801 patients with an implanted CRT-defibrillator device with data available on biventricular pacing percentage and pre-implantation 24-h Holter recordings were included. Using logistic regression, we estimated the influence of ectopic beats on the percentage of biventricular pacing. Reverse remodeling was measured as reductions in atrial and left ventricular end-systolic volumes (LVESV) at 1 year. Cox models were used to assess the influence of ectopic beats on the outcomes of heart failure (HF) or death, ventricular tachyarrhythmias (VTAs), and death. In the pre-implantation Holter recording, ectopic beats accounted for a mean 3.2 ± 5.5% of all beats. The probability of subsequent low biventricular pacing percentage (ectopic beats and 13-fold (odds ratio: 13.42; 95% confidence interval: 7.02 to 25.66; p 1.5% ectopic beats compared with those with ectopic beats. Patients with ≥0.1% ectopic beats had significantly less reverse remodeling (percent reduction in LVESV 31 ± 15%) than patients with ectopic beats (percent reduction in LVESV 39 ± 14%; p ectopic beats (hazard ratio: 3.13 and 1.84, respectively) and for >1.5% ectopic beats (hazard ratio: 2.38 and 2.74, respectively). Relatively low frequencies of ectopic beats (≥0.1%) dramatically increase the probability of low biventricular pacing (<97%), with reduced CRT efficacy by less reverse remodeling and higher risk of HF/death and VTA. This supports pre-implantation Holter monitoring of

  13. Adult murine skeletal muscle contains cells that can differentiate into beating cardiomyocytes in vitro.

    Directory of Open Access Journals (Sweden)

    Steve O Winitsky

    2005-04-01

    Full Text Available It has long been held as scientific fact that soon after birth, cardiomyocytes cease dividing, thus explaining the limited restoration of cardiac function after a heart attack. Recent demonstrations of cardiac myocyte differentiation observed in vitro or after in vivo transplantation of adult stem cells from blood, fat, skeletal muscle, or heart have challenged this view. Analysis of these studies has been complicated by the large disparity in the magnitude of effects seen by different groups and obscured by the recently appreciated process of in vivo stem-cell fusion. We now show a novel population of nonsatellite cells in adult murine skeletal muscle that progress under standard primary cell-culture conditions to autonomously beating cardiomyocytes. Their differentiation into beating cardiomyocytes is characterized here by video microscopy, confocal-detected calcium transients, electron microscopy, immunofluorescent cardiac-specific markers, and single-cell patch recordings of cardiac action potentials. Within 2 d after tail-vein injection of these marked cells into a mouse model of acute infarction, the marked cells are visible in the heart. By 6 d they begin to differentiate without fusing to recipient cardiac cells. Three months later, the tagged cells are visible as striated heart muscle restricted to the region of the cardiac infarct.

  14. Adult Murine Skeletal Muscle Contains Cells That Can Differentiate into Beating Cardiomyocytes In Vitro

    Directory of Open Access Journals (Sweden)

    Winitsky Steve O

    2005-01-01

    Full Text Available It has long been held as scientific fact that soon after birth, cardiomyocytes cease dividing, thus explaining the limited restoration of cardiac function after a heart attack. Recent demonstrations of cardiac myocyte differentiation observed in vitro or after in vivo transplantation of adult stem cells from blood, fat, skeletal muscle, or heart have challenged this view. Analysis of these studies has been complicated by the large disparity in the magnitude of effects seen by different groups and obscured by the recently appreciated process of in vivo stem-cell fusion. We now show a novel population of nonsatellite cells in adult murine skeletal muscle that progress under standard primary cell-culture conditions to autonomously beating cardiomyocytes. Their differentiation into beating cardiomyocytes is characterized here by video microscopy, confocal-detected calcium transients, electron microscopy, immunofluorescent cardiac-specific markers, and single-cell patch recordings of cardiac action potentials. Within 2 d after tail-vein injection of these marked cells into a mouse model of acute infarction, the marked cells are visible in the heart. By 6 d they begin to differentiate without fusing to recipient cardiac cells. Three months later, the tagged cells are visible as striated heart muscle restricted to the region of the cardiac infarct.

  15. Investigating developmental cardiovascular biomechanics and the origins of congenital heart defects

    Directory of Open Access Journals (Sweden)

    William J Kowalski

    2014-10-01

    Full Text Available Innovative research on the interactions between biomechanical load and cardiovascular (CV morphogenesis by multiple investigators over the past 3 decades, including the application of bioengineering approaches, has shown that the embryonic heart adapts both structure and function in order to maintain cardiac output to the rapidly growing embryo. Acute adaptive hemodynamic mechanisms in the embryo include the redistribution of blood flow within the heart, dynamic adjustments in heart rate and developed pressure, and beat to beat variations in blood flow and vascular resistance. These biomechanically relevant events occur coincident with adaptive changes in gene expression and trigger adaptive mechanisms that include alterations in myocardial cell growth and death, regional and global changes in myocardial architecture, and alterations in central vascular morphogenesis and remodeling. These adaptive mechanisms allow the embryo to survive these biomechanical stresses (environmental, maternal and to compensate for developmental errors (genetic. Recent work from numerous laboratories shows that a subset of these adaptive mechanisms is present in every developing multicellular organism with a heart equivalent structure. This chapter will provide the reader with an overview of some of the approaches used to quantify embryonic CV functional maturation and performance, provide several illustrations of experimental interventions that explore the role of biomechanics in the regulation of CV morphogenesis including the role of computational modeling, and identify several critical areas for future investigation as available experimental models and methods expand.

  16. The Harvard Beat Assessment Test (H-BAT): a battery for assessing beat perception and production and their dissociation.

    Science.gov (United States)

    Fujii, Shinya; Schlaug, Gottfried

    2013-01-01

    Humans have the abilities to perceive, produce, and synchronize with a musical beat, yet there are widespread individual differences. To investigate these abilities and to determine if a dissociation between beat perception and production exists, we developed the Harvard Beat Assessment Test (H-BAT), a new battery that assesses beat perception and production abilities. H-BAT consists of four subtests: (1) music tapping test (MTT), (2) beat saliency test (BST), (3) beat interval test (BIT), and (4) beat finding and interval test (BFIT). MTT measures the degree of tapping synchronization with the beat of music, whereas BST, BIT, and BFIT measure perception and production thresholds via psychophysical adaptive stair-case methods. We administered the H-BAT on thirty individuals and investigated the performance distribution across these individuals in each subtest. There was a wide distribution in individual abilities to tap in synchrony with the beat of music during the MTT. The degree of synchronization consistency was negatively correlated with thresholds in the BST, BIT, and BFIT: a lower degree of synchronization was associated with higher perception and production thresholds. H-BAT can be a useful tool in determining an individual's ability to perceive and produce a beat within a single session.

  17. The Harvard Beat Assessment Test (H-BAT: A Battery for Assessing Beat Perception and Production and their Dissociation

    Directory of Open Access Journals (Sweden)

    Shinya eFujii

    2013-11-01

    Full Text Available Humans have the abilities to perceive, produce, and synchronize with a musical beat, yet there are widespread individual differences. To investigate these abilities and to determine if a dissociation between beat perception and production exists, we developed the Harvard Beat Assessment Test (H-BAT, a new battery that assesses beat perception and production abilities. H-BAT consists of four subtests: 1 music tapping test (MTT, 2 beat saliency test (BST, 3 beat interval test (BIT, and 4 beat finding and interval test (BFIT. MTT measures the degree of tapping synchronization with the beat of music, whereas BST, BIT, and BFIT measure perception and production thresholds via psychophysical adaptive stair-case methods. We administered the H-BAT on thirty individuals and investigated the performance distribution across these individuals in each subtest. There was a wide distribution in individual abilities to tap in synchrony with the beat of music during the MTT. The degree of synchronization consistency was negatively correlated with thresholds in the BST, BIT, and BFIT: a lower degree of synchronization was associated with higher perception and production thresholds. H-BAT can be a useful tool in determining an individual’s ability to perceive and produce a beat within a single session.

  18. A new Bayesian Earthquake Analysis Tool (BEAT)

    Science.gov (United States)

    Vasyura-Bathke, Hannes; Dutta, Rishabh; Jónsson, Sigurjón; Mai, Martin

    2017-04-01

    Modern earthquake source estimation studies increasingly use non-linear optimization strategies to estimate kinematic rupture parameters, often considering geodetic and seismic data jointly. However, the optimization process is complex and consists of several steps that need to be followed in the earthquake parameter estimation procedure. These include pre-describing or modeling the fault geometry, calculating the Green's Functions (often assuming a layered elastic half-space), and estimating the distributed final slip and possibly other kinematic source parameters. Recently, Bayesian inference has become popular for estimating posterior distributions of earthquake source model parameters given measured/estimated/assumed data and model uncertainties. For instance, some research groups consider uncertainties of the layered medium and propagate these to the source parameter uncertainties. Other groups make use of informative priors to reduce the model parameter space. In addition, innovative sampling algorithms have been developed that efficiently explore the often high-dimensional parameter spaces. Compared to earlier studies, these improvements have resulted in overall more robust source model parameter estimates that include uncertainties. However, the computational demands of these methods are high and estimation codes are rarely distributed along with the published results. Even if codes are made available, it is often difficult to assemble them into a single optimization framework as they are typically coded in different programing languages. Therefore, further progress and future applications of these methods/codes are hampered, while reproducibility and validation of results has become essentially impossible. In the spirit of providing open-access and modular codes to facilitate progress and reproducible research in earthquake source estimations, we undertook the effort of producing BEAT, a python package that comprises all the above-mentioned features in one

  19. Review: Beate Krais & Gunter Gebauer (2002). Habitus

    OpenAIRE

    Spetsmann-Kunkel, Martin

    2003-01-01

    Beate KRAIS' und Gunter GEBAUERs Buch führt auf eine sehr verständliche Weise in das von Pierre BOURDIEU entwickelte Konzept des Habitus ein. Habitus ist der zentrale Begriff im gesamten Werk BOURDIEUs, welcher bemüht ist, den Menschen als vergesellschaftetes Subjekt zu beschreiben. Anders als der ältere Begriff der sozialen Rolle ist der Habitus als ein generatives Prinzip zu denken, das sowohl an der (Re-) Produktion sozialer Strukturen beteiligt ist als auch diese Strukturen verinnerlicht ...

  20. Record low β beating in the LHC

    Directory of Open Access Journals (Sweden)

    R. Tomás

    2012-09-01

    Full Text Available The LHC is currently operating with a proton energy of 4 TeV and β^{*} functions at the ATLAS and CMS interaction points of 0.6 m. This is close to the design value at 7 TeV (β^{*}=0.55  m and represented a challenge for various aspects of the machine operation. In particular, a huge effort was put into the optics commissioning and an unprecedented peak β beating of around 7% was achieved in a high energy hadron collider.

  1. Beats on the Table: Beat Writing in the Chicago Review and Big Table

    Directory of Open Access Journals (Sweden)

    Jaap van der Bent

    2012-07-01

    Full Text Available Normal 0 21 false false false NL X-NONE X-NONE MicrosoftInternetExplorer4 Kleine literaire tijdschriften, zogenaamde little magazines, hebben een belangrijke rol gespeeld bij de doorbraak, in de loop van de jaren vijftig, van de Amerikaanse Beat Generation. Aangezien grotere uitgeverijen en de gevestigde tijdschriften lange tijd terugschrokken voor de zowel inhoudelijk als formeel van de norm afwijkende uitingen van de Beats, verscheen hun werk aanvankelijk vooral in kleinere tijdschriften als de twee waaraan in dit artikel aandacht wordt besteed: de Chicago Review en Big Table. Aan de hand van een beschrijving van de inhoud van deze twee tijdschriften wordt geprobeerd duidelijk te maken hoe het werk van de Beat Generation zich in deze tijdschriften gaandeweg een eigen plaats verwierf. Speciale aandacht wordt besteed aan de rol van de redacteuren Irving Rosenthal en Paul Carroll; door zijn uitgekiende strategie om voor het omstreden werk van Beat-auteur William S. Burroughs geleidelijk een steeds grotere plaats in te ruimen, bepaalde vooral Rosenthal het veranderende karakter van de Chicago Review. De veranderingen bij dat tijdschrift verliepen niet zonder slag of stoot en waren voor de eigenaar ervan, de University of Chicago, op een gegeven moment aanleiding om de Chicago Review aan censuur te onderwerpen. Ook deze censuur en de reactie erop, de oprichting van Big Table, worden in het artikel belicht.

  2. Spoken Word Recognition Enhancement Due to Preceding Synchronized Beats Compared to Unsynchronized or Unrhythmic Beats

    Directory of Open Access Journals (Sweden)

    Christos Sidiras

    2017-07-01

    Full Text Available The relation between rhythm and language has been investigated over the last decades, with evidence that these share overlapping perceptual mechanisms emerging from several different strands of research. The dynamic Attention Theory posits that neural entrainment to musical rhythm results in synchronized oscillations in attention, enhancing perception of other events occurring at the same rate. In this study, this prediction was tested in 10 year-old children by means of a psychoacoustic speech recognition in babble paradigm. It was hypothesized that rhythm effects evoked via a short isochronous sequence of beats would provide optimal word recognition in babble when beats and word are in sync. We compared speech recognition in babble performance in the presence of isochronous and in sync vs. non-isochronous or out of sync sequence of beats. Results showed that (a word recognition was the best when rhythm and word were in sync, and (b the effect was not uniform across syllables and gender of subjects. Our results suggest that pure tone beats affect speech recognition at early levels of sensory or phonemic processing.

  3. Motor responses to a steady beat.

    Science.gov (United States)

    Schaefer, Rebecca S; Overy, Katie

    2015-03-01

    It is increasingly well established that music containing an isochronous pulse elicits motor responses at the levels of both brain and behavior. Such motor responses are often used in pedagogical and clinical practice to induce movement, particularly where motor functions are impaired. However, the complex nature of such apparently universal human responses has, arguably, not received adequate research attention to date. In particular, it should be noted that many adults, including those with disabilities, find it somewhat difficult to synchronize their movements with a beat with perfect accuracy; indeed, perfecting the skill of being musically "in time" can take years of training during childhood. Further research is needed on the nature of both the specificity and range of motor responses that can arise from the perception of a steady auditory pulse, with different populations, musical stimuli, conditions, and required levels of accuracy in order to better understand and capture the potential value of the musical beat as a pedagogical and therapeutic tool. © 2015 New York Academy of Sciences.

  4. Nonlinear amplitude dynamics in flagellar beating

    Science.gov (United States)

    Oriola, David; Gadêlha, Hermes; Casademunt, Jaume

    2017-03-01

    The physical basis of flagellar and ciliary beating is a major problem in biology which is still far from completely understood. The fundamental cytoskeleton structure of cilia and flagella is the axoneme, a cylindrical array of microtubule doublets connected by passive cross-linkers and dynein motor proteins. The complex interplay of these elements leads to the generation of self-organized bending waves. Although many mathematical models have been proposed to understand this process, few attempts have been made to assess the role of dyneins on the nonlinear nature of the axoneme. Here, we investigate the nonlinear dynamics of flagella by considering an axonemal sliding control mechanism for dynein activity. This approach unveils the nonlinear selection of the oscillation amplitudes, which are typically either missed or prescribed in mathematical models. The explicit set of nonlinear equations are derived and solved numerically. Our analysis reveals the spatio-temporal dynamics of dynein populations and flagellum shape for different regimes of motor activity, medium viscosity and flagellum elasticity. Unstable modes saturate via the coupling of dynein kinetics and flagellum shape without the need of invoking a nonlinear axonemal response. Hence, our work reveals a novel mechanism for the saturation of unstable modes in axonemal beating.

  5. Preliminary Study of Fiber Optic Multi-Cardiac-Marker Biosensing System for Rapid Coronary Heart Disease Diagnosis and Prognosis

    Science.gov (United States)

    Tang, Liang; Kang, Kyung A.

    A fiber-optic biosensing system for the simultaneous quantification of four cardiac markers is currently under development, in our research group, for rapid coronary disease diagnosis and prognosis. As an initial effort, four individual BNP, cTnI, MG, and CRP sensors were developed. The sensors showed excellent performance in quantifying these cardiac markers in their clinically significant ranges within 15 minutes, at a S/N ratio of 25-50. The cross-reactivity of the four sensors was also found to be negligible. A mixture of four AF647-2o Mabs has shown only a slight interference to the four sensors, indicating that the mixture can be applied through a multi-sensing unit for simultaneous detection with an easier operation.

  6. Rapidly detecting disorder in rhythmic biological signals: a spectral entropy measure to identify cardiac arrhythmias

    CERN Document Server

    Staniczenko, Phillip P A; Jones, Nick S

    2008-01-01

    We consider the use of a running measure of power spectrum disorder to distinguish between the normal sinus rhythm of the heart and two forms of cardiac arrhythmia: atrial fibrillation and atrial flutter. This is motivated by characteristic differences in the spectra of beats during the three rhythms. We plot patient data derived from 10-beat windows on a `disorder map' and identify rhythm-defining ranges in the level and variance of spectral entropy values. Employing the spectral entropy within an automatic arrhythmia detection algorithm enables the classification of periods of atrial fibrillation from the time series of patients' beats. When the algorithm is set to identify abnormal rhythms within 6s it agrees with 85.7% of the annotations of professional rhythm assessors; for a response time of 30s this becomes 89.5%, and with 60s it is 90.3%. The algorithm provides a rapid way to detect atrial fibrillation, demonstrating usable response times as low as six seconds. Measures of disorder in the frequency do...

  7. Predictive Value of Beat-to-Beat QT Variability Index across the Continuum of Left Ventricular Dysfunction: Competing Risks of Non-cardiac or Cardiovascular Death, and Sudden or Non-Sudden Cardiac Death

    Science.gov (United States)

    Tereshchenko, Larisa G.; Cygankiewicz, Iwona; McNitt, Scott; Vazquez, Rafael; Bayes-Genis, Antoni; Han, Lichy; Sur, Sanjoli; Couderc, Jean-Philippe; Berger, Ronald D.; de Luna, Antoni Bayes; Zareba, Wojciech

    2012-01-01

    Background The goal of this study was to determine the predictive value of beat-to-beat QT variability in heart failure (HF) patients across the continuum of left ventricular dysfunction. Methods and Results Beat-to-beat QT variability index (QTVI), heart rate variance (LogHRV), normalized QT variance (QTVN), and coherence between heart rate variability and QT variability have been measured at rest during sinus rhythm in 533 participants of the Muerte Subita en Insuficiencia Cardiaca (MUSIC) HF study (mean age 63.1±11.7; males 70.6%; LVEF >35% in 254 [48%]) and in 181 healthy participants from the Intercity Digital Electrocardiogram Alliance (IDEAL) database. During a median of 3.7 years of follow-up, 116 patients died, 52 from sudden cardiac death (SCD). In multivariate competing risk analyses, the highest QTVI quartile was associated with cardiovascular death [hazard ratio (HR) 1.67(95%CI 1.14-2.47), P=0.009] and in particular with non-sudden cardiac death [HR 2.91(1.69-5.01), P<0.001]. Elevated QTVI separated 97.5% of healthy individuals from subjects at risk for cardiovascular [HR 1.57(1.04-2.35), P=0.031], and non-sudden cardiac death in multivariate competing risk model [HR 2.58(1.13-3.78), P=0.001]. No interaction between QTVI and LVEF was found. QTVI predicted neither non-cardiac death (P=0.546) nor SCD (P=0.945). Decreased heart rate variability (HRV) rather than increased QT variability was the reason for increased QTVI in this study. Conclusions Increased QTVI due to depressed HRV predicts cardiovascular mortality and non-sudden cardiac death, but neither SCD nor excracardiac mortality in HF across the continuum of left ventricular dysfunction. Abnormally augmented QTVI separates 97.5% of healthy individuals from HF patients at risk. PMID:22730411

  8. When heart goes "BOOM" to fast. Heart rate greater than 80 as mortality predictor in acute myocardial infarction.

    Science.gov (United States)

    Davidovic, Goran; Iric-Cupic, Violeta; Milanov, Srdjan; Dimitijevic, Aleksandra; Petrovic-Janicijevic, Mirjana

    2013-01-01

    Many prospective studies established association between high heart rate and increased cardiovascular morbidity and mortality, independently of other risk factors. Heart rate over 80 beats per minute more often leads to atherosclerotic plaque disruption, the main step in developing acute coronary syndrome. Purpose was to investigate the incidence of higher heart rate levels in patients with anterior wall acute myocardial infarction with ST-segment elevation and the influence of heart rate on mortality. Research included 140 patients with anterior wall acute myocardial infarction with ST-segment elevation treated in Coronary Unit, Clinical Center Kragujevac in the period from January 2001-June 2006. Heart rate was calculated as the mean value of baseline and heart rate in the first 30 minutes after admission. Other risk factors were also followed to determine their connection with elevated heart rate. Results showed that the majority of patients survived (over 70%). In a total number of patients, more than 75% had a heart rate levels greater than 80 beats per minute. There was a significant difference in heart rate on addmision between survivors and patients who died, with a greater levels in patients with fatal outcome. Both, univariate and multivariate regression analysis singled out heart rate greater than 80 beats per minute as independent mortality predictor in these patients. Heart rate greater than 80 beats per minute is a major, independent risk factor for morbidity and important predictor of mortality in patients with acute myocardial infarction.

  9. Nonlinear amplitude dynamics in flagellar beating

    CERN Document Server

    Oriola, David; Casademunt, Jaume

    2016-01-01

    The physical basis of flagellar and ciliary beating is a major problem in biology which is still far from completely understood. The fundamental cytoskeleton structure of cilia and flagella is the axoneme, a cylindrical array of microtubule doublets connected by passive crosslinkers and dynein motor proteins. The complex interplay of these elements leads to the generation of self-organized bending waves. Although many mathematical models have been proposed to understand this process, few attempts have been made to assess the role of dyneins on the nonlinear nature of the axoneme. Here, we investigate the nonlinear dynamics of flagella by considering an axonemal sliding control mechanism for dynein activity. This approach unveils the nonlinear selection of the oscillation amplitudes, which are typically either missed or prescribed in mathematical models. The explicit set of nonlinear equations are derived and solved numerically. Our analysis reveals the spatiotemporal dynamics of dynein populations and flagell...

  10. Beating Social Democracy on Its Own Turf

    DEFF Research Database (Denmark)

    Arndt, Christoph

    2014-01-01

    Recent elections yielded sweeping majorities for the centre-right in Scandinavia with a decade of pure centre-right majorities in Denmark and the longest sitting centre-right coalition in Sweden for decades. This is a blind spot in the issue voting literature, which would not expect centre......-right parties to flourish in contexts where welfare issues have a natural salience as in the case of universal welfare states. In contrast, Scandinavian universal welfare states ought to benefit social democracy when it comes to issue voting on welfare issues. It is argued in this article that centre......-right parties can beat social democrats by credibly converging to its social democratic opponent on issues of universal welfare. Issue ownership voting to the benefit of centre-right parties will then be strongest among voters perceiving the centre-right to have converged to social democracy and perceiving...

  11. What makes a rhythm complex? The influence of musical training and accent type on beat perception

    Science.gov (United States)

    Burgoyne, J. Ashley; Odijk, Daan; Honing, Henkjan; Grahn, Jessica A.

    2018-01-01

    Perception of a regular beat in music is inferred from different types of accents. For example, increases in loudness cause intensity accents, and the grouping of time intervals in a rhythm creates temporal accents. Accents are expected to occur on the beat: when accents are “missing” on the beat, the beat is more difficult to find. However, it is unclear whether accents occurring off the beat alter beat perception similarly to missing accents on the beat. Moreover, no one has examined whether intensity accents influence beat perception more or less strongly than temporal accents, nor how musical expertise affects sensitivity to each type of accent. In two experiments, we obtained ratings of difficulty in finding the beat in rhythms with either temporal or intensity accents, and which varied in the number of accents on the beat as well as the number of accents off the beat. In both experiments, the occurrence of accents on the beat facilitated beat detection more in musical experts than in musical novices. In addition, the number of accents on the beat affected beat finding more in rhythms with temporal accents than in rhythms with intensity accents. The effect of accents off the beat was much weaker than the effect of accents on the beat and appeared to depend on musical expertise, as well as on the number of accents on the beat: when many accents on the beat are missing, beat perception is quite difficult, and adding accents off the beat may not reduce beat perception further. Overall, the different types of accents were processed qualitatively differently, depending on musical expertise. Therefore, these findings indicate the importance of designing ecologically valid stimuli when testing beat perception in musical novices, who may need different types of accent information than musical experts to be able to find a beat. Furthermore, our findings stress the importance of carefully designing rhythms for social and clinical applications of beat perception, as

  12. Gimme the beat: assessment of low frequency beat noise for drilling rig

    Energy Technology Data Exchange (ETDEWEB)

    Bilawchuk, Steven; Froment, Patrick [aci Acoustical Consultants Inc. (Canada)], email: stevenb@aciacoustical.com, email: patrickf@aciacoustical.com

    2011-07-01

    The concern of an Alberta resident over the noise level from a drilling rig led to a low frequency noise impact assessment being done by an acoustic consulting firm. This paper describes the investigation that was conducted to determine the low frequency noise source, evaluate its sound emission levels and spectra, and propose mitigation options. Noise measurements were made over several days, with a sound level meter and additionally, a weather monitoring station was also used. Analysis showed low frequency tonal noise at the residential location, resulting in an overall sound level exceeding the permissible sound level imposed by the Alberta noise regulating bodies. Moreover, a beat phenomenon was observed, and after detailed investigation of possible sources, it was established that shale shakers were responsible for the low frequency noise and the beat phenomenon, a fact verified by beat theory. Due to the temporary nature of the drilling rig's operation, no thorough mitigation options could be proposed but a simple stop gap solution for the shale shakers allowed the reduction of low frequency tonal noise.

  13. HEART RATE DURING SLEEP: IMPLICATIONS FOR MONITORING TRAINING STATUS

    Directory of Open Access Journals (Sweden)

    Miriam R. Waldeck

    2003-12-01

    Full Text Available Resting heart rate has sometimes been used as a marker of training status. It is reasonable to assume that the relationship between heart rate and training status should be more evident during sleep when extraneous factors that may influence heart rate are reduced. Therefore the aim of the study was to assess the repeatability of monitoring heart rate during sleep when training status remained unchanged, to determine if this measurement had sufficient precision to be used as a marker of training status. The heart rate of ten female subjects was monitored for 24 hours on three occasions over three weeks whilst training status remained unchanged. Average, minimum and maximum heart rate during sleep was calculated. The average heart rate of the group during sleep was similar on each of the three tests (65 ± 9, 63 ± 6 and 67 ± 7 beats·min-1 respectively. The range in minimum heart rate variation during sleep for all subjects over the three testing sessions was from 0 to 10 beats·min-1 (mean = 5 ± 3 beats·min-1 and for maximum heart rate variation was 2 to 31 beats·min-1 (mean = 13 ± 9 beats·min-1. In summary it was found that on an individual basis the minimum heart rate during sleep varied by about 8 beats·min-1. This amount of intrinsic day-to-day variation needs to be considered when changes in heart rate that may occur with changes in training status are interpreted

  14. Heart rate during sleep: implications for monitoring training status.

    Science.gov (United States)

    Waldeck, Miriam R; Lambert, Michael I

    2003-12-01

    Resting heart rate has sometimes been used as a marker of training status. It is reasonable to assume that the relationship between heart rate and training status should be more evident during sleep when extraneous factors that may influence heart rate are reduced. Therefore the aim of the study was to assess the repeatability of monitoring heart rate during sleep when training status remained unchanged, to determine if this measurement had sufficient precision to be used as a marker of training status. The heart rate of ten female subjects was monitored for 24 hours on three occasions over three weeks whilst training status remained unchanged. Average, minimum and maximum heart rate during sleep was calculated. The average heart rate of the group during sleep was similar on each of the three tests (65 ± 9, 63 ± 6 and 67 ± 7 beats·min(-1) respectively). The range in minimum heart rate variation during sleep for all subjects over the three testing sessions was from 0 to 10 beats·min(-1) (mean = 5 ± 3 beats·min(-1)) and for maximum heart rate variation was 2 to 31 beats·min(-1) (mean = 13 ± 9 beats·min(-1)). In summary it was found that on an individual basis the minimum heart rate during sleep varied by about 8 beats·min(-1). This amount of intrinsic day-to-day variation needs to be considered when changes in heart rate that may occur with changes in training status are interpreted.

  15. Computerized image processing in the Reginald Denny beating trial

    Science.gov (United States)

    Morrison, Lawrence C.

    1997-02-01

    New image processing techniques may have significant benefits to law enforcement officials but need to be legally admissible in court. Courts have different tests for determining the admissibility of new scientific procedures, requiring their reliability to be established by expert testimony. The first test developed was whether there has been general acceptance of the new procedure within the scientific community. In 1993 the U.S. Supreme Court loosened the requirements for admissibility of new scientific techniques, although the California Supreme Court later retained the general acceptance test. What the proper standard is for admission of such evidence is important to both the technical community and to the legal community because of the conflict between benefits of rapidly developing technology, and the dangers of 'junk science.' The Reginald Denny beating case from the 1992 Los Angeles riots proved the value of computerized image processing in identifying persons committing crimes on videotape. The segmentation process was used to establish the presence of a tattoo on one defendant, which was key in his identification. Following the defendant's conviction, the California Court of Appeal approved the use of the evidence involving the segmentation process. This published opinion may be cited as legal precedent.

  16. The effect of music with and without binaural beat audio on operative anxiety in patients undergoing cataract surgery: a randomized controlled trial.

    Science.gov (United States)

    Wiwatwongwana, D; Vichitvejpaisal, P; Thaikruea, L; Klaphajone, J; Tantong, A; Wiwatwongwana, A

    2016-11-01

    PurposeTo investigate the anxiolytic effects of binaural beat embedded audio in patients undergoing cataract surgery under local anesthesia.MethodsThis prospective RCT included 141 patients undergoing cataract surgery under local anesthesia. The patients were randomized into three groups; the Binaural beat music group (BB), the plain music intervention group (MI), and a control group (ear phones with no music). Blood pressure (BP) and heart rate were measured on admission, at the beginning of and 20 min after the start of the operation. Peri-operative anxiety level was assessed using the State-Trait Anxiety Inventory questionnaire (STAI).ResultsThe BB and MI groups comprised 44 patients each and the control group 47. Patients in the MI group and BB group showed significant reduction of STAI state scores after music intervention compared with the control group (Pbinaural beat, was proven to decrease anxiety level and lower systolic BP. Patients who received binaural beat audio showed additional decrease in heart rate. Binaural beat embedded musical intervention may have benefit over musical intervention alone in decreasing operative anxiety.

  17. Tempo and beat analysis of acoustic musical signals.

    Science.gov (United States)

    Scheirer, E D

    1998-01-01

    A method is presented for using a small number of bandpass filters and banks of parallel comb filters to analyze the tempo of, and extract the beat from, musical signals of arbitrary polyphonic complexity and containing arbitrary timbres. This analysis is performed causally, and can be used predictively to guess when beats will occur in the future. Results in a short validation experiment demonstrate that the performance of the algorithm is similar to the performance of human listeners in a variety of musical situations. Aspects of the algorithm are discussed in relation to previous high-level cognitive models of beat tracking.

  18. Beliefs about wife beating: an exploratory study with Lebanese students.

    Science.gov (United States)

    Obeid, Nadine; Chang, Doris F; Ginges, Jeremy

    2010-06-01

    In recent years, there has been a growing interest in understanding the sociocultural contexts and risk factors for domestic violence in the Arab world. This study provides an analysis of the religious, legal, and familial contexts of domestic violence in Lebanon and assesses contemporary attitudes toward women and wife beating in a sample of 206 Lebanese university students. Gender, patriarchal attitudes, religion, childhood experiences with family violence, and mother's employment status were investigated as predictors of attitudes toward wife beating. Consistent with feminist theories of wife abuse, gender and attitudes toward women's roles emerged as the strongest predictors of beliefs about wife beating.

  19. Generic flow profiles induced by a beating cilium.

    Science.gov (United States)

    Vilfan, A

    2012-08-01

    We describe a multipole expansion for the low-Reynolds-number fluid flows generated by a localized source embedded in a plane with a no-slip boundary condition. It contains 3 independent terms that fall quadratically with the distance and 6 terms that fall with the third power. Within this framework we discuss the flows induced by a beating cilium described in different ways: a small particle circling on an elliptical trajectory, a thin rod and a general ciliary beating pattern. We identify the flow modes present based on the symmetry properties of the ciliary beat.

  20. On-chip constructive cell-network study (I): contribution of cardiac fibroblasts to cardiomyocyte beating synchronization and community effect.

    Science.gov (United States)

    Kaneko, Tomoyuki; Nomura, Fumimasa; Yasuda, Kenji

    2011-05-23

    To clarify the role of cardiac fibroblasts in beating synchronization, we have made simple lined-up cardiomyocyte-fibroblast network model in an on-chip single-cell-based cultivation system. The synchronization phenomenon of two cardiomyocyte networks connected by fibroblasts showed (1) propagation velocity of electrophysiological signals decreased a magnitude depending on the increasing number of fibroblasts, not the lengths of fibroblasts; (2) fluctuation of interbeat intervals of the synchronized two cardiomyocyte network connected by fibroblasts did not always decreased, and was opposite from homogeneous cardiomyocyte networks; and (3) the synchronized cardiomyocytes connected by fibroblasts sometimes loses their synchronized condition and recovered to synchronized condition, in which the length of asynchronized period was shorter less than 30 beats and was independent to their cultivation time, whereas the length of synchronized period increased according to cultivation time. The results indicated that fibroblasts can connect cardiomyocytes electrically but do not significantly enhance and contribute to beating interval stability and synchronization. This might also mean that an increase in the number of fibroblasts in heart tissue reduces the cardiomyocyte 'community effect', which enhances synchronization and stability of their beating rhythms.

  1. "'Jackin’ for Beats'": DJing for Citation Critique

    Directory of Open Access Journals (Sweden)

    Todd Craig

    2013-10-01

    Full Text Available A challenge in teaching English composition is helping students envision plagiarism as “borrowing” – showing love to author(s and/or text(s that further their argument(s, versus “stealing” – biting someone’s style and words. Alastair Pennycook (1996 and Sarah Wakefield (2006 have contributed pieces to the elaborate plagiarism/citation puzzle, while Houston Baker situated the hip-hop DJ in seminal text Black Studies, Rap and the Academy (1993. Merging these moments introduces critical questions: Did Diddy invent “the remix” or become the illest beat-biter ever? How did DJ/Producers Pete Rock and Large Professor pay homage to previous musical genres to further hip-hop remix production without just taking 4-8 bar samples, copying sources and claiming unethical ownership? And how can this discussion provide students a window into citation conversations? This article will remix these “texts” to introduce the idea of DJ Rhetoric to discuss plagiarism. Through the lens of the hip-hop DJ in writing classrooms, one can foster an appreciation of the difference between “love and theft” in student citation. This article will couple examples from hip-hop music/culture while simultaneously remixing interviews from various hip-hop DJ/producers to help answer these difficult questions.

  2. Selective particle capture by asynchronously beating cilia

    Science.gov (United States)

    Ding, Yang; Kanso, Eva

    2015-12-01

    Selective particle filtration is fundamental in many engineering and biological systems. For example, many aquatic microorganisms use filter feeding to capture food particles from the surrounding fluid, using motile cilia. One of the capture strategies is to use the same cilia to generate feeding currents and to intercept particles when the particles are on the downstream side of the cilia. Here, we develop a 3D computational model of ciliary bands interacting with flow suspended particles and calculate particle trajectories for a range of particle sizes. Consistent with experimental observations, we find optimal particle sizes that maximize capture rate. The optimal size depends nonlinearly on cilia spacing and cilia coordination, synchronous vs. asynchronous. These parameters affect the cilia-generated flow field, which in turn affects particle trajectories. The low capture rate of smaller particles is due to the particles' inability to cross the flow streamlines of neighboring cilia. Meanwhile, large particles have difficulty entering the sub-ciliary region once advected downstream, also resulting in low capture rates. The optimal range of particle sizes is enhanced when cilia beat asynchronously. These findings have potentially important implications on the design and use of biomimetic cilia in processes such as particle sorting in microfluidic devices.

  3. The heartbrake of social rejection: heart rate deceleration in response to unexpected peer rejection

    NARCIS (Netherlands)

    Gunther Moor, B.; Crone, E.A.; van der Molen, M.W.

    2010-01-01

    Social relationships are vitally important in human life. Social rejection in particular has been conceptualized as a potent social cue resulting in feelings of hurt. Our study investigated the psychophysiological manifestation of hurt feelings by examining the beat-by-beat heart rate response

  4. Beat-to-beat P-wave morphology as a predictor of paroxysmal atrial fibrillation.

    Science.gov (United States)

    Filos, Dimitrios; Chouvarda, Ioanna; Tachmatzidis, Dimitris; Vassilikos, Vassilios; Maglaveras, Nicos

    2017-11-01

    Atrial Fibrillation (AF) is the most common cardiac arrhythmia. The initiation and the perpetuation of AF is linked with phenomena of atrial remodeling, referring to the modification of the electrical and structural characteristics of the atrium. P-wave morphology analysis can reveal information regarding the propagation of the electrical activity on the atrial substrate. The purpose of this study is to investigate patterns on the P-wave morphology that may occur in patients with Paroxysmal AF (PAF) and which can be the basis for distinguishing between PAF and healthy subjects. Vectorcardiographic signals in the three orthogonal axes (X, Y and Z), of 3-5 min duration, were analyzed during SR. In total 29 PAF patients and 34 healthy volunteers were included in the analysis. These data were divided into two distinct datasets, one for the training and one for the testing of the proposed approach. The method is based on the identification of the dominant and the secondary P-wave morphology by combining adaptive k-means clustering of morphologies and a beat-to-beat cross correlation technique. The P-waves of the dominant morphology were further analyzed using wavelet transform whereas time domain characteristics were also extracted. Following a feature selection step, a SVM classifier was trained, for the discrimination of the PAF patients from the healthy subjects, while its accuracy was tested using the independent testing dataset. In the cohort study, in both groups, the majority of the P-waves matched a main and a secondary morphology, while other morphologies were also present. The percentage of P-waves which simultaneously matched the main morphology in all three leads was lower in PAF patients (90.4 ± 7.8%) than in healthy subjects (95.5 ± 3.4%, p= 0.019). Three optimal scale bands were found and wavelet parameters were extracted which presented statistically significant differences between the two groups. Classification between the two groups was

  5. Drug Beats Steroids for Controlling Blood Vessel Inflammation in Study

    Science.gov (United States)

    ... html Drug Beats Steroids for Controlling Blood Vessel Inflammation in Study With tocilizumab's approval, there's an alternative ... treating the most common form of blood vessel inflammation known as giant cell arteritis, a new study ...

  6. Modulation of attosecond beating in resonant two-photon ionization

    CERN Document Server

    Galán, Álvaro J; Martín, Fernando

    2014-01-01

    We present a theoretical study of the photoelectron attosecond beating at the basis of RABBIT (Reconstruction of Attosecond Beating By Interference of Two-photon transitions) in the presence of autoionizing states. We show that, as a harmonic traverses a resonance, its sidebands exhibit a peaked phase shift as well as a modulation of the beating frequency itself. Furthermore, the beating between two resonant paths persists even when the pump and the probe pulses do not overlap, thus providing a sensitive non-holographic interferometric means to reconstruct coherent metastable wave packets. We characterize these phenomena quantitatively with a general finite-pulse analytical model that accounts for the effect of both intermediate and final resonances on two-photon processes, at a negligible computational cost. The model predictions are in excellent agreement with those of accurate ab initio calculations for the helium atom in the region of the N=2 doubly excited states.

  7. Heritability of wing-beat frequency in Anopheles quadrimaculatus.

    Science.gov (United States)

    Robertson, Shawn P; Caprio, Michael A; Faver, Marla K

    2002-12-01

    The repeatability of male wing-beat frequency measurements of Anopheles quadrimaculatus was determined by using mosquitoes allowed free flight in a confined space. Heritability of the wing-beat frequency trait was estimated for a laboratory and a wild-strain population of An. quadrimaculatus by using free-flight measurement with a parent-offspring regression of offspring on dams. Repeatability was 0.75 for free flight. Wing-beat frequency rose for the 1st day after adult emergence and then became steady. Female heritability of wing-beat frequency was 21.6% for colony and 24.0% for wild-strain mosquitoes. Male heritability was 57.2% for colony and 53.7% for wild-strain mosquitoes. Male heritability was significantly different from 0 when probabilities were combined across both populations.

  8. When heart goes “BOOM” to fast. Heart rate greater than 80 as mortality predictor in acute myocardial infarction

    OpenAIRE

    Davidovic, Goran; Iric-Cupic, Violeta; Milanov, Srdjan; Dimitijevic, Aleksandra; Petrovic-Janicijevic, Mirjana

    2013-01-01

    Many prospective studies established association between high heart rate and increased cardiovascular morbidity and mortality, independently of other risk factors. Heart rate over 80 beats per minute more often leads to atherosclerotic plaque disruption, the main step in developing acute coronary syndrome. Purpose was to investigate the incidence of higher heart rate levels in patients with anterior wall acute myocardial infarction with ST-segment elevation and the influence of heart rate on ...

  9. A FABP-ulous 'rule out' strategy? Heart fatty acid binding protein and troponin for rapid exclusion of acute myocardial infarction.

    Science.gov (United States)

    Body, Richard; McDowell, Garry; Carley, Simon; Wibberley, Christopher; Ferguson, Jamie; Mackway-Jones, Kevin

    2011-08-01

    Many Emergency Departments (EDs) utilise 'triple marker' testing with CK-MB, myoglobin and troponin I (cTnI) to exclude acute myocardial infarction (AMI) within hours of presentation. We evaluated the ability of 8 biomarkers to rapidly exclude AMI at the point of presentation and investigated whether 'triple marker' testing represents the optimal multimarker strategy. We recruited patients who presented to the ED with suspected cardiac chest pain occurring within 24 h. Blood was drawn at the time of presentation. Diagnostic value was assessed by calculating the area under the ROC curve (AUC) and a multivariate model was constructed by logistic regression. The primary outcome was a diagnosis of AMI, established by ≥12-h troponin testing in all patients. 705 included patients underwent venepuncture a median of 3.5 h after symptom onset. Heart fatty acid binding protein (H-FABP) had an AUC of 0.86 (95% CI 0.82-0.90), which was significantly higher than any other biomarker including cTnI. While no single biomarker could enable exclusion of AMI, multivariate analysis identified cTnI and H-FABP as the optimal biomarker combination. Combined with clinical risk stratification, this strategy had a sensitivity of 96.9%, specificity of 54.7%, PPV 32.4% and NPV 98.8%. We have derived an algorithm that would enable AMI to be immediately excluded in 315 (44.7%) patients at the cost of missing 6 AMIs per 1000 patients treated. While the risk is likely to be unacceptable for clinical implementation, we have highlighted an area for future development using serial testing and increasingly sensitive assays. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

  10. Correlation between regular mouthing movements and heart rate patterns during non-rapid eye movement periods in normal human fetuses between 32 and 40 weeks of gestation.

    Science.gov (United States)

    Otera, Yuka; Morokuma, Seiichi; Fukushima, Kotaro; Wake, Norio; Kato, Kiyoko

    2013-06-01

    Regular mouthing movements (RMMs) are observed during fetal non-rapid eye movement (NREM) periods. To determine the correlation between RMM and fetal heart rate (FHR) patterns during NREM periods. Fetal eye and mouth movements and FHR patterns were observed and recorded. 50 normal singleton pregnancies between 32 and 40 weeks of gestation. Changes in the power spectrum ratio of 3-minute blocks of RMM clusters, FHR with RMM clusters (HR+), and FHR without RMM clusters (HR-) were calculated at a frequency band of 0.02 Hz among 3 gestational age groups: group 1, 32-34 weeks gestation; group 2, 35-37 weeks gestation; group 3, 38-40 weeks gestation. We calculated the percentage of cases showing dominant peak ratios of RMM and HR+ in the same frequency band, the maximum correlation coefficient, and its lag time. In group 3, the dominant peaks of both RM and HR+ were present at the same frequency band, 0.06-0.08 Hz; this was not seen in the other groups' relative power spectral patterns. The percentage of cases showing dominant peaks of RMM and HR+ in the same frequency band increased with advancing gestational age. The maximum correlation coefficient in groups 1 (0.28 ± 0.11) and 3 (0.45 ± 0.14) differed significantly (p<0.05). The correlation between RMM and FHR patterns became stronger, and their rhythmicity was similar, from 38 to 40 gestational weeks, suggesting that a common center starts to govern both patterns at approximately 38 weeks gestation. Copyright © 2012 Elsevier Ltd. All rights reserved.

  11. Electrocardiogram: his bundle potentials can be recorded noninvasively beat by beat on surface electrocardiogram.

    Science.gov (United States)

    Wang, Gaopin; Liu, Renguang; Chang, Qinghua; Xu, Zhaolong; Zhang, Yingjie; Pan, Dianzhu

    2017-03-15

    The micro waveform of His bundle potential can't be recorded beat-to-beat on surface electrocardiogram yet. We have found that the micro-wavelets before QRS complex may be related to atrioventricular conduction system potentials. This study is to explore the possibility of His bundle potential can be noninvasively recorded on surface electrocardiogram. We randomized 65 patients undergoing radiofrequency catheter ablation of paroxysmal superventricular tachycardia (exclude overt Wolff-Parkinson-White syndrome) to receive "conventional electrocardiogram" and "new electrocardiogram" before the procedure. His bundle electrogram was collected during the procedure. Comparative analysis of PA s (PA interval recorded on surface electrocardiogram), AH s (AH interval recorded on surface electrocardiogram) and HV s (HV interval recorded on surface electrocardiogram) interval recorded on surface "new electrocardiogram" and PA, AH, HV interval recorded on His bundle electrogram was investigated. There was no difference (P > 0.05) between groups in HV s interval (49.63 ± 6.19 ms) and HV interval (49.35 ± 6.49 ms). Results of correlational analysis found that HV S interval was significantly positively associated with HV interval (r = 0.929; P electrocardiogram. Noninvasive His bundle potential tracing might represent a new method for locating the site of atrioventricular block and identifying the origin of a wide QRS complex.

  12. Beat-to-beat blood pressure variability and patent ductus arteriosus in ventilated, premature infants.

    Science.gov (United States)

    Beuchée, Alain; Pladys, Patrick; Senhadji, Lotfi; Bétrémieux, Pierre; Carré, François

    2003-05-01

    The aim of the present study was to test the hypothesis that a relationship exists between respiratory-induced blood pressure variability (BPV) and transductal shunting in premature infants with respiratory distress. Ten premature infants (27-32 weeks gestation) with respiratory distress ventilated in the synchronised, positive-pressure mode were examined. The interrelations between blood pressure and transthoracic impedance were described using time and frequency domain analysis. Haemodynamic effects of left-to-right transductal shunting were assessed using Doppler echocardiography (ratio of diastolic flow to systolic flow in the subdiaphragmatic aorta). The dependence of blood pressure fluctuations on the respiratory cycle was seen consistently in both time-domain and cross-spectral analysis. The amplitude of these fluctuations varied between infants. In the time domain, the beat-to-beat pressure difference was 0.69-4.1 mmHg for diastolic and 0.99-5.24 mmHg for systolic blood pressure. There was a positive linear relationship between the respiratory-related BPV indicators and the extent of left-to-right transductal shunting ( r=0.86 for diastolic and 0.80 for systolic pressure, P<0.01). Respiratory-related BPV was not correlated to the indicators of left ventricle preload. It is concluded that respiratory related BPV involves both diastolic and systolic blood pressure and is correlated to the magnitude of left-to-right transductal shunting in the population studied.

  13. Using a Phototransduction System to Monitor the Isolated Frog Heart

    Science.gov (United States)

    Stephens, Philip J.

    2015-01-01

    A simple and inexpensive method of monitoring the movement of an isolated frog heart provides comparable results to those obtained with a force transducer. A commercially available photoresistor is integrated into a Wheatstone bridge circuit, and the output signal is interfaced directly with a recording device. An excised, beating frog heart is…

  14. Beat-to-beat tracking of systolic blood pressure using noninvasive pulse transit time during anesthesia induction in hypertensive patients.

    Science.gov (United States)

    Kim, Sung-Hoon; Song, Jun-Gol; Park, Ji-Hyun; Kim, Jung-Won; Park, Yong-Seok; Hwang, Gyu-Sam

    2013-01-01

    Pulse transit time (PTT) has been reported to show good agreement with arterial blood pressure (BP) in awake humans. We evaluated whether noninvasive beat-to-beat PTT accurately correlated with invasively measured continuous arterial BP during anesthesia induction in hypertensive patients. Twenty-three hypertensive patients who were scheduled for kidney transplant were enrolled. Radial arterial BP, electrocardiogram, and finger pulse oximetric plethysmography were simultaneously recorded. PTT was measured as the time interval from the R-wave peak on the electrocardiogram to the maximal upslope of the photoplethysmogram. Relationships between beat-to-beat PTT and BP were evaluated by correlation and receiver operating characteristic (ROC) curve analysis. During anesthesia induction, changes in PTT were directly proportional to changes in BP: when BP decreased, PTT lengthened, and vice versa. The inverse of PTT demonstrated significantly better correlation with systolic BP than with mean BP (r = 0.81 ± 0.11 vs r = 0.72 ± 0.17; P < 0.001) or diastolic BP (r = 0.81 ± 0.11 vs r = 0.52 ± 0.24; P < 0.001). The inverse of PTT was more highly correlated with decreasing than with increasing changes in systolic BP (r = 0.83 ± 0.12 vs r = 0.68 ± 0.20; P = 0.001). The ROC curve analysis revealed that a 15% increase in PTT during anesthesia induction could detect a ≥30% decrease in systolic BP, with an area under the ROC curve of 0.85. Beat-to-beat PTT was fairly well correlated with invasive systolic BP and could predict a reduction in systolic BP during anesthesia induction. Beat-to-beat PTT may show potential as a useful noninvasive index of systolic BP when invasive BP is unavailable in high-risk hypertensive patients.

  15. Enhanced Electrical Integration of Engineered Human Myocardium via Intramyocardial versus Epicardial Delivery in Infarcted Rat Hearts.

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    Kaytlyn A Gerbin

    Full Text Available Cardiac tissue engineering is a promising approach to provide large-scale tissues for transplantation to regenerate the heart after ischemic injury, however, integration with the host myocardium will be required to achieve electromechanical benefits. To test the ability of engineered heart tissues to electrically integrate with the host, 10 million human embryonic stem cell (hESC-derived cardiomyocytes were used to form either scaffold-free tissue patches implanted on the epicardium or micro-tissue particles (~1000 cells/particle delivered by intramyocardial injection into the left ventricular wall of the ischemia/reperfusion injured athymic rat heart. Results were compared to intramyocardial injection of 10 million dispersed hESC-cardiomyocytes. Graft size was not significantly different between treatment groups and correlated inversely with infarct size. After implantation on the epicardial surface, hESC-cardiac tissue patches were electromechanically active, but they beat slowly and were not electrically coupled to the host at 4 weeks based on ex vivo fluorescent imaging of their graft-autonomous GCaMP3 calcium reporter. Histologically, scar tissue physically separated the patch graft and host myocardium. In contrast, following intramyocardial injection of micro-tissue particles and suspended cardiomyocytes, 100% of the grafts detected by fluorescent GCaMP3 imaging were electrically coupled to the host heart at spontaneous rate and could follow host pacing up to a maximum of 300-390 beats per minute (5-6.5 Hz. Gap junctions between intramyocardial graft and host tissue were identified histologically. The extensive coupling and rapid response rate of the human myocardial grafts after intramyocardial delivery suggest electrophysiological adaptation of hESC-derived cardiomyocytes to the rat heart's pacemaking activity. These data support the use of the rat model for studying electromechanical integration of human cardiomyocytes, and they

  16. The Effects of Female Sex Hormones on Ventricular Premature Beats and Repolarization Parameters in Physiological Menstrual Cycle.

    Science.gov (United States)

    Dogan, Mehmet; Yiginer, Omer; Uz, Omer; Kucuk, Ugur; Degirmencioglu, Gokhan; Isilak, Zafer; Uzun, Mehmet; Davulcu, Ezgi

    2016-05-01

    The effects of gender difference on cardiac electrophysiology have been well studied. In this study, we aimed to evaluate the effects of estradiol and progesteron changes occuring in physiological menstrual cycle on ventricular premature beats (VPBs) and cardiac repolarization parameters. Women of reproductive age with VPBs were included into the study group and healthy women were recruited as the control group. During the menstruation period, a 12-lead electrocardiography, blood samples, and 24-hour rhythm Holter were applied to the study group. Similarly, all tests were repeated in the estimated ovulation period (12-14 days before menstruation) by all cases. The study group consisted of 20 women patients with VPB, and the control group of 18 healthy women. While the number of VPB in the menstruation period was 210 beats/day (interquartile range [IQR]: 1,144), it decreased to 86 beats/day (IQR: 251) in the ovulation period with statistical significance (P < 0.05). Average heart rate in the menstruation period was 81.4 ± 10 beats/min and it significantly increased to 84.6 ± 8 beats/min in the ovulation period (P < 0.05). There were no differences in cardiac repolarization parameters in both menstruation and ovulation periods between the study and control groups. Comparing the menstruation and the ovulation periods, J-Tpeak interval, which reflects early repolarization, was shorter in the ovulation period (193 ± 27.7 ms and 201.1 ± 28.6 ms, respectively; P < 0.05). Other repolarization parameters did not show any significant difference. VPB frequency decreases with estradiol peak in the ovulation period. This suggests that estrogen may have protective effects against ventricular arrhythmias. ©2016 Wiley Periodicals, Inc.

  17. Caloric restriction and intermittent fasting alter spectral measures of heart rate and blood pressure variability in rats.

    Science.gov (United States)

    Mager, Donald E; Wan, Ruiqian; Brown, Martin; Cheng, Aiwu; Wareski, Przemyslaw; Abernethy, Darrell R; Mattson, Mark P

    2006-04-01

    Dietary restriction (DR) has been shown to increase life span, delay or prevent age-associated diseases, and improve functional and metabolic cardiovascular risk factors in rodents and other species. To investigate the effects of DR on beat-to-beat heart rate and diastolic blood pressure variability (HRV and DPV) in male Sprague-Dawley rats, we implanted telemetric transmitters and animals were maintained on either intermittent fasting (every other day feeding) or calorie-restricted (40% caloric reduction) diets. Using power spectral analysis, we evaluated the temporal profiles of the low- and high-frequency oscillatory components in heart rate and diastolic blood pressure signals to assess cardiac autonomic activity. Body weight, heart rate, and systolic and diastolic blood pressure were all found to decrease in response to DR. Both methods of DR produced decreases in the low-frequency component of DPV spectra, a marker for sympathetic tone, and the high-frequency component of HRV spectra, a marker for parasympathetic activity, was increased. These parameters required at least 1 month to become maximal, but returned toward baseline values rapidly once rats resumed ad libitum diets. These results suggest an additional cardiovascular benefit of DR that merits further studies of this potential effect in humans.

  18. Single-Beat Noninvasive Imaging of Ventricular Endocardial and Epicardial Activation in Patients Undergoing CRT

    Science.gov (United States)

    Berger, Thomas; Pfeifer, Bernhard; Hanser, Friedrich F.; Hintringer, Florian; Fischer, Gerald; Netzer, Michael; Trieb, Thomas; Stuehlinger, Markus; Dichtl, Wolfgang; Baumgartner, Christian; Pachinger, Otmar; Seger, Michael

    2011-01-01

    Background Little is known about the effect of cardiac resynchronization therapy (CRT) on endo- and epicardial ventricular activation. Noninvasive imaging of cardiac electrophysiology (NICE) is a novel imaging tool for visualization of both epi- and endocardial ventricular electrical activation. Methodology/Principal Findings NICE was performed in ten patients with congestive heart failure (CHF) undergoing CRT and in ten patients without structural heart disease (control group). NICE is a fusion of data from high-resolution ECG mapping with a model of the patient's individual cardiothoracic anatomy created from magnetic resonance imaging. Beat-to-beat endocardial and epicardial ventricular activation sequences were computed during native rhythm as well as during ventricular pacing using a bidomain theory-based heart model to solve the related inverse problem. During right ventricular (RV) pacing control patients showed a deterioration of the ventricular activation sequence similar to the intrinsic activation pattern of CHF patients. Left ventricular propagation velocities were significantly decreased in CHF patients as compared to the control group (1.6±0.4 versus 2.1±0.5 m/sec; pCHF patients showed right-to-left septal activation with the latest activation epicardially in the lateral wall of the left ventricle. Biventricular pacing resulted in a resynchronization of the ventricular activation sequence and in a marked decrease of total LV activation duration as compared to intrinsic conduction and RV pacing (129±16 versus 157±28 and 173±25 ms; both p<0.05). Conclusions/Significance Endocardial and epicardial ventricular activation can be visualized noninvasively by NICE. Identification of individual ventricular activation properties may help identify responders to CRT and to further improve response to CRT by facilitating a patient-specific lead placement and device programming. PMID:21298045

  19. Single-beat noninvasive imaging of ventricular endocardial and epicardial activation in patients undergoing CRT.

    Directory of Open Access Journals (Sweden)

    Thomas Berger

    Full Text Available BACKGROUND: Little is known about the effect of cardiac resynchronization therapy (CRT on endo- and epicardial ventricular activation. Noninvasive imaging of cardiac electrophysiology (NICE is a novel imaging tool for visualization of both epi- and endocardial ventricular electrical activation. METHODOLOGY/PRINCIPAL FINDINGS: NICE was performed in ten patients with congestive heart failure (CHF undergoing CRT and in ten patients without structural heart disease (control group. NICE is a fusion of data from high-resolution ECG mapping with a model of the patient's individual cardiothoracic anatomy created from magnetic resonance imaging. Beat-to-beat endocardial and epicardial ventricular activation sequences were computed during native rhythm as well as during ventricular pacing using a bidomain theory-based heart model to solve the related inverse problem. During right ventricular (RV pacing control patients showed a deterioration of the ventricular activation sequence similar to the intrinsic activation pattern of CHF patients. Left ventricular propagation velocities were significantly decreased in CHF patients as compared to the control group (1.6±0.4 versus 2.1±0.5 m/sec; p<0.05. CHF patients showed right-to-left septal activation with the latest activation epicardially in the lateral wall of the left ventricle. Biventricular pacing resulted in a resynchronization of the ventricular activation sequence and in a marked decrease of total LV activation duration as compared to intrinsic conduction and RV pacing (129±16 versus 157±28 and 173±25 ms; both p<0.05. CONCLUSIONS/SIGNIFICANCE: Endocardial and epicardial ventricular activation can be visualized noninvasively by NICE. Identification of individual ventricular activation properties may help identify responders to CRT and to further improve response to CRT by facilitating a patient-specific lead placement and device programming.

  20. Heart Health - Brave Heart

    Science.gov (United States)

    ... Bar Home Current Issue Past Issues Cover Story Heart Health Brave Heart Past Issues / Winter 2009 Table of Contents For ... you can have a good life after a heart attack." Lifestyle Changes Surviving—and thriving—after such ...

  1. Robotics and imaging in congenital heart surgery

    Science.gov (United States)

    Vasilyev, Nikolay V; Dupont, Pierre E; del Nido, Pedro J

    2012-01-01

    The initial success seen in adult cardiac surgery with the application of available robotic systems has not been realized as broadly in pediatric cardiac surgery. The main obstacles include extended set-up time and complexity of the procedures, as well as the large size of the instruments with respect to the size of the child. Moreover, while the main advantage of robotic systems is the ability to minimize incision size, for intracardiac repairs, cardiopulmonary bypass is still required. Catheter-based interventions, on the other hand, have expanded rapidly in both application as well as the complexity of procedures and lesions being treated. However, despite the development of sophisticated devices, robotic systems to aid catheter procedures have not been commonly applied in children. In this article, we describe new catheter-like robotic delivery platforms, which facilitate safe navigation and enable complex repairs, such as tissue approximation and fixation, and tissue removal, inside the beating heart. Additional features including the tracking of rapidly moving tissue targets and novel imaging approaches are described, along with a discussion of future prospects for steerable robotic systems. PMID:22413986

  2. Hydroxychloroquine reduces heart rate by modulating the hyperpolarization-activated current If: Novel electrophysiological insights and therapeutic potential.

    Science.gov (United States)

    Capel, Rebecca A; Herring, Neil; Kalla, Manish; Yavari, Arash; Mirams, Gary R; Douglas, Gillian; Bub, Gil; Channon, Keith; Paterson, David J; Terrar, Derek A; Burton, Rebecca-Ann B

    2015-10-01

    Bradycardic agents are of interest for the treatment of ischemic heart disease and heart failure, as heart rate is an important determinant of myocardial oxygen consumption. The purpose of this study was to investigate the propensity of hydroxychloroquine (HCQ) to cause bradycardia. We assessed the effects of HCQ on (1) cardiac beating rate in vitro (mice); (2) the "funny" current (If) in isolated guinea pig sinoatrial node (SAN) myocytes (1, 3, 10 µM); (3) heart rate and blood pressure in vivo by acute bolus injection (rat, dose range 1-30 mg/kg), (4) blood pressure and ventricular function during feeding (mouse, 100 mg/kg/d for 2 wk, tail cuff plethysmography, anesthetized echocardiography). In mouse atria, spontaneous beating rate was significantly (P rate (17% ± 6%, 1 μM dose) and a dose-dependent reduction in If (13% ± 3% at 1 µM; 19% ± 2% at 3 µM). Effects were also observed on L-type calcium ion current (ICaL) (12% ± 4% reduction) and rapid delayed rectifier potassium current (IKr) (35% ± 4%) at 3 µM. Intravenous HCQ decreased heart rate in anesthetized rats (14.3% ± 1.1% at 15mg/kg; n = 6) without significantly reducing mean arterial blood pressure. In vivo feeding studies in mice showed no significant change in systolic blood pressure nor left ventricular function. We have shown that HCQ acts as a bradycardic agent in SAN cells, in atrial preparations, and in vivo. HCQ slows the rate of spontaneous action potential firing in the SAN through multichannel inhibition, including that of If. Copyright © 2015 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.

  3. Reduced Dietary Sodium Intake Increases Heart Rate

    DEFF Research Database (Denmark)

    Graudal, Niels A; Hubeck-Graudal, Thorbjørn; Jürgens, Gesche

    2016-01-01

    Reduced dietary sodium intake (sodium reduction) increases heart rate in some studies of animals and humans. As heart rate is independently associated with the development of heart failure and increased risk of premature death a potential increase in heart rate could be a harmful side......-effect of sodium reduction. The purpose of the present meta-analysis was to investigate the effect of sodium reduction on heart rate. Relevant studies were retrieved from an updated pool of 176 randomized controlled trials (RCTs) published in the period 1973-2014. Sixty-three of the RCTs including 72 study...... populations reported data on heart rate. In a meta-analysis of these data sodium reduction increased heart rate with 1.65 beats per minute [95% CI: 1.19, 2.11], p heart rate. This effect was independent of baseline blood pressure. In conclusion sodium reduction...

  4. A moderate dose of propofol and rapidly induced mild hypothermia with extracorporeal lung and heart assist (ECLHA) improve the neurological outcome after prolonged cardiac arrest in dogs.

    Science.gov (United States)

    Ichinose, Keisuke; Okamoto, Taisuke; Tanimoto, Hironari; Taguchi, Hiroyuki; Tashiro, Masafumi; Sugita, Michiko; Takeya, Motohiro; Terasaki, Hidenori

    2006-08-01

    Propofol has been shown to protect against neuronal damage induced by brain ischaemia in small animal models. We reported previously that mild hypothermia (33 degrees C) in combination with extracorporeal lung and heart assist (ECLHA) improved the neurological outcome in dogs with cardiac arrest (CA) of 15 min induced during normothermia. In the present study, we investigated the neuroprotective effect of propofol infusion under mild hypothermia with ECLHA in this model. Twenty-one female dogs (15 mongrel dogs and 6 beagles) were divided into three groups: Midazolam 0.1 mg/(kg h) infusion group (M, n=7), Propofol 2 mg/(kg h) infusion group (P2, n=7), Propofol 4 mg/(kg h) infusion group (P4, n=7). Normothermic ventricular fibrillation (VF) was induced in all dogs for 15 min, followed by brief ECLHA and 168 h of intensive care. The drug infusion was initiated at a constant rate after the restoration of spontaneous circulation (ROSC) to 24 h. Mild hypothermia (33 degrees C) was maintained for 20 h. Neurological deficit scores (NDS: 0%=normal, 100%=brain death) were evaluated for neurological function from 33 to 168 h. One dog in the M group died, and the remaining dogs survived for 168 h. The P4 group showed better neurological recovery compared with the M group (48 h, 21+/-16% versus 32+/-15%; 72 h, 7+/-6% versus 25+/-11%; 96 h, 6+/-6% versus 21+/-6%; 120 h, 5+/-5% versus 20+/-6%; 144 h, 4+/-4% versus 20+/-6%; 168 h, 4+/-4% versus 20+/-6%, pdog in the P2 and three dogs in the P4 group achieved full neurological recovery (NDS: 0%). The number of intact pyramidal cells in the hippocampal CA1 was greater in the propofol groups than midazolam group (p<0.05). The combination of propofol infusion at a rate of 4 mg/(kg h), 24h and rapidly induced mild hypothermia (33 degrees C) with ECLHA might provide a successful means of cerebral resuscitation from CA.

  5. Beat Rate Variability in Murine Embryonic Stem Cell-Derived Cardiomyocytes: Effect of Antiarrhythmic Drugs.

    Science.gov (United States)

    Niehoff, Julius; Matzkies, Matthias; Nguemo, Filomain; Hescheler, Jürgen; Reppel, Michael

    2016-01-01

    Heart rate variability (HRV) refers to the fluctuation of the time interval between consecutive heartbeats in humans. It has recently been discovered that cardiomyocytes derived from human embryonic and induced pluripotent stem cells show beat rate variability (BRV) that is similar to the HRV in humans. In the present study, clinical aspects of HRV were transferred to an in vitro model. The aims of the study were to explore the BRV in murine embryonic stem cell (mESC)-derived cardiomyocytes and to demonstrate the influence of antiarrhythmic drugs on BRV as has been shown in clinical trials previously. The Microelectrode Array (MEA) technique was used to perform short-term recordings of extracellular field potentials (FPs) of spontaneously beating cardiomyocytes derived from mESCs (D3 cell line, αPig-44). Offline analysis was focused on time domain and nonlinear methods. The Poincaré-Plot analysis of measurements without pharmacological intervention revealed that three different shapes of scatter plots occurred most frequently. Comparable shapes have been described in clinical studies before. The antiarrhythmic drugs Ivabradine, Verapamil and Sotalol augmented BRV, whereas Flecainide decreased BRV parameters at low concentrations (SDSD 79.0 ± 8.7% of control at 10(-9) M, p < 0.05) and increased variability measures at higher concentrations (SDNN 258.8 ± 42.7% of control at 10(-5) M, p < 0.05). Amiodarone and Metoprolol did not alter BRV significantly. Spontaneously beating cardiomyocytes derived from mESCs showed BRV that appears to be similar to the HRV known from humans. Antiarrhythmic drugs affected BRV parameters similar to clinical observations. Therefore, our study demonstrates that this in vitro model can contribute to a better understanding of electrophysiological properties of mESC-derived cardiomyocytes and might serve as a valuable tool for drug safety screening. © 2016 The Author(s) Published by S. Karger AG, Basel.

  6. Beat Rate Variability in Murine Embryonic Stem Cell-Derived Cardiomyocytes: Effect of Antiarrhythmic Drugs

    Directory of Open Access Journals (Sweden)

    Julius Niehoff

    2016-02-01

    Full Text Available Background/Aims: Heart rate variability (HRV refers to the fluctuation of the time interval between consecutive heartbeats in humans. It has recently been discovered that cardiomyocytes derived from human embryonic and induced pluripotent stem cells show beat rate variability (BRV that is similar to the HRV in humans. In the present study, clinical aspects of HRV were transferred to an in vitro model. The aims of the study were to explore the BRV in murine embryonic stem cell (mESC-derived cardiomyocytes and to demonstrate the influence of antiarrhythmic drugs on BRV as has been shown in clinical trials previously. Methods: The Microelectrode Array (MEA technique was used to perform short-term recordings of extracellular field potentials (FPs of spontaneously beating cardiomyocytes derived from mESCs (D3 cell line, αPig-44. Offline analysis was focused on time domain and nonlinear methods. Results: The Poincaré-Plot analysis of measurements without pharmacological intervention revealed that three different shapes of scatter plots occurred most frequently. Comparable shapes have been described in clinical studies before. The antiarrhythmic drugs Ivabradine, Verapamil and Sotalol augmented BRV, whereas Flecainide decreased BRV parameters at low concentrations (SDSD 79.0 ± 8.7% of control at 10-9 M, p -5 M, p Conclusions: Spontaneously beating cardiomyocytes derived from mESCs showed BRV that appears to be similar to the HRV known from humans. Antiarrhythmic drugs affected BRV parameters similar to clinical observations. Therefore, our study demonstrates that this in vitro model can contribute to a better understanding of electrophysiological properties of mESC-derived cardiomyocytes and might serve as a valuable tool for drug safety screening.

  7. Unobtrusive heart rate monitor based on a fiber specklegram sensor and a single-board computer

    Science.gov (United States)

    Benevides, Alessandro B.; Frizera, Anselmo; Cotrina, Anibal; Ribeiro, Moisés. R. N.; Segatto, Marcelo E. V.; Pontes, Maria José

    2015-09-01

    This paper proposes a portable and unobtrusive heart rate monitor based on fiber specklegram sensors. The proposed module uses the Raspberry Pi module to perform the image acquisition and the fiber specklegram sensor, which is based on multimode plastic optical fibers. The heart rate is obtained by welch power spectral density estimate and the heart beats are identified by means of a threshold analysis.

  8. Heart Rates of High School Physical Education Students during Team Sports, Individual Sports, and Fitness Activities

    Science.gov (United States)

    Laurson, Kelly R.; Brown, Dale D.; Cullen, Robert W.; Dennis, Karen K.

    2008-01-01

    This study examined how activity type influenced heart rates and time spent in target heart rate zones of high school students participating in physical education classes. Significantly higher average heart rates existed for fitness (142 plus or minus 24 beats per minute [bpm]) compared to team (118 plus or minus 24 bpm) or individual (114 plus or…

  9. Resting heart rate, heart rate variability and functional decline in old age

    DEFF Research Database (Denmark)

    Ogliari, Giulia; Mahinrad, Simin; Stott, David J

    2015-01-01

    BACKGROUND: Heart rate and heart rate variability, markers of cardiac autonomic function, have been linked with cardiovascular disease. We investigated whether heart rate and heart rate variability are associated with functional status in older adults, independent of cardiovascular disease. METHODS......: We obtained data from the Prospective Study of Pravastatin in the Elderly at Risk (PROSPER). A total of 5042 participants were included in the present study, and mean followup was 3.2 years. Heart rate and heart rate variability were derived from baseline 10-second electrocardiograms. Heart rate.......3 years. At baseline, higher heart rate was associated with worse ADL and IADL, and lower SDNN was related to worse IADL (all p values heart rate (range 71-117 beats/min) had a 1.79-fold (95% confidence interval [CI] 1.45-2.22) and 1.35-fold (95% CI 1...

  10. Tonic arterial chemoreceptor activity contributes to cardiac sympathetic activation in mild ovine heart failure.

    Science.gov (United States)

    Xing, Daniel T; May, Clive N; Booth, Lindsea C; Ramchandra, Rohit

    2014-08-01

    Heart failure (HF) is associated with a large increase in cardiac sympathetic nerve activity (CSNA), which has detrimental effects on the heart and promotes arrhythmias and sudden death. There is increasing evidence that arterial chemoreceptor activation plays an important role in stimulating renal sympathetic nerve activity (RSNA) and muscle sympathetic nerve activity in HF. Given that sympathetic nerve activity to individual organs is differentially controlled, we investigated whether tonic arterial chemoreceptor activation contributes to the increased CSNA in HF. We recorded CSNA and RSNA in conscious normal sheep and in sheep with mild HF induced by rapid ventricular pacing (ejection fraction chemoreceptor function was evaluated by supplementing room air with 100% intranasal oxygen (2-3 l min(-1)) for 20 min, thereby deactivating chemoreceptors. The effects of hyperoxia on resting levels and baroreflex control of heart rate, CSNA and RSNA were determined. In HF, chemoreceptor deactivation induced by hyperoxia significantly reduced CSNA [90 ± 2 versus 75 ± 5 bursts (100 heart beats)(-1), P chemoreceptor deactivation reduced heart rate without a significant effect on CSNA or RSNA. In summary, deactivation of peripheral chemoreceptors during HF reduced the elevated levels of CSNA, indicating that tonic arterial chemoreceptor activation plays a critical role in stimulating the elevated CSNA in HF. © 2014 The Authors. Experimental Physiology © 2014 The Physiological Society.

  11. Small molecule screening platform for assessment of cardiovascular toxicity on adult zebrafish heart

    Directory of Open Access Journals (Sweden)

    Kitambi Satish

    2012-03-01

    Full Text Available Abstract Background Cardiovascular toxicity is a major limiting factor in drug development and requires multiple cost-effective models to perform toxicological evaluation. Zebrafish is an excellent model for many developmental, toxicological and regenerative studies. Using approaches like morpholino knockdown and electrocardiogram, researchers have demonstrated physiological and functional similarities between zebrafish heart and human heart. The close resemblance of the genetic cascade governing heart development in zebrafish to that of humans has propelled the zebrafish system as a cost-effective model to conduct various genetic and pharmacological screens on developing embryos and larvae. The current report describes a methodology for rapid isolation of adult zebrafish heart, maintenance ex vivo, and a setup to perform quick small molecule throughput screening, including an in-house implemented analysis script. Results Adult zebrafish were anesthetized and after rapid decapitation the hearts were isolated. The short time required for isolation of hearts allows dissection of multiple fishes, thereby obtaining a large sample size. The simple protocol for ex vivo culture allowed maintaining the beating heart for several days. The in-house developed script and spectral analyses allowed the readouts to be presented either in time domain or in frequency domain. Taken together, the current report offers an efficient platform for performing cardiac drug testing and pharmacological screens. Conclusion The new methodology presents a fast, cost-effective, sensitive and reliable method for performing small molecule screening. The variety of readouts that can be obtained along with the in-house developed analyses script offers a powerful setup for performing cardiac toxicity evaluation by researchers from both academics and industry.

  12. Heart rate monitors and abnormal heart rhythm detection.

    Science.gov (United States)

    Boudet, G; Chamoux, A

    2000-10-01

    We test the accuracy of two third generation heart rate monitors (HRM), Accurex Plus and Vantage NV and compare these data with those of an older monitor, PE 4000. Then we investigate responses of the HRM's to abnormal heart rhythms (HR). Accurex Plus and Vantage NV, and PE 4000 were tested in the laboratory under both stable and transient conditions. The Phantom 320 HR simulator gave 7 stable heart rates, each lasting 3 min. The responses of the HRM's to abnormal heart rhythms were tested with an automatic arrhythmia program lasting 17 min. The new HRM's, Accurex Plus and Vantage NV, were more accurate (89 to 94% and over 98% at +/-3 beats per min) in the stable state than the PE 4000. They all showed a smoothing effect in transient measurements, which was stronger in decelerating HR (1st case) than in accelerating HR (2nd case). - 1st case: Accurex Plus =Vantage NV >PE 4000 -2nd case: PE 4000 >Accurex =Vantage. Most isolated heart rhythm disorders (missing beat, pause 4 s, important bradycardia or tachycardia.

  13. A Structural Basis for How Motile Cilia Beat

    Science.gov (United States)

    Satir, Peter; Heuser, Thomas; Sale, Winfield S.

    2014-01-01

    The motile cilium is a mechanical wonder, a cellular nanomachine that produces a high-speed beat based on a cycle of bends that move along an axoneme made of 9+2 microtubules. The molecular motors, dyneins, power the ciliary beat. The dyneins are compacted into inner and outer dynein arms, whose activity is highly regulated to produce microtubule sliding and axonemal bending. The switch point hypothesis was developed long ago to account for how sliding in the presence of axonemal radial spoke–central pair interactions causes the ciliary beat. Since then, a new genetic, biochemical, and structural complexity has been discovered, in part, with Chlamydomonas mutants, with high-speed, high-resolution analysis of movement and with cryoelectron tomography. We stand poised on the brink of new discoveries relating to the molecular control of motility that extend and refine our understanding of the basic events underlying the switching of arm activity and of bend formation and propagation. PMID:26955066

  14. Heart MRI

    Science.gov (United States)

    Magnetic resonance imaging - cardiac; Magnetic resonance imaging - heart; Nuclear magnetic resonance - cardiac; NMR - cardiac; MRI of the heart; Cardiomyopathy - MRI; Heart failure - MRI; Congenital heart disease - MRI

  15. Ivabradine in stable coronary artery disease without clinical heart failure

    DEFF Research Database (Denmark)

    Fox, Kim; Ford, Ian; Steg, Philippe Gabriel

    2014-01-01

    BACKGROUND: An elevated heart rate is an established marker of cardiovascular risk. Previous analyses have suggested that ivabradine, a heart-rate-reducing agent, may improve outcomes in patients with stable coronary artery disease, left ventricular dysfunction, and a heart rate of 70 beats per...... minute or more. METHODS: We conducted a randomized, double-blind, placebo-controlled trial of ivabradine, added to standard background therapy, in 19,102 patients who had both stable coronary artery disease without clinical heart failure and a heart rate of 70 beats per minute or more (including 12...... without activity-limiting angina (P=0.02 for interaction). The incidence of bradycardia was higher with ivabradine than with placebo (18.0% vs. 2.3%, Pdisease without clinical heart failure, the addition of ivabradine to standard...

  16. Open-source, vendor-independent, automated multi-beat tissue Doppler echocardiography analysis.

    Science.gov (United States)

    Dhutia, Niti M; Zolgharni, Massoud; Mielewczik, Michael; Negoita, Madalina; Sacchi, Stefania; Manoharan, Karikaran; Francis, Darrel P; Cole, Graham D

    2017-08-01

    Current guidelines for measuring cardiac function by tissue Doppler recommend using multiple beats, but this has a time cost for human operators. We present an open-source, vendor-independent, drag-and-drop software capable of automating the measurement process. A database of ~8000 tissue Doppler beats (48 patients) from the septal and lateral annuli were analyzed by three expert echocardiographers. We developed an intensity- and gradient-based automated algorithm to measure tissue Doppler velocities. We tested its performance against manual measurements from the expert human operators. Our algorithm showed strong agreement with expert human operators. Performance was indistinguishable from a human operator: for algorithm, mean difference and SDD from the mean of human operators' estimates 0.48 ± 1.12 cm/s (R 2  = 0.82); for the humans individually this was 0.43 ± 1.11 cm/s (R 2  = 0.84), -0.88 ± 1.12 cm/s (R 2  = 0.84) and 0.41 ± 1.30 cm/s (R 2  = 0.78). Agreement between operators and the automated algorithm was preserved when measuring at either the edge or middle of the trace. The algorithm was 10-fold quicker than manual measurements (p Doppler traces as accurately as human experts. This automation permits rapid, bias-resistant multi-beat analysis from spectral tissue Doppler images.

  17. BIOPHYSICAL CHARACTERISATION OF THE UNDER-APPRECIATED AND IMPORTANT RELATIONSHIP BETWEEN HEART RATE VARIABILITY AND HEART RATE

    Science.gov (United States)

    Monfredi, Oliver; Lyashkov, Alexey E; Johnsen, Anne-Berit; Inada, Shin; Schneider, Heiko; Wang, Ruoxi; Nirmalan, Mahesh; Wisloff, Ulrik; Maltsev, Victor A; Lakatta, Edward G; Zhang, Henggui; Boyett, Mark R

    2014-01-01

    Heart rate variability (beat-to-beat changes in the RR interval) has attracted considerable attention over the last 30+ years (PubMed currently lists >17,000 publications). Clinically, a decrease in heart rate variability is correlated to higher morbidity and mortality in diverse conditions, from heart disease to foetal distress. It is usually attributed to fluctuation in cardiac autonomic nerve activity. We calculated heart rate variability parameters from a variety of cardiac preparations (including humans, living animals, Langendorff-perfused heart and single sinoatrial nodal cell) in diverse species, combining this with data from previously published papers. We show that regardless of conditions, there is a universal exponential decay-like relationship between heart rate variability and heart rate. Using two biophysical models, we develop a theory for this, and confirm that heart rate variability is primarily dependent on heart rate and cannot be used in any simple way to assess autonomic nerve activity to the heart. We suggest that the correlation between a change in heart rate variability and altered morbidity and mortality is substantially attributable to the concurrent change in heart rate. This calls for re-evaluation of the findings from many papers that have not adjusted properly or at all for heart rate differences when comparing heart rate variability in multiple circumstances. PMID:25225208

  18. Analysis of ependymal ciliary beat pattern and beat frequency using high speed imaging: comparison with the photomultiplier and photodiode methods.

    Science.gov (United States)

    O'Callaghan, Chris; Sikand, Kulvinder; Chilvers, Mark A

    2012-06-07

    The aim of this study was to compare beat frequency measurements of ependymal cilia made by digital high speed imaging to those obtained using the photomultiplier and modified photodiode techniques. Using high speed video analysis the relationship of the power and recover strokes was also determined. Ciliated strips of ependyma attached to slices from the brain of Wistar rats were incubated at 30°C and observed using a ×50 water immersion lens. Ciliary beat frequency was measured using each of the three techniques: the high speed video, photodiode and photomultiplier. Readings were repeated after 30 minutes incubation at 37°C. Ependymal cilia were observed in slow motion and the precise movement of cilia during the recovery stroke relative to the path travelled during the power stroke was measured. The mean (95% confidence intervals) beat frequencies determined by the high speed video, photomultiplier and photodiode at 30°C were 27.7 (26.6 to 28.8), 25.5 (24.4 to 26.6) and 20.8 (20.4 to 21.3) Hz, respectively. The mean (95% confidence intervals) beat frequencies determined by the high speed video, photomultiplier and photodiode at 37°C were 36.4 (34 to 39.5), 38.4 (36.8 to 39.9) and 18.8 (16.9 to 20.5) Hz. The inter and intra observer reliability for measurement of ciliary beat frequency was 3.8% and 1%, respectively. Ependymal cilia were observed to move in a planar fashion during the power and recovery strokes with a maximum deviation to the right of the midline of 12.1(11.8 to 13.0)° during the power stroke and 12.6(11.6 to 13.6)° to the left of the midline during the recovery stroke. The photodiode technique greatly underestimates ciliary beat frequency and should not be used to measure ependymal ciliary beat frequency at the temperatures studied. Ciliary beat frequency from the high speed video and photomultiplier techniques cannot be used interchangeably. Ependymal cilia had minimal deviation to the right side during their power stroke and to the left

  19. Beat-to-beat variability of QT intervals is increased in patients with drug-induced long-QT syndrome

    DEFF Research Database (Denmark)

    Hinterseer, Martin; Thomsen, Morten Bækgaard; Beckmann, Britt-Maria

    2008-01-01

    Torsades de pointes arrhythmias (TdP) occur by definition in the setting of prolonged QT intervals. Animal models of drug induced Long-QT syndrome (dLQTS) have shown higher predictive value for proarrhythmia with beat-to-beat variability of repolarization duration (BVR) when compared with QT...... intervals. Here, we evaluate variability of QT intervals in patients with a history of drug-induced long QT syndrome (dLQTS) and TdP in absence of a mutation in any of the major LQTS genes....

  20. The brain responses to different frequencies of binaural beat sounds on QEEG at cortical level.

    Science.gov (United States)

    Jirakittayakorn, Nantawachara; Wongsawat, Yodchanan

    2015-01-01

    Beat phenomenon is occurred when two slightly different frequency waves interfere each other. The beat can also occur in the brain by providing two slightly different frequency waves separately each ear. This is called binaural beat. The brain responses to binaural beat are in discussion process whether the brain side and the brain area. Therefore, this study aims to figure out the brain responses to binaural beat by providing different binaural beat frequencies on 250 carrier tone continuously for 30 minutes to participants and using quantitative electroencephalography (QEEG) to interpret the data. The result shows that different responses appear in different beat frequency. Left hemisphere dominance occur in 3 Hz beat within 15 minutes and 15 Hz beat within 5 minutes. Right hemisphere dominance occurs in 10 Hz beat within 25 minute. 6 Hz beat enhances all area of the brain within 10 minutes. 8 Hz and 25 Hz beats have no clearly responses while 40 Hz beat enhances the responses in frontal lobe. These brain responses can be used for brain modulation application to induce the brain activity in further studies.

  1. Effects of ankylosing spondylitis on the heart.

    Science.gov (United States)

    Gunes, Yilmaz; Tuncer, Mustafa; Guntekin, Unal; Sahin, Musa; Yazmalar, Levent

    2009-06-01

    Various cardiac pathologies have been linked to ankylosing spondylitis (AS) in various conflicting reports. A pilot exploration is done to search frequencies of structural heart involvement, arrhythmias and heart rate variability (HRV) in AS patients. Thirty-five AS patients and 25 healthy people were evaluated with 12-lead electrocardiography, echocardiography and 24-hour Holter monitoring. No patient had significant valvular heart disease except one. Ventricular and supraventricular premature beat counts were significantly higher in AS patients compared to the control group (P = 0.002 and 0.01). Frequency of ventricular premature beats was significantly correlated with isovolumetric relaxation time (IVRT) (r = 0.291 , P = 0.025). Abnormal ECG was defined in 4 AS patients; 2 incomplete right bundle-branch block (RBBB), one left axis deviation and one complete RBBB and left anterior hemiblock. QT and P wave dispersions were not significantly different between AS patients and the control group. Although mitral inflow deceleration time (DT) and IVRT were significantly longer in AS patients (P SDSD (day and night time) were significantly lower than the control group. There were weak to moderate but significant negative correlations of IVRT and DT with these parameters. In this small sample there is no significant increase in structural heart disease in patients with AS. Diastolic functions may be affected in the course of disease and this may be associated with increased frequency of premature beats. Day time heart rate variability is decreased and associated with diastolic function parameters of IVRT and DT in AS patients.

  2. Increased heart rate is associated with a prothrombotic state: The Framingham Heart Study.

    Science.gov (United States)

    Tofler, Geoffrey H; Massaro, Joseph; Levy, Daniel A; Sutherland, Patrice A; Buckley, Thomas; D'Agostino, Ralph B

    2017-03-01

    Background Although a higher heart rate is associated with an increased risk of cardiovascular disease, the mechanism is not well understood. As thrombosis has an important role in plaque development and acute coronary syndromes, the increase related to heart rate may result from a prothrombotic imbalance. Methods We investigated the relation between heart rate and thrombotic potential in 3451 participants from the Offspring Cohort of the Framingham Heart Study (mean age 54 years, 55% women). Participants were divided into quintiles based on heart rate derived from a resting electrocardiogram. Results Higher heart rates were associated with significant age-adjusted increases in fibrinogen, viscosity, factor VII antigen, and impaired fibrinolytic potential (plasminogen activator inhibitor and tissue plasminogen activator antigen) among men and women, and von Willebrand factor antigen among men. Fibrinogen levels were 9% higher among men with a heart rate of 80.9 ± 8.1 beats/min (quintile 5) vs. 50.0 ± 3.9 beats/min (quintile 1) (314 vs. 287 mg/dl, p heart rates are associated with a prothrombotic state. Because these factors are also associated with endothelial dysfunction and inflammation, these findings are consistent with an injurious effect of higher heart rates on the endothelium. Measures to reduce thrombotic potential may be of particular value in people with higher heart rates.

  3. Using Science and Much More to Beat the Flood

    Science.gov (United States)

    Seeley, Claire

    2014-01-01

    The Beat the Flood challenge involves designing and building a model flood-proof home, which is then tested in "flood" conditions. It is set on the fictitious Watu Island. The children form teams, with each team member being assigned a responsibility for the duration of the task--team leader, chief recorder, and resource manager. This…

  4. System-Beating: Structural Impediments to the Public Good.

    Science.gov (United States)

    Rosner, Lydia S.

    1993-01-01

    Suggests that within bureaucratic systems norms of behavior develop that can be classified as system-beating. Examines elements necessary for such behavior to occur: individual with role within system; system comprised of many specific roles; observation of practical actions and practical circumstances; interpretation of these circumstances;…

  5. Struggling Readers: High-Poverty Schools that Beat the Odds

    Science.gov (United States)

    Cunningham, Patricia M.

    2006-01-01

    Poverty is a strong predictor of lack of academic success in reading, and schools serving high-poverty populations are more likely to show weak performance in high-stakes tests. But some schools manage to beat these odds, with students outperforming peers from more advantaged neighborhoods. Why? The author showcases six high-poverty schools where…

  6. Wife beating amongst Africans as a challenge to pastoral care

    Directory of Open Access Journals (Sweden)

    Magezi E. Baloyi

    2013-11-01

    Full Text Available Traditional African people are known for respecting their marriage. Even though marriage is so highly regarded, it is astonishing to realise that wife beating has become an extremely common practice amongst them. It therefore becomes an important research question to ask about the extent to which deeply-seated traditional customs regarding wife beating as a form of stamping down authority and of trying to keep the household in order, will have to be confronted with what is deemed to be good practice from the perspective of the law, community and pastoral caregivers. There are women who live with scars on their faces and bodies, having been beaten by their husbands. Although there are many forms of abuse towards women in family situations, this article aims particularly to focus on wife beating that is practiced for traditional as well as other related reasons. This research will involve itself with establishing whether the reasons for wife beating are part of the traditional system for keeping the household in order and interrogate both legal and pastoral interventions that attempt to eliminate or avoid such behaviour.

  7. Efficiency of brainwave entrainment by binaural beats in reducing anxiety

    Directory of Open Access Journals (Sweden)

    Ahmad Alipoor

    2014-04-01

    Full Text Available Background: Anxiety is a fundamental phenomenon that is a common symptom in all mental disorders. The aim of the present study was to assess the effect of brainwave entrainment on anxiety reduction using binaural beats. Methods: In this experimental double-blind study, 30 employees were selected from an engineering research firm through random sampling and replacement and divided into two groups: control group and experimental group. All participants completed the Spielberger’s State-Trait Anxiety Inventory (STAI. Then, the experimental group listened to binaural beats which was recorded on a non-vocal piece of music for 4 weeks, 3 sessions each week. Each session lasted about 20 minutes. At the same time, the control group listened to the background music without any entrainment sound. At the end, both groups completed the anxiety questionnaire and the anxiety scores of both groups obtained before and after intervention were analyzed by ANCOVA. Results: The findings showed that the brainwave entrainment using binaural beats led to the significant reduction of state anxiety (P<0.001 and trait anxiety (P<0.018. Conclusion: Brainwave entrainment using binaural beats is an effective factor in decreasing state and trait anxiety; so, it can be used to reduce anxiety in mental health centers.

  8. Arrhythmogenesis by single ectopic beats originating in the Purkinje system

    Science.gov (United States)

    Deo, Makarand; Boyle, Patrick M.; Kim, Albert M.

    2010-01-01

    Cells in the Purkinje system (PS) are known to be more vulnerable than ventricular myocytes to secondary excitations during the action potential (AP) plateau or repolarization phases, known as early afterdepolarizations (EADs). Since myocytes have a lower intrinsic AP duration than the PS cells to which they are coupled, EADs occurring in distal branches of the PS are more likely to result in propagating ectopic beats. In this study, we use a computer model of the rabbit ventricles and PS to investigate the consequences of EADs occurring at different times and places in the cardiac conduction system. We quantify the role of tissue conductivity and excitability, as well as interaction with sinus excitation, in determining whether an EAD-induced ectopic beat will establish reentrant activity. We demonstrate how a single ectopic beat arising from an EAD in the distal PS can give rise to reentrant arrhythmia; in contrast, EADs in the proximal PS were unable to initiate reentry. Clinical studies have established the PS as a potential substrate for reentry, but the underlying mechanisms of these types of disorder are not well understood, nor are conditions leading to their development clearly defined; this work provides new insights into the role of the PS in such circumstances. Our findings indicate that simulated EADs in the distal PS can induce premature beats, which can lead to the tachycardias involving the conduction system due to interactions with sinus activity or impaired myocardial conduction velocity. PMID:20622103

  9. Failure of right atrial premature beats to reset atriofascicular tachycardia.

    Science.gov (United States)

    Porkolab, F L; Alpert, B L; Scheinman, M M

    1999-03-01

    A patient with a right atriofascicular (Mahaim) tachycardia was found to have inducible antidromic supraventricular tachycardia, but atrial premature beats from the right atrial free wall failed to reset the tachycardia. An interesting transition from AV nodal reentry tachycardia to Mahaim tachycardia is also presented.

  10. Popular Music in Southeast Asia : Banal Beats, Muted Histories

    NARCIS (Netherlands)

    Barendregt, Bart; Keppy, Peter; Schulte Nordholt, Henk

    2017-01-01

    'Popular Music in Southeast Asia: Banal Beats, Muted Histories' offers a cultural history of modern Southeast Asia from the original vantage point of popular music since the 1920s up to the present. By creatively connecting indigenous musical styles with foreign musical genres, Southeast Asians

  11. Subdividing the beat: auditory and motor contributions to synchronization

    NARCIS (Netherlands)

    Loehr, J.D.; Palmer, C.

    2009-01-01

    THE CURRENT STUDY EXAMINED HOW AUDITORY AND kinematic information influenced pianists' ability to synchronize musical sequences with a metronome. Pianists performed melodies in which quarter-note beats were subdivided by intervening eighth notes that resulted from auditory information (heard tones),

  12. Music and the heart.

    Science.gov (United States)

    Koelsch, Stefan; Jäncke, Lutz

    2015-11-21

    Music can powerfully evoke and modulate emotions and moods, along with changes in heart activity, blood pressure (BP), and breathing. Although there is great heterogeneity in methods and quality among previous studies on effects of music on the heart, the following findings emerge from the literature: Heart rate (HR) and respiratory rate (RR) are higher in response to exciting music compared with tranquilizing music. During musical frissons (involving shivers and piloerection), both HR and RR increase. Moreover, HR and RR tend to increase in response to music compared with silence, and HR appears to decrease in response to unpleasant music compared with pleasant music. We found no studies that would provide evidence for entrainment of HR to musical beats. Corresponding to the increase in HR, listening to exciting music (compared with tranquilizing music) is associated with a reduction of heart rate variability (HRV), including reductions of both low-frequency and high-frequency power of the HRV. Recent findings also suggest effects of music-evoked emotions on regional activity of the heart, as reflected in electrocardiogram amplitude patterns. In patients with heart disease (similar to other patient groups), music can reduce pain and anxiety, associated with lower HR and lower BP. In general, effects of music on the heart are small, and there is great inhomogeneity among studies with regard to methods, findings, and quality. Therefore, there is urgent need for systematic high-quality research on the effects of music on the heart, and on the beneficial effects of music in clinical settings. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2015. For permissions please email: journals.permissions@oup.com.

  13. Heart rate recovery and heart rate variability are unchanged in patients with coronary artery disease following 12 weeks of high-intensity interval and moderate-intensity endurance exercise training.

    Science.gov (United States)

    Currie, Katharine D; Rosen, Lee M; Millar, Philip J; McKelvie, Robert S; MacDonald, Maureen J

    2013-06-01

    Decreased heart rate variability and attenuated heart rate recovery following exercise are associated with an increased risk of mortality in cardiac patients. This study investigated the effects of 12 weeks of moderate-intensity endurance exercise (END) and a novel low-volume high-intensity interval exercise protocol (HIT) on measures of heart rate recovery and heart rate variability in patients with coronary artery disease (CAD). Fourteen males with CAD participated in 12 weeks of END or HIT training, each consisting of 2 supervised exercise sessions per week. END consisted of 30-50 min of continuous cycling at 60% peak power output (PPO). HIT involved ten 1-min intervals at 88% PPO separated by 1-min intervals at 10% PPO. Heart rate recovery at 1 min and 2 min was measured before and after training (pre- and post-training, respectively) using a submaximal exercise bout. Resting time and spectral and nonlinear domain measures of heart rate variability were calculated. Following 12 weeks of END and HIT, there was no change in heart rate recovery at 1 min (END, 40 ± 12 beats·min(-1) vs. 37 ± 19 beats·min(-1); HIT, 31 ± 8 beats·min(-1) vs. 35 ± 8 beats·min(-1); p ≥ 0.05 for pre- vs. post-training) or 2 min (END, 44 ± 18 beats·min(-1) vs. 43 ± 19 beats·min(-1); HIT, 42 ± 10 beats·min(-1) vs. 50 ± 6 beats·min(-1); p ≥ 0.05 for pre- vs. post-training). All heart rate variability indices were unchanged following END and HIT training. In conclusion, neither END nor HIT exercise programs elicited training-induced improvements in cardiac autonomic function in patients with CAD. The absence of improvements with training may be attributed to the optimal medical management and normative pretraining state of our sample.

  14. Heart murmurs

    Science.gov (United States)

    Chest sounds - murmurs; Heart sounds - abnormal; Murmur - innocent; Innocent murmur; Systolic heart murmur; Diastolic heart murmur ... The heart has 4 chambers: Two upper chambers (atria) Two lower chambers (ventricles) The heart has valves that close ...

  15. Beat-to-beat blood-pressure measurements applied in studies on mental workload

    NARCIS (Netherlands)

    van Roon, A.M.; Mulder, L.J.M.; Veldman, J.B.P.; Mulder, G.

    1995-01-01

    Heart rate variability diminishes during mental task performance. This decrease can be related to a change in control of the autonomic nervous system of blood pressure. This change in sympathetic/parasympathetic balance might be caused by a decrease in baroreflex sensitivity. - To study the

  16. The Beat to Read: A Cross-lingual Link between Rhythmic Regularity Perception and Reading Skill.

    Directory of Open Access Journals (Sweden)

    Annike Bekius

    2016-08-01

    Full Text Available This work assesses one specific aspect of the relationship between auditory rhythm cognition and language skill: regularity perception. In a group of 26 adult participants, native speakers of 11 different native languages, we demonstrate a strong and significant correlation between the ability to detect a ‘roughly’ regular beat and rapid automatized naming (RAN as a measure of language skill (Spearman’s rho, -0.47, p <0.01. This correlation remains significant after accounting for differences in non-verbal IQ (rho, -0.37, p <0.05, and musical expertise in addition (rho, -0.31, p <0.05. There was no such robust relationship for the ‘mirror image’ task of irregularity detection, i.e. the ability to detect ongoing small deviations from a regular beat. This dissociation in correlation was confirmed after accounting for shared variance between the two rhythm tasks. Whilst being consistent with the ‘shared resources model’ in terms of rhythm as a common basis of language and music, evolutionarily as well as in individual development, the results also document how two related rhythm processing abilities relate differentially to language skill. Specifically, the results support a universal relationship between rhythmic regularity detection and reading skill that is robust to accounting for differences in fluid intelligence and musical expertise, and transcends language-specific differences in speech rhythm.

  17. Mechanoelectric feedback does not contribute to the Frank-Starling relation in the rat and guinea pig heart

    Directory of Open Access Journals (Sweden)

    D Kelly

    2014-12-01

    Full Text Available Mechanoelectric feedback (MEF is the process by which mechanical forces on the myocardium can alter its electrical properties. The effect can be large enough to induce ectopic beats or fibrillation. However, the role of MEF at physiological levels of mechanical stress is not clear. We have investigated alteration in action potential morphology in rat and guinea pig ventricle and in rat atrial tissue at levels of stretch near the plateau of the Frank-Starling curve. Stretch of >100 mm.Hg End Diastolic Left Ventricular Pressure (EDLVP or rapidly applied stretch (EDLVP increased by 25 mm.Hg within 100 ms often triggered ectopic beats in isolated rat and guinea-pig hearts. However, ventricular epicardial monophasic action potentials (MAPs recorded during stretch to EDLVP up to 30 mm. Hg showed no consistent changes in action potential duration (at APD20, APD50 or APD80 in either species. MAP recording detected APD prolongation with very small concentrations of 4-AP (10 μM, confirming the discrimination of the recording technique. In isolated rat atrial strips, no changes in intracellular action potential morphology or membrane potential were seen when stretched to levels producing an optimum increase in contractility. We conclude that alteration in action potential morphology with stretch does not contribute to the Frank-Starling relation in ventricle of rat or guinea-pig isolated heart, or in rat atrial tissue.

  18. Rapid detection of aneuploidy and unbalanced chromosomal rearrangements by subtelomeric multiplex ligation-dependent probe amplification in fetuses with congenital heart disease.

    Science.gov (United States)

    Wang, Jing; Liu, Zhen; Liu, Hongqian; Li, Nana; Li, Shengli; Chen, Xinlin; Lin, Yuan; Wang, He; Zhu, Jun; Liu, Shanling

    2013-01-01

    To validate multiplex ligation-dependent probe amplification (MLPA) with subtelomeric probe mixes as a tool for diagnosis of aneuploidy and unbalanced terminal chromosomal rearrangements in fetuses with congenital heart disease. A prospective study of 117 fetuses found to have structural heart defects by ultrasound at 17-40 weeks' gestation. MLPA with P036E and P070B probe mixes was performed and compared to traditional karyotyping by cell culture and to findings of quantitative fluorescence-polymerase chain reaction (QF-PCR). MLPA was able to define the fetal karyotype in 99% of cases whereas cell culture only defined the karyotype in 64% of cases. Consequently, the overall number of chromosomal abnormalities that were detected increased. The majority of these affected chromosomes, 21, 18, 13, X or Y, were also confirmed by QF-PCR. Two (5%) cases had atypical aneuploidy that was confirmed by MLPA but not by QF-PCR. In 4 cases, structural rearrangements or mosaicism were not detected by MLPA. Subtelomeric MLPA may be a valuable adjunct to QF-PCR and/or conventional cytogenetics for the investigation of chromosomal abnormalities in fetuses with congenital heart disease. Copyright © 2013 S. Karger AG, Basel.

  19. Touch-Based System for Beat-to-Beat Impedance Cardiogram Acquisition and Hemodynamic Parameters Estimation

    OpenAIRE

    Sopic, Dionisije; Murali, Srinivasan; Rincon Vallejos, Francisco Javier; Atienza Alonso, David

    2016-01-01

    Among all cardiovascular diseases, congestive heart failure (CHF) has a very high rate of hospitalization and mortality. In order to prevent hospitalization, there is a strong need to identify patients at risk of a CHF event by estimating a set of relevant hemodynamic parameters that will allow physicians to detect its early onset. Today, one of the most popular non-invasive methods to obtain these parameters is through the acquisition of electrocardiogram (ECG) and impedance cardiogram (IC...

  20. Gender- and age-related differences in heart rate dynamics: are women more complex than men?

    Science.gov (United States)

    Ryan, S. M.; Goldberger, A. L.; Pincus, S. M.; Mietus, J.; Lipsitz, L. A.

    1994-01-01

    OBJECTIVES. This study aimed to quantify the complex dynamics of beat-to-beat sinus rhythm heart rate fluctuations and to determine their differences as a function of gender and age. BACKGROUND. Recently, measures of heart rate variability and the nonlinear "complexity" of heart rate dynamics have been used as indicators of cardiovascular health. Because women have lower cardiovascular risk and greater longevity than men, we postulated that there are important gender-related differences in beat-to-beat heart rate dynamics. METHODS. We analyzed heart rate dynamics during 8-min segments of continuous electrocardiographic recording in healthy young (20 to 39 years old), middle-aged (40 to 64 years old) and elderly (65 to 90 years old) men (n = 40) and women (n = 27) while they performed spontaneous and metronomic (15 breaths/min) breathing. Relatively high (0.15 to 0.40 Hz) and low (0.01 to 0.15 Hz) frequency components of heart rate variability were computed using spectral analysis. The overall "complexity" of each heart rate time series was quantified by its approximate entropy, a measure of regularity derived from nonlinear dynamics ("chaos" theory). RESULTS. Mean heart rate did not differ between the age groups or genders. High frequency heart rate power and the high/low frequency power ratio decreased with age in both men and women (p cardiovascular disease risk and greater longevity in women requires further study.

  1. Quantification of fetal heart rate regularity using symbolic dynamics

    Science.gov (United States)

    van Leeuwen, P.; Cysarz, D.; Lange, S.; Geue, D.; Groenemeyer, D.

    2007-03-01

    Fetal heart rate complexity was examined on the basis of RR interval time series obtained in the second and third trimester of pregnancy. In each fetal RR interval time series, short term beat-to-beat heart rate changes were coded in 8bit binary sequences. Redundancies of the 28 different binary patterns were reduced by two different procedures. The complexity of these sequences was quantified using the approximate entropy (ApEn), resulting in discrete ApEn values which were used for classifying the sequences into 17 pattern sets. Also, the sequences were grouped into 20 pattern classes with respect to identity after rotation or inversion of the binary value. There was a specific, nonuniform distribution of the sequences in the pattern sets and this differed from the distribution found in surrogate data. In the course of gestation, the number of sequences increased in seven pattern sets, decreased in four and remained unchanged in six. Sequences that occurred less often over time, both regular and irregular, were characterized by patterns reflecting frequent beat-to-beat reversals in heart rate. They were also predominant in the surrogate data, suggesting that these patterns are associated with stochastic heart beat trains. Sequences that occurred more frequently over time were relatively rare in the surrogate data. Some of these sequences had a high degree of regularity and corresponded to prolonged heart rate accelerations or decelerations which may be associated with directed fetal activity or movement or baroreflex activity. Application of the pattern classes revealed that those sequences with a high degree of irregularity correspond to heart rate patterns resulting from complex physiological activity such as fetal breathing movements. The results suggest that the development of the autonomic nervous system and the emergence of fetal behavioral states lead to increases in not only irregular but also regular heart rate patterns. Using symbolic dynamics to

  2. Heart on a plate: histological and functional assessment of isolated adult zebrafish hearts maintained in culture.

    Directory of Open Access Journals (Sweden)

    Sebastian Pieperhoff

    Full Text Available The zebrafish is increasingly used for cardiovascular genetic and functional studies. We present a novel protocol to maintain and monitor whole isolated beating adult zebrafish hearts in culture for long-term experiments. Excised whole adult zebrafish hearts were transferred directly into culture dishes containing optimized L-15 Leibovitz growth medium and maintained for 5 days. Hearts were assessed daily using video-edge analysis of ventricle function using low power microscopy images. High-throughput histology techniques were used to assess changes in myocardial architecture and cell viability. Mean spontaneous Heart rate (HR, min(-1 declined significantly between day 0 and day 1 in culture (96.7 ± 19.5 to 45.2 ± 8.2 min-1, mean ± SD, p = 0.001, and thereafter declined more slowly to 27.6 ± 7.2 min(-1 on day 5. Ventricle wall motion amplitude (WMA did not change until day 4 in culture (day 0, 46.7 ± 13.0 µm vs day 4, 16.9 ± 1.9 µm, p = 0.08. Contraction velocity (CV declined between day 0 and day 3 (35.6 ± 14.8 vs 15.2 ± 5.3 µms(-1, respectively, p = 0.012 while relaxation velocity (RV declined quite rapidly (day 0, 72.5 ± 11.9 vs day 1, 29.5 ± 5.8 µms(-1, p = 0.03. HR and WMA responded consistently to isoproterenol from day 0 to day 5 in culture while CV and RV showed less consistent responses to beta-agonist. Cellular architecture and cross-striation pattern of cardiomyocytes remained unchanged up to day 3 in culture and thereafter showed significant deterioration with loss of striation pattern, pyknotic nuclei and cell swelling. Apoptotic markers within the myocardium became increasingly frequent by day 3 in culture. Whole adult zebrafish hearts can be maintained in culture-medium for up to 3 days. However, after day-3 there is significant deterioration in ventricle function and heart rate accompanied by significant histological changes consistent with cell death and loss of cardiomyocyte cell integrity. Further studies are

  3. Prolonged saltatory fetal heart rate pattern leading to newborn metabolic acidosis.

    Science.gov (United States)

    Nunes, I; Ayres-de-Campos, D; Kwee, A; Rosén, K G

    2014-01-01

    The saltatory pattern, characterized by wide and rapid oscillations of the fetal heart rate (FHR), remains a controversial entity. The authors sought to evaluate whether it could be associated with an adverse fetal outcome. The authors report a case series of four saltatory patterns occurring in the last 30 minutes before birth in association with cord artery metabolic acidosis, obtained from three large databases of internally acquired FHR tracings. The distinctive characteristics of this pattern were evaluated with the aid of a computer system. All cases were recorded in uneventful pregnancies, with normal birthweight singletons, born vaginally at term. The saltatory pattern lasted between 23 and 44 minutes, exhibited a mean oscillatory amplitude of 45.9 to 80.0 beats per minute (bpm) and a frequency between four and eight cycles per minute. A saltatory pattern exceeding 20 minutes can be associated with the occurrence of fetal metabolic acidosis.

  4. Using Complexity Metrics With R-R Intervals and BPM Heart Rate Measures

    Directory of Open Access Journals (Sweden)

    Sebastian eWallot

    2013-08-01

    Full Text Available Lately, growing attention in the health sciences has been paid to the dynamics of heart rate as indicator of impending failures and for prognoses. Likewise, in social and cognitive sciences, heart rate is increasingly employed as a measure of arousal, emotional engagement and as a marker of interpersonal coordination. However, there is no consensus about which measurements and analytical tools are most appropriate in mapping the temporal dynamics of heart rate and quite different metrics are reported in the literature. As complexity metrics of heart rate variability depend critically on variability of the data, different choices regarding the kind of measures can have a substantial impact on the results. In this article we compare linear and non-linear statistics on two prominent types of heart beat data, beat-to-beat intervals (R-R interval and beats-per-minute (BPM. As a proof-of-concept, we employ a simple rest-exercise-rest task and show that non-linear statistics – fractal (DFA and recurrence (RQA analyses – reveal information about heart beat activity above and beyond the simple level of heart rate. Non-linear statistics unveil sustained post-exercise effects on heart rate dynamics, but their power to do so critically depends on the type data that is employed: While R-R intervals are very susceptible to nonlinear analyses, the success of nonlinear methods for BPM data critically depends on their construction. Generally, ‘oversampled’ BPM time-series can be recommended as they retain most of the information about nonlinear aspects of heart beat dynamics.

  5. Using complexity metrics with R-R intervals and BPM heart rate measures.

    Science.gov (United States)

    Wallot, Sebastian; Fusaroli, Riccardo; Tylén, Kristian; Jegindø, Else-Marie

    2013-01-01

    Lately, growing attention in the health sciences has been paid to the dynamics of heart rate as indicator of impending failures and for prognoses. Likewise, in social and cognitive sciences, heart rate is increasingly employed as a measure of arousal, emotional engagement and as a marker of interpersonal coordination. However, there is no consensus about which measurements and analytical tools are most appropriate in mapping the temporal dynamics of heart rate and quite different metrics are reported in the literature. As complexity metrics of heart rate variability depend critically on variability of the data, different choices regarding the kind of measures can have a substantial impact on the results. In this article we compare linear and non-linear statistics on two prominent types of heart beat data, beat-to-beat intervals (R-R interval) and beats-per-min (BPM). As a proof-of-concept, we employ a simple rest-exercise-rest task and show that non-linear statistics-fractal (DFA) and recurrence (RQA) analyses-reveal information about heart beat activity above and beyond the simple level of heart rate. Non-linear statistics unveil sustained post-exercise effects on heart rate dynamics, but their power to do so critically depends on the type data that is employed: While R-R intervals are very susceptible to non-linear analyses, the success of non-linear methods for BPM data critically depends on their construction. Generally, "oversampled" BPM time-series can be recommended as they retain most of the information about non-linear aspects of heart beat dynamics.

  6. Recovery of spray paint traces from clothing by beating.

    Science.gov (United States)

    Olderiks, Maurice; Baiker, Martin; van Velzen, Jill; van der Weerd, Jaap

    2015-03-01

    Manual recovery of spray paints from textiles using a microscope, the routine method in many laboratories, is often laborious. Beating the clothing with a plastic rod, the routine method used for recovery of glass traces within the authors' laboratory, is proposed as an alternative. The efficiency of the method was evaluated by spray tests with fluorescent paint. In these tests, paint particles in the acquired debris samples, as well as those remaining on the textiles, were investigated. The results show that beating is an efficient way to recover and concentrate paint particles. A good efficiency for jeans fabric and rough knitwear is reported. The results appeared to be less satisfactory for smooth woven fabric. Application of the method in casework was effective for graffiti paints as well as for flaked car paint. © 2014 American Academy of Forensic Sciences.

  7. A neuro-fuzzy identification of ECG beats.

    Science.gov (United States)

    Chikh, Mohammed Amine; Ammar, Mohammed; Marouf, Radja

    2012-04-01

    This paper presents a fuzzy rule based classifier and its application to discriminate premature ventricular contraction (PVC) beats from normals. An Adaptive Neuro-Fuzzy Inference System (ANFIS) is applied to discover the fuzzy rules in order to determine the correct class of a given input beat. The main goal of our approach is to create an interpretable classifier that also provides an acceptable accuracy. The performance of the classifier is tested on MIT-BIH (Massachusetts Institute of Technology-Beth Israel Hospital) arrhythmia database. On the test set, we achieved an overall sensitivity and specificity of 97.92% and of 94.52% respectively. Experimental results show that the proposed approach is simple and effective in improving the interpretability of the fuzzy classifier while preserving the model performances at a satisfactory level.

  8. Implementing Mapping the Beat in the 8th Grade

    OpenAIRE

    Richardson, Ronald Craig

    2010-01-01

    This article looks at the woeful lack of geographic understanding exhibited by young people in the United States and proposes a solution. A series of workshops designed to supplement the eighth grade American history curriculum are described. Focusing on historical and ethnic music—the “soundtrack” of American history—the curriculum focuses on expanding student awareness of physical and cultural geography. The workshops build on the Mapping the Beat curriculum, originally developed ...

  9. Beating the Standard Quantum Limit with Four Entangled Photons

    OpenAIRE

    Nagata, Tomohisa; Okamoto, Ryo; O'Brien, Jeremy L.; Sasaki, Keiji; Takeuchi, Shigeki

    2007-01-01

    Precision measurements are important across all fields of science. In particular, optical phase measurements can be used to measure distance, position, displacement, acceleration and optical path length. Quantum entanglement enables higher precision than would otherwise be possible. We demonstrate an optical phase measurement with an entangled four photon interference visibility greater than the threshold to beat the standard quantum limit--the limit attainable without entanglement. These res...

  10. Beating the standard quantum limit with four-entangled photons.

    Science.gov (United States)

    Nagata, Tomohisa; Okamoto, Ryo; O'brien, Jeremy L; Sasaki, Keiji; Takeuchi, Shigeki

    2007-05-04

    Precision measurements are important across all fields of science. In particular, optical phase measurements can be used to measure distance, position, displacement, acceleration, and optical path length. Quantum entanglement enables higher precision than would otherwise be possible. We demonstrated an optical phase measurement with an entangled four-photon interference visibility greater than the threshold to beat the standard quantum limit-the limit attainable without entanglement. These results open the way for new high-precision measurement applications.

  11. Quantum Beats of Resonant Tunneling between Fractional Quantum Hall Edges

    Science.gov (United States)

    Maasilta, Ilari J.; Goldman, V. J.

    1997-03-01

    We report measurements of resonant tunneling between two fractional quantum Hall edges in a quantum antidot geometry (I. J. Maasilta and V. J. Goldman, to appear in Phys. Rev. B 55),(1997).. We observe beats in the conductance oscillations, whose evolution as a function of experimental parameters is discussed. Possible explanations in terms of different models (G. Kirczenow Phys. Rev. B 53), 15767 (1996), M. Geller et. al, preprint. are presented.

  12. Measuring of beat up force on weaving machines

    Directory of Open Access Journals (Sweden)

    Bílek Martin

    2017-01-01

    Full Text Available The textile material (warp is stressed cyclically at a relative high frequency during the weaving process. Therefore, the special measuring device for analysis of beat up force in the textile material during the weaving process, has been devised in the Weaving Laboratory of the TUL. This paper includes a description of this measuring device. The experimental part includes measurements results for various materials (PES and VS and various warp thread densities of the produced fabric.

  13. The role of the basal ganglia in beat perception: neuroimaging and neuropsychological investigations.

    Science.gov (United States)

    Grahn, Jessica A

    2009-07-01

    Perception of musical rhythms is culturally universal. Despite this special status, relatively little is known about the neurobiology of rhythm perception, particularly with respect to beat processing. Findings are presented here from a series of studies that have specifically examined the neural basis of beat perception, using functional magnetic resonance imaging (fMRI) and studying patients with Parkinson's disease. fMRI data indicate that novel beat-based sequences robustly activate the basal ganglia when compared to irregular, nonbeat sequences. Furthermore, although most healthy participants find it much easier to discriminate changes in beat-based sequences compared to irregular sequences, Parkinson's disease patients fail to show the same degree of benefit. Taken together, these data suggest that the basal ganglia are performing a crucial function in beat processing. The results of an additional fMRI study indicate that the role of the basal ganglia is strongly linked to internal generation of the beat. Basal ganglia activity is greater when participants listen to rhythms in which internal generation of the beat is required, as opposed to rhythms with strongly externally cued beats. Functional connectivity between part of the basal ganglia (the putamen) and cortical motor areas (premotor and supplementary motor areas) is also higher during perception of beat rhythms compared to nonbeat rhythms. Increased connectivity between cortical motor and auditory areas is found in those with musical training. The findings from these converging methods strongly implicate the basal ganglia in processing a regular beat, particularly when internal generation of the beat is required.

  14. The Effect of Binaural Beats on Visuospatial Working Memory and Cortical Connectivity.

    Science.gov (United States)

    Beauchene, Christine; Abaid, Nicole; Moran, Rosalyn; Diana, Rachel A; Leonessa, Alexander

    2016-01-01

    Binaural beats utilize a phenomenon that occurs within the cortex when two different frequencies are presented separately to each ear. This procedure produces a third phantom binaural beat, whose frequency is equal to the difference of the two presented tones and which can be manipulated for non-invasive brain stimulation. The effects of binaural beats on working memory, the system in control of temporary retention and online organization of thoughts for successful goal directed behavior, have not been well studied. Furthermore, no studies have evaluated the effects of binaural beats on brain connectivity during working memory tasks. In this study, we determined the effects of different acoustic stimulation conditions on participant response accuracy and cortical network topology, as measured by EEG recordings, during a visuospatial working memory task. Three acoustic stimulation control conditions and three binaural beat stimulation conditions were used: None, Pure Tone, Classical Music, 5Hz binaural beats, 10Hz binaural beats, and 15Hz binaural beats. We found that listening to 15Hz binaural beats during a visuospatial working memory task not only increased the response accuracy, but also modified the strengths of the cortical networks during the task. The three auditory control conditions and the 5Hz and 10Hz binaural beats all decreased accuracy. Based on graphical network analyses, the cortical activity during 15Hz binaural beats produced networks characteristic of high information transfer with consistent connection strengths throughout the visuospatial working memory task.

  15. The Effect of Binaural Beats on Visuospatial Working Memory and Cortical Connectivity.

    Directory of Open Access Journals (Sweden)

    Christine Beauchene

    Full Text Available Binaural beats utilize a phenomenon that occurs within the cortex when two different frequencies are presented separately to each ear. This procedure produces a third phantom binaural beat, whose frequency is equal to the difference of the two presented tones and which can be manipulated for non-invasive brain stimulation. The effects of binaural beats on working memory, the system in control of temporary retention and online organization of thoughts for successful goal directed behavior, have not been well studied. Furthermore, no studies have evaluated the effects of binaural beats on brain connectivity during working memory tasks. In this study, we determined the effects of different acoustic stimulation conditions on participant response accuracy and cortical network topology, as measured by EEG recordings, during a visuospatial working memory task. Three acoustic stimulation control conditions and three binaural beat stimulation conditions were used: None, Pure Tone, Classical Music, 5Hz binaural beats, 10Hz binaural beats, and 15Hz binaural beats. We found that listening to 15Hz binaural beats during a visuospatial working memory task not only increased the response accuracy, but also modified the strengths of the cortical networks during the task. The three auditory control conditions and the 5Hz and 10Hz binaural beats all decreased accuracy. Based on graphical network analyses, the cortical activity during 15Hz binaural beats produced networks characteristic of high information transfer with consistent connection strengths throughout the visuospatial working memory task.

  16. Ultrafast quantum beats of anisotropic excitons in atomically thin ReS2.

    Science.gov (United States)

    Sim, Sangwan; Lee, Doeon; Trifonov, Artur V; Kim, Taeyoung; Cha, Soonyoung; Sung, Ji Ho; Cho, Sungjun; Shim, Wooyoung; Jo, Moon-Ho; Choi, Hyunyong

    2018-01-24

    Quantum beats, periodic oscillations arising from coherent superposition states, have enabled exploration of novel coherent phenomena. Originating from strong Coulomb interactions and reduced dielectric screening, two-dimensional transition metal dichalcogenides exhibit strongly bound excitons either in a single structure or hetero-counterpart; however, quantum coherence between excitons is barely known to date. Here we observe exciton quantum beats in atomically thin ReS2 and further modulate the intensity of the quantum beats signal. Surprisingly, linearly polarized excitons behave like a coherently coupled three-level system exhibiting quantum beats, even though they exhibit anisotropic exciton orientations and optical selection rules. Theoretical studies are also provided to clarify that the observed quantum beats originate from pure quantum coherence, not from classical interference. Furthermore, we modulate on/off quantum beats only by laser polarization. This work provides an ideal laboratory toward polarization-controlled exciton quantum beats in two-dimensional materials.

  17. Auditory beat stimulation and its effects on cognition and mood states

    Directory of Open Access Journals (Sweden)

    Leila eChaieb

    2015-05-01

    Full Text Available Auditory beat stimulation may be a promising new tool for the manipulation of cognitive processes and the modulation of mood-states. Here we aim to review the literature examining the most current applications of auditory beat stimulation and its targets. We give a brief overview of research on auditory steady-state responses and its relationship to auditory beat stimulation. We have summarized relevant studies investigating the neurophysiological changes related to auditory beat stimulation and how they impact upon the design of appropriate stimulation protocols. Focusing on binaural beat stimulation, we then discuss the role of monaural and binaural beat frequencies in cognition and mood-states, in addition to their efficacy in targeting disease symptoms. We aim to highlight important points concerning stimulation parameters and try to address why there are often contradictory findings with regard to the outcomes of auditory beat stimulation.

  18. Effectiveness of binaural beats in reducing preoperative dental anxiety.

    Science.gov (United States)

    Isik, B K; Esen, A; Büyükerkmen, B; Kilinç, A; Menziletoglu, D

    2017-07-01

    Binaural beats are an auditory illusion perceived when two different pure-tone sine waves are presented one to each ear at a steady intensity and frequency. We evaluated their effectiveness in reducing preoperative anxiety in dentistry. Sixty patients (30 in each group) who were to have impacted third molars removed were studied (experimental group: 20 women and 10 men, mean (range) age 24 (18-35) years, and control group: 22 women and 8 men, mean (range) age 28 (15-47) years). All patients were fully informed about the operation preoperatively, and their anxiety recorded on a visual analogue scale (VAS). The local anaesthetic was given and the patients waited for 10minutes, during which those in the experimental group were asked to listen to binaural beats through stereo earphones (200Hz for the left ear and 209.3Hz for the right ear). No special treatment was given to the control group. In both groups anxiety was then recorded again, and the tooth removed in the usual way. The paired t test and t test were used to assess the significance of differences between groups. The degree of anxiety in the control group was unchanged after the second measurement (p=0.625), while that in the experimental group showed a significant reduction in anxiety (p=0.001). We conclude that binaural beats may be useful in reducing preoperative anxiety in dentistry. Copyright © 2017 The British Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.

  19. Moving to the beat and singing are linked in humans

    Directory of Open Access Journals (Sweden)

    Simone eDalla Bella

    2015-12-01

    Full Text Available The abilities to sing and to move to the beat of a rhythmic auditory stimulus emerge early during development, and both engage perceptual, motor, and sensorimotor processes. These similarities between singing and synchronization to a beat may be rooted in biology. Patel (2008 has suggested that motor synchronization to auditory rhythms may have emerged during evolution as a byproduct of selection for vocal learning (vocal learning and synchronization hypothesis. This view predicts a strong link between vocal performance and synchronization skills in humans. Here we tested this prediction by asking occasional singers to tap along with auditory pulse trains and to imitate familiar melodies. Both vocal imitation and synchronization skills were measured in terms of accuracy and precision or consistency. Accurate and precise singers tapped more in the vicinity of the pacing stimuli (i.e., they were more accurate than inaccurate and imprecise singers. Moreover, accurate singers were more consistent when tapping to the beat. These differences cannot be ascribed to basic motor skills or to motivational factors. Individual differences in terms of singing proficiency and synchronization skills may reflect the variability of a shared sensorimotor translation mechanism.

  20. Evolution of Action Potential Alternans in Rabbit Heart during Acute Regional Ischemia

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    Irma Martišienė

    2015-01-01

    Full Text Available This study investigates the development of the spatiotemporal pattern of action potential alternans during acute regional ischemia. Experiments were carried out in isolated Langendorff-perfused rabbit heart using a combination of optical mapping and microelectrode recordings. The alternans pattern significantly changed over time and had a biphasic character reaching maximum at 6–9 min after occlusion. Phase I (3–11 minutes of ischemia is characterized by rapid increase in the alternans magnitude and expansion of the alternans territory. Phase I is followed by gradual decline of alternans (Phase II in both magnitude and territory. During both phases we observed significant beat-to-beat variations of the optical action potential amplitude (OAPA alternans. Simultaneous microelectrode recordings from subepicardial and subendocardial layers showed that OAPA alternans coincided with intramural 2 : 1 conduction blocks. Our findings are consistent with the modeling studies predicting that during acute regional ischemia alternans can be driven by 2 : 1 conduction blocks in the ischemic region.

  1. Heart Disease

    Science.gov (United States)

    ... type of heart disease you have. Symptoms of heart disease in your blood vessels (atherosclerotic disease) Cardiovascular disease ... can sometimes be found early with regular evaluations. Heart disease symptoms caused by abnormal heartbeats (heart arrhythmias) A ...

  2. Discrete Scale Invariance in the Cascade Heart Rate Variability Of Healthy Humans

    OpenAIRE

    Lin, Der Chyan

    2004-01-01

    Evidence of discrete scale invariance (DSI) in daytime healthy heart rate variability (HRV) is presented based on the log-periodic power law scaling of the heart beat interval increment. Our analysis suggests multiple DSI groups and a dynamic cascading process. A cascade model is presented to simulate such a property.

  3. Study on the Relationship among Parents' Cognition on China Anti-Domestic Violence, Attitude of Beating Children and Frequency of Beating Children

    Science.gov (United States)

    Song, Shi

    2018-01-01

    This research aims at analyzing the correlation between parents' awareness of anti-domestic violence in China, attitude and frequency of beating children. According to the literature analysis, this paper sets children's parents' anti-domestic violence cognition and attitude of beating children as independent variable, and the frequency of beating…

  4. Mitral valve m-mode echo in complete heart block with atrial tachycardia

    Directory of Open Access Journals (Sweden)

    Kalathingathodika Sajeer

    2013-01-01

    Full Text Available We report a 48-year-old man who presented with history of syncope. Electrocardiogram on admission showed infrahisian complete heart block with a ventricular rate of 36 beats per min with wide QRS junctional escape and atrial rate was 188 beats per min. Transthoracic echocardiogram showed fine vibratory movement of both mitral leaflet tips. M-mode evaluation of mitral leaflets showed multiple ′a′ waves corresponding to atrial tachycardia rate.

  5. Beat-to-beat analysis of the relation between RT and RR intervals in newborns.

    Science.gov (United States)

    Pladys, Patrick; Senhadji, Lotfi; Blanche, Pierre Maison; Beuchée, Alain; Bétrémieux, Pierre; Carré, François

    2003-01-01

    To evaluate the dynamic RT (QRS apex-end of T wave) rate dependence in newborns. A Digital Holter ECG was acquired on day 15 in nine full-term and eight preterm infants. Ten-minute periods were recorded during wakefulness and sleep. The accuracy of fit with RT-RR pairs was individually assessed by 14 regression formulas (r coefficient, Akaike score, residual analysis). The medians of RT and Bazett's RT correction were calculated for each 10 milliseconds of RR. The mean RR and RT were 429+/-51 and 263+/-18 milliseconds. None of the prediction formulas were sufficiently accurate to describe RT over the whole range of RR (r<0.56). The Bazett correction produced differences of more than 50 milliseconds at different RR. Prematurity, sleep state and heart rate variability did not influence RT-RR relation. None of the parametric formulas were found to be accurate in describing RT rate dependence in newborns.

  6. Neural Entrainment and Sensorimotor Synchronization to the Beat in Children with Developmental Dyslexia: An EEG Study

    Directory of Open Access Journals (Sweden)

    Lincoln J. Colling

    2017-07-01

    Full Text Available Tapping in time to a metronome beat (hereafter beat synchronization shows considerable variability in child populations, and individual differences in beat synchronization are reliably related to reading development. Children with developmental dyslexia show impairments in beat synchronization. These impairments may reflect deficiencies in auditory perception of the beat which in turn affect auditory-motor mapping, or may reflect an independent motor deficit. Here, we used a new methodology in EEG based on measuring beat-related steady-state evoked potentials (SS-EPs, Nozaradan et al., 2015 in an attempt to disentangle neural sensory and motor contributions to behavioral beat synchronization in children with dyslexia. Children tapped with both their left and right hands to every second beat of a metronome pulse delivered at 2.4 Hz, or listened passively to the beat. Analyses of preferred phase in EEG showed that the children with dyslexia had a significantly different preferred phase compared to control children in all conditions. Regarding SS-EPs, the groups differed significantly for the passive Auditory listening condition at 2.4 Hz, and showed a trend toward a difference in the Right hand tapping condition at 3.6 Hz (sensorimotor integration measure. The data suggest that neural rhythmic entrainment is atypical in children with dyslexia for both an auditory beat and during sensorimotor coupling (tapping. The data are relevant to a growing literature suggesting that rhythm-based interventions may help language processing in children with developmental disorders of language learning.

  7. Loss of lag-response curvilinearity of indices of heart rate variability in congestive heart failure

    Science.gov (United States)

    Thakre, Tushar P; Smith, Michael L

    2006-01-01

    Background Heart rate variability (HRV) is known to be impaired in patients with congestive heart failure (CHF). Time-domain analysis of ECG signals traditionally relies heavily on linear indices of an essentially non-linear phenomenon. Poincaré plots are commonly used to study non-linear behavior of physiologic signals. Lagged Poincaré plots incorporate autocovariance information and analysis of Poincaré plots for various lags can provide interesting insights into the autonomic control of the heart. Methods Using Poincaré plot analysis, we assessed whether the relation of the lag between heart beats and HRV is altered in CHF. We studied the influence of lag on estimates of Poincaré plot indices for various lengths of beat sequence in a public domain data set (PhysioNet) of 29 subjects with CHF and 54 subjects with normal sinus rhythm. Results A curvilinear association was observed between lag and Poincaré plot indices (SD1, SD2, SDLD and SD1/SD2 ratio) in normal subjects even for a small sequence of 50 beats (p value for quadratic term 3 × 10-5, 0.002, 3.5 × 10-5 and 0.0003, respectively). This curvilinearity was lost in patients with CHF even after exploring sequences up to 50,000 beats (p values for quadratic term > 0.5). Conclusion Since lagged Poincaré plots incorporate autocovariance information, these analyses provide insights into the autonomic control of heart rate that is influenced by the non-linearity of the signal. The differences in lag-response in CHF patients and normal subjects exist even in the face of the treatment received by the CHF patients. PMID:16768800

  8. Loss of lag-response curvilinearity of indices of heart rate variability in congestive heart failure

    Directory of Open Access Journals (Sweden)

    Smith Michael L

    2006-06-01

    Full Text Available Abstract Background Heart rate variability (HRV is known to be impaired in patients with congestive heart failure (CHF. Time-domain analysis of ECG signals traditionally relies heavily on linear indices of an essentially non-linear phenomenon. Poincaré plots are commonly used to study non-linear behavior of physiologic signals. Lagged Poincaré plots incorporate autocovariance information and analysis of Poincaré plots for various lags can provide interesting insights into the autonomic control of the heart. Methods Using Poincaré plot analysis, we assessed whether the relation of the lag between heart beats and HRV is altered in CHF. We studied the influence of lag on estimates of Poincaré plot indices for various lengths of beat sequence in a public domain data set (PhysioNet of 29 subjects with CHF and 54 subjects with normal sinus rhythm. Results A curvilinear association was observed between lag and Poincaré plot indices (SD1, SD2, SDLD and SD1/SD2 ratio in normal subjects even for a small sequence of 50 beats (p value for quadratic term 3 × 10-5, 0.002, 3.5 × 10-5 and 0.0003, respectively. This curvilinearity was lost in patients with CHF even after exploring sequences up to 50,000 beats (p values for quadratic term > 0.5. Conclusion Since lagged Poincaré plots incorporate autocovariance information, these analyses provide insights into the autonomic control of heart rate that is influenced by the non-linearity of the signal. The differences in lag-response in CHF patients and normal subjects exist even in the face of the treatment received by the CHF patients.

  9. Rapid emergence of atherosclerosis in Asia: a systematic review of coronary atherosclerotic heart disease epidemiology and implications for prevention and control strategies.

    Science.gov (United States)

    Wong, Martin C S; Zhang, De Xing; Wang, Harry H X

    2015-08-01

    There is a global epidemic of coronary heart disease (CHD) caused by atherosclerosis. We discussed its emergence, underlying reasons, and implications for prevention and control strategies in Asia. Most countries in Asia are experiencing the challenges from CHD, with the mortality rate varying from 103 to 366 per 100 000 adult populations, reported by recently published studies. Raised population cholesterol levels played a pivotal role. Men, older adults, and those with dyslipidemia, hypertension, and diabetes were high-risk individuals. During the past decade, there was a marked rising trend of atherosclerosis-related burden particularly in Eastern Asia where an alarming increase of 117.2 and 115.3% of total deaths and disability adjusted life-years, respectively, were observed. The rise of CHD could be attributed to unhealthy lifestyles, clinical-risk factors, psychosocial factors, and public health transitions. Ageing, urbanization, and increase in prosperity may serve as underlying key drivers. The burden of CHD is substantial, whereas contributors are multifactorial. This grand challenge should be a top priority for injecting healthcare resources. The formulation of public health measures will need to adopt an integrated and life-course approach, based on the need and risks of different population subgroups in Asia.

  10. Shock from heart device often triggers further health care needs

    Science.gov (United States)

    ... heart device often triggers further health care needs American Heart Association Rapid Access Journal Report February 14, 2017 Categories: ... published in Circulation: Cardiovascular Quality and Outcomes , an American Heart Association journal. ICDs save people from sudden cardiac death ...

  11. a Beat Perioid Observation of the Asynchronous Polar by Cam.

    Science.gov (United States)

    Rainger, Jonathan

    We propose to observe the hard X-ray bright asynchronous polar BY Cam throughout its beat cycle in order to investigate the changes in the magnetic capture of the accretion stream as the secondary star changes in azimuth with respect to the white dwarf. Regular snap-shots of the light curve will reveal the order behind the chaos. Previous observations have been taken in 3 days or less, our monitoring plan over 21 days offers the only real hope of understanding these difficult systems.

  12. Wife beating amongst Africans as a challenge to pastoral care

    Directory of Open Access Journals (Sweden)

    Magezi E. Baloyi

    2013-11-01

    Full Text Available Traditional African people are known for respecting their marriage. Even though marriage is so highly regarded, it is astonishing to realise that wife beating has become an extremely common practice amongst them. It therefore becomes an important research question to ask about the extent to which deeply-seated traditional customs regarding wife beating as a form of stamping down authority and of trying to keep the household in order, will have to be confronted with what is deemed to be good practice from the perspective of the law, community and pastoral caregivers. There are women who live with scars on their faces and bodies, having been beaten by their husbands. Although there are many forms of abuse towards women in family situations, this article aims particularly to focus on wife beating that is practiced for traditional as well as other related reasons. This research will involve itself with establishing whether the reasons for wife beating are part of the traditional system for keeping the household in order and interrogate both legal and pastoral interventions that attempt to eliminate or avoid such behaviour. Tradisionele Afrikane is nog altyd daarvoor bekend dat hulle die instelling van die huwelik respekteer. Verbasend genoeg is vroueslanery egter ’n ou gevestigde gebruik wat vandag algemeen onder Afrikane voorkom. Die mate waartoe diepgewortelde gebruike soos vroueslanery as ’n manier om gesag af te dwing en orde in die huis te handhaaf, gekonfronteer sal moet word met wat as goeie praktyk beskou word vanuit die gesigspunt van die reg, die gemeenskap en pastorale versorgers, is dus ’n belangrike navorsingsvraag. Baie vroue dra fisiese en emosionele littekens wat deur hulle eggenote veroorsaak is. Alhoewel daar baie vorme van vrouemishandeling in familiesituasies voorkom, fokus hierdie artikel veral op vroueslanery wat om tradisionele en verwante redes beoefen word. Hierdie navorsing probeer vasstel of die redes vir

  13. The beat frequency model for QPOs. [Quasi-Periodic-Oscillations

    Science.gov (United States)

    Shaham, Jacob

    1987-01-01

    The quasi-periodic oscillation (QPO) phenomenon has come to pose increasingly complex problems as sources have been discovered; these currently number 12, of which at least seven are X-ray binaries. The beat-frequency model (BFM), originally devised to characterize the first and simplest of the QPOs, GX5-1, is presently discussed with a view to its assumptions and applicability to other QPOs. The most important problem with the BFM is identified as the assumption that the neutron star involved rotates at an angular frequency of the order, in the case of GX5-1, of 10 msec.

  14. Ginsenoside Re prevents angiotensin II-induced gap-junction remodeling by activation of PPARγ in isolated beating rat atria.

    Science.gov (United States)

    Zhang, Bo; Cui, Xun; Jin, Hong-Hua; Hong, Lan; Liu, Xia; Li, Xiang; Zhang, Qing-Gao; Liu, Li-Ping

    2017-12-01

    Ginsenoside Re (G-Re), a major ginsenoside in ginseng, has many beneficial pharmacological effects on negative cardiac contractility, electromechanical alternans, antiarrhythmia, angiogenic regeneration and cardiac electrophysiological function. However, effects of G-Re on gap-junction remodeling are unclear. Therefore, this study aimed to investigate the effect of G-Re on angiotensin II (Ang II)-induced downregulation of connexin-40 (CX40) and -43 (CX43) in beating rat left atria. In this study, the isolated perfused beating rat atrial model was used and atrial gap-junction remodeling was induced by Ang II. In vivo hemodynamic experiments were analyzed with a biological recorder. Changes in protein expression were analyzed by western blot. G-Re attenuated Ang II-induced abnormal changes in heart rate, MAP, LVESP, LVEDP, +dp/dt max, -dp/dt min, P wave amplitude, P-R interval and P wave length. This indicated a dose-dependent preventive role against Ang II-induced hyper hemodynamics in rats. Atrial activities of p38 mitogen-activated protein kinase (MAPK), nuclear factor kappa-B (NF-κB) and activator protein 1 (AP-1) were significantly increased by Ang II, as was expression of atrial collagen I and matrix metalloproteinase 2 (MMP2). Atrial CX40 and CX43 expression was downregulated by Ang II. These Ang II-induced atrial effects were blocked by G-Re, as well as rosiglitazone, an agonist of peroxisome proliferator-activated receptor γ (PPARγ), in a dose-dependent manner. However, this inhibition was abolished by the PPARγ inhibitor GW9662. G-Re may suppress Ang II-induced downregulation of CX40 and CX43, by activating PPARγ signaling, in isolated perfused beating rat atria. Copyright © 2017. Published by Elsevier Inc.

  15. Beat map drawing method for large oriental bell based on operational deflection shape method

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Joong Hyeok; Kim, Seock Hyun [Dept. of Advanced Mechanical Engineering, Kangwon National University, Chuncheon (Korea, Republic of); Park, In Seok [TB Tires Development 1 Team, R and D Center, Kumho Tire, Yongin (Korea, Republic of)

    2016-10-15

    Oriental bells produce a peculiar sound in the form of beats, which are periodic repetitions of strong and weak sounds. A beating sound with a proper period gives the illusion of the bell being alive and breathing. To produce a good beating sound, appropriate modal parameters are required for beat tuning after casting the bell. Conventionally, modal parameters were extracted using frequency response functions of the excitation and response signals. However, a large oriental bell is usually struck by a heavy wooden hammer and hence, only the response signal can be measured. In this study, we extract the modal parameters using the response signal only and employ the data to predict the beat properties of the bell sound. Finally, the validity of the predicted beat properties is experimentally verified for a large oriental bell.

  16. Dynamic curvature regulation accounts for the symmetric and asymmetric beats of Chlamydomonas flagella

    CERN Document Server

    Sartori, Pablo; Scholich, Andre; Jülicher, Frank; Howard, Jonathon

    2015-01-01

    Axonemal dyneins are the molecular motors responsible for the beating of cilia and flagella. These motors generate sliding forces between adjacent microtubule doublets within the axoneme, the motile cytoskeletal structure inside the flagellum. To create regular, oscillatory beating patterns, the activities of the axonemal dyneins must be coordinated both spatially and temporally. It is thought that coordination is mediated by stresses or strains that build up within the moving axoneme, but it is not known which components of stress or strain are involved, nor how they feed back on the dyneins. To answer this question, we used isolated, reactivate axonemes of the unicellular alga Chlamydomonas as a model system. We derived a theory for beat regulation in a two-dimensional model of the axoneme. We then tested the theory by measuring the beat waveforms of wild type axonemes, which have asymmetric beats, and mutant axonemes, in which the beat is nearly symmetric, using high-precision spatial and temporal imaging....

  17. Individual differences in beat perception affect gait responses to low- and high-groove music.

    Directory of Open Access Journals (Sweden)

    Li-Ann eLeow

    2014-10-01

    Full Text Available Slowed gait in Parkinson’s disease (PD patients can be improved when patients synchronize footsteps to isochronous metronome cues, but limited retention of such improvements suggest that permanent cueing regimes are needed for long-term improvements. If so, music might make permanent cueing regimes more pleasant, improving adherence; however, music cueing requires patients to synchronize movements to the beat, which might be difficult for PD patients who tend to show weak beat perception. One solution may be to use high groove music, which has high beat salience that may facilitate synchronization, and affective properties which may improve motivation to move. As a first step in understanding how beat perception affects gait in complex neurological disorders, we examined how beat perception ability affected gait in neurotypical adults. Synchronization performance and gait parameters were assessed as healthy young adults with strong or weak beat perception synchronized to low groove music, high groove music, and metronome cues. High groove music was predicted to elicit better synchronization than low groove music, due to its higher beat salience. Two musical tempi, or rates, were used: (1 preferred tempo: beat rate matched to preferred step rate and (2 faster tempo: beat rate adjusted to 22.5% faster than preferred step rate. For both strong and weak beat-perceivers, synchronization performance was best with metronome cues, followed by high groove music, and worst with low groove music. In addition, high groove music elicited longer and faster steps than low groove music, both at preferred tempo and at faster tempo. Low groove music was particularly detrimental to gait in weak beat-perceivers, who showed slower and shorter steps compared to uncued walking. The findings show that individual differences in beat perception affect gait when synchronizing footsteps to music, and have implications for using music in gait rehabilitation.

  18. Matrix Organisation : The design of cross-beat teamwork in newsrooms

    OpenAIRE

    Grubenmann, Stephanie

    2016-01-01

    Confronted by increased internal and external complexity, traditional forms of newswork have reached their limits. Journalistic start-ups, such as Quartz and NZZ.at, form emerging editorial teams around "obsessions" or "phenomena" to gain cross-beat perspectives of complex issues such as climate change, the financial crisis or the refugee crisis. Legacy media experimenting with cross-beat newswork see themselves confronted by challenges arising predominantly from beat structures. Consequently...

  19. Individual differences in beat perception affect gait responses to low- and high-groove music.

    Science.gov (United States)

    Leow, Li-Ann; Parrott, Taylor; Grahn, Jessica A

    2014-01-01

    Slowed gait in patients with Parkinson's disease (PD) can be improved when patients synchronize footsteps to isochronous metronome cues, but limited retention of such improvements suggest that permanent cueing regimes are needed for long-term improvements. If so, music might make permanent cueing regimes more pleasant, improving adherence; however, music cueing requires patients to synchronize movements to the "beat," which might be difficult for patients with PD who tend to show weak beat perception. One solution may be to use high-groove music, which has high beat salience that may facilitate synchronization, and affective properties, which may improve motivation to move. As a first step to understanding how beat perception affects gait in complex neurological disorders, we examined how beat perception ability affected gait in neurotypical adults. Synchronization performance and gait parameters were assessed as healthy young adults with strong or weak beat perception synchronized to low-groove music, high-groove music, and metronome cues. High-groove music was predicted to elicit better synchronization than low-groove music, due to its higher beat salience. Two musical tempi, or rates, were used: (1) preferred tempo: beat rate matched to preferred step rate and (2) faster tempo: beat rate adjusted to 22.5% faster than preferred step rate. For both strong and weak beat-perceivers, synchronization performance was best with metronome cues, followed by high-groove music, and worst with low-groove music. In addition, high-groove music elicited longer and faster steps than low-groove music, both at preferred tempo and at faster tempo. Low-groove music was particularly detrimental to gait in weak beat-perceivers, who showed slower and shorter steps compared to uncued walking. The findings show that individual differences in beat perception affect gait when synchronizing footsteps to music, and have implications for using music in gait rehabilitation.

  20. Heart Disease Risk Factors

    Science.gov (United States)

    ... t Miss a Beat National Women and Girls HIV/AIDS Awareness Day National Women's Health Week Supporting Nursing Moms ... t Miss a Beat National Women and Girls HIV/AIDS Awareness Day National Women's Health Week Supporting Nursing Moms ...

  1. Heart Failure

    Science.gov (United States)

    Heart failure is a condition in which the heart can't pump enough blood to meet the body's needs. Heart failure does not mean that your heart has stopped ... and shortness of breath Common causes of heart failure are coronary artery disease, high blood pressure and ...

  2. Heart-pulse Biofeedback in Playful Exercise using a Wearable device and Modular Interactive Tiles

    DEFF Research Database (Denmark)

    Shimokakimoto, Tomoya; Lund, Henrik Hautop; Suzuki, Kenji

    2014-01-01

    interactive tiles. The system consists of a wearable device that measures heart-pulse via ear-mounted sensor, and modular interactive tiles which are used for physical rehabilitation exercise through playing a game. The wearable devise enables detection of heart pulse in real-time and therefore provides heart...... beat rate during playful activities, even if the heart pulse wave have motion artifacts. The tiles are designed to build flexible structures and to provide immediate feedback based on the users’ physical interaction with the tiles. We combine the two systems to provide users with heart pulse...... biofeedback in playful exercise. We show that using the developed system it is possible for the users to regulate the exercise intensity on their own with biofeedback, and also possible to analyze exercise activity using number of steps on the tiles and heart beat rate....

  3. Transplantation of Hearts Donated after Circulatory Death

    Directory of Open Access Journals (Sweden)

    Christopher W. White

    2018-02-01

    Full Text Available Cardiac transplantation has become limited by a critical shortage of suitable organs from brain-dead donors. Reports describing the successful clinical transplantation of hearts donated after circulatory death (DCD have recently emerged. Hearts from DCD donors suffer significant ischemic injury prior to organ procurement; therefore, the traditional approach to the transplantation of hearts from brain-dead donors is not applicable to the DCD context. Advances in our understanding of ischemic post-conditioning have facilitated the development of DCD heart resuscitation strategies that can be used to minimize ischemia-reperfusion injury at the time of organ procurement. The availability of a clinically approved ex situ heart perfusion device now allows DCD heart preservation in a normothermic beating state and minimizes exposure to incremental cold ischemia. This technology also facilitates assessments of organ viability to be undertaken prior to transplantation, thereby minimizing the risk of primary graft dysfunction. The application of a tailored approach to DCD heart transplantation that focuses on organ resuscitation at the time of procurement, ex situ preservation, and pre-transplant assessments of organ viability has facilitated the successful clinical application of DCD heart transplantation. The transplantation of hearts from DCD donors is now a clinical reality. Investigating ways to optimize the resuscitation, preservation, evaluation, and long-term outcomes is vital to ensure a broader application of DCD heart transplantation in the future.

  4. Enhanced Timing Abilities in Percussionists Generalize to Rhythms Without a Musical Beat

    Directory of Open Access Journals (Sweden)

    Daniel J Cameron

    2014-12-01

    Full Text Available The ability to entrain movements to music is arguably universal, but it is unclear how specialized training may influence this. Previous research suggests that percussionists have superior temporal precision in perception and production tasks. Such superiority may be limited to temporal sequences that resemble real music or, alternatively, may generalize to musically implausible sequences. To test this, percussionists and nonpercussionists completed two tasks that used rhythmic sequences varying in musical plausibility. In the beat tapping task, participants tapped with the beat of a rhythmic sequence over 3 stages: finding the beat (as an initial sequence played, continuation of the beat (as a second sequence was introduced and played simultaneously, and switching to a second beat (the initial sequence finished, leaving only the second. The metres of the two sequences were either congruent or incongruent, as were their tempi (minimum inter-onset intervals. In the rhythm reproduction task, participants reproduced rhythms of four types, ranging from high to low musical plausibility: Metric simple rhythms induced a strong sense of the beat, metric complex rhythms induced a weaker sense of the beat, nonmetric rhythms had no beat, and jittered nonmetric rhythms also had no beat as well as low temporal predictability. For both tasks, percussionists performed more accurately than nonpercussionists. In addition, both groups were better with musically plausible than implausible conditions. Overall, the percussionists’ superior abilities to entrain to, and reproduce, rhythms generalized to musically implausible sequences.

  5. Enhanced timing abilities in percussionists generalize to rhythms without a musical beat.

    Science.gov (United States)

    Cameron, Daniel J; Grahn, Jessica A

    2014-01-01

    The ability to entrain movements to music is arguably universal, but it is unclear how specialized training may influence this. Previous research suggests that percussionists have superior temporal precision in perception and production tasks. Such superiority may be limited to temporal sequences that resemble real music or, alternatively, may generalize to musically implausible sequences. To test this, percussionists and nonpercussionists completed two tasks that used rhythmic sequences varying in musical plausibility. In the beat tapping task, participants tapped with the beat of a rhythmic sequence over 3 stages: finding the beat (as an initial sequence played), continuation of the beat (as a second sequence was introduced and played simultaneously), and switching to a second beat (the initial sequence finished, leaving only the second). The meters of the two sequences were either congruent or incongruent, as were their tempi (minimum inter-onset intervals). In the rhythm reproduction task, participants reproduced rhythms of four types, ranging from high to low musical plausibility: Metric simple rhythms induced a strong sense of the beat, metric complex rhythms induced a weaker sense of the beat, nonmetric rhythms had no beat, and jittered nonmetric rhythms also had no beat as well as low temporal predictability. For both tasks, percussionists performed more accurately than nonpercussionists. In addition, both groups were better with musically plausible than implausible conditions. Overall, the percussionists' superior abilities to entrain to, and reproduce, rhythms generalized to musically implausible sequences.

  6. Human cortical responses to slow and fast binaural beats reveal multiple mechanisms of binaural hearing

    National Research Council Canada - National Science Library

    Ross, Bernhard; Miyazaki, Takahiro; Thompson, Jessica; Jamali, Shahab; Fujioka, Takako

    2014-01-01

    .... To examine the neural representations underlying these different perceptions, we recorded neuromagnetic cortical responses while participants listened to binaural beats at a continuously varying rate...

  7. Age-period-cohort projections of ischaemic heart disease mortality by socio-economic position in a rapidly transitioning Chinese population.

    Directory of Open Access Journals (Sweden)

    Irene O L Wong

    Full Text Available BACKGROUND: With economic development and population aging, ischaemic heart disease (IHD is becoming a leading cause of mortality with widening inequalities in China. To forewarn the trends in China we projected IHD trends in the most economically developed part of China, i.e., Hong Kong. METHODS: Based on sex-specific IHD mortality rates from 1976 to 2005, we projected mortality rates by neighborhood-level socio-economic position (i.e., low- or high-income groups to 2020 in Hong Kong using Poisson age-period-cohort models with autoregressive priors. RESULTS: In the low-income group, age-standardized IHD mortality rates among women declined from 33.3 deaths in 1976-1980 to 19.7 per 100,000 in 2016-2020 (from 55.5 deaths to 34.2 per 100,000 among men. The rates in the high-income group were initially higher in both sexes, particularly among men, but this had reversed by the end of the study periods. The rates declined faster for the high-income group than for the low-income group in both sexes. The rates were projected to decline faster in the high-income group, such that by the end of the projection period the high-income group would have lower IHD mortality rates, particularly for women. Birth cohort effects varied with sex, with a marked upturn in IHD mortality around 1945, i.e., for the first generation of men to grow up in a more economically developed environment. There was no such upturn in women. Birth cohort effects were the main drivers of change in IHD mortality rates. CONCLUSION: IHD mortality rates are declining in Hong Kong and are projected to continue to do so, even taking into account greater vulnerability for the first generation of men born into a more developed environment. At the same time social disparities in IHD have reversed and are widening, partly as a result of a cohort effect, with corresponding implications for prevention.

  8. Beyond the beat: modeling metric structure in music and performance.

    Science.gov (United States)

    Tomic, Stefan T; Janata, Petr

    2008-12-01

    Current models for capturing metric structure of recordings of music are concerned primarily with the task of tempo and beat estimation. Even though these models have the potential for extracting other metric and rhythmic information, this potential has not been realized. In this paper, a model for describing the general metric structure of audio signals and behavioral data is presented. This model employs reson filters, rather than the comb filters used in earlier models. The oscillatory nature of reson filters is investigated, as they may be better suited for extracting multiple metric levels in the onset patterns of acoustic signals. The model is tested with several types of sequences of Dirac impulses as inputs, in order to investigate the model's sensitivity to timing variations and accent structure. The model's responses to natural stimuli are illustrated, both for excerpts of recorded music from a large database utilized by tempo-estimation models, and sequences of taps from a bimanual tapping task. Finally, the relationship of the model to several other beat-finding and rhythm models is discussed, and several applications and extensions for the model are suggested.

  9. Analysis of the forces acting on beating cilia

    Science.gov (United States)

    Sangani, Ashok S.; Vidyadharan, Jyothish; Foster, Kenneth W.

    2016-06-01

    Detailed analysis of the forces acting on a uniform-diameter beating cilium is carried out to determine the moment generated by the inter-doublet forces acting along the length of a cilium and the results are compared with the sliding-control theory according to which the moment is a function of the interdoublet sliding. In the central part of the cilium the inter-doublet forces are found to be proportional to the inter-doublet sliding. However, in spite of the uniformity of the diameter of the cilium, the proportionality constant, known as the dynamic stiffness, is not constant along its entire length. Significant variations are observed in the regions both near the tip of the cilium and proximal to the cell body. In the tip region the magnitude of the dynamic stiffness is found to decrease. This decrease is probably due to decrease in the number density of the molecular motors in that region and in the number of doublet microtubules. The behavior in the proximal region, on the other hand, does not appear to be well described by the sliding control theory. Our analysis therefore suggests that the dynamics of ciliary beating cannot be adequately described by a simple sliding-control theory with constant dynamic stiffness. Our analysis suggests that the cilium is differentiated into a basal region optimized for the creation of a wave and a central region optimized to support a traveling wave that provides the thrust for the cell.

  10. Light beating spectroscopy of Brillouin scattering in gases and solids

    Science.gov (United States)

    Yogi, Takeshi; Sakai, Keiji; Takagi, Kenshiro

    2006-07-01

    The experimental system of optical beating spectroscopy was improved, and the increased sensitivity and frequency resolution were demonstrated in the Brillouin scattering experiments in solids, crown glass (BK7), and polymethylmetacrylate (PMMA), and also in gases, air, and nitrogen. For their weak light scattering ability, these substances are very tough specimens for Brillouin scattering studies, and the classical spectrometer of Fabry-Pérot étalon has been so far used for the frequency analysis. The phonon peaks were observed with the present light beating system in BK7 at room temperature over the wave number range from k /2π=1.03×104to8.84×104m-1 (corresponding frequency from 61.6to548MHz), and the spectra were fitted with Gaussian curves since a condenser lens in the incident light path caused a large instrumental width that overwhelmed the intrinsic phonon width. The spectra in PMMA were analyzed with Voigt functions. The dispersion relations obtained in these solids were in good agreement with the literature values of ultrasonic velocity. The spectra in air were well fitted with Lorentzian curve representing the phonon lifetime, and the absorption as well as the phase velocity was obtained.

  11. Effect of Cilia Beat Frequency on Mucociliary Clearance

    Directory of Open Access Journals (Sweden)

    Sedaghat M. H.

    2016-12-01

    Full Text Available Background: The airway surface liquid (ASL, which is a fluid layer coating the interior epithelial surface of the bronchi and bronchiolesis, plays an important defensive role against foreign particles and chemicals entering lungs. Objective: Numerical investigation has been employed to solve two-layer model consisting of mucus layer as a viscoelastic fluid and periciliary liquid layer as a Newtonian fluid to study the effects of cilia beat frequency (CBF at various amounts of mucus properties on muco-ciliary transport problem. Methods: Hybrid finite difference-lattice Boltzmann-method (FB-LBM has been used to solve the momentum equations and to simulate cilia forces, and also the PCLmucus interface more accurately, immersed boundary method (IBM has been employed. The main contribution of the current study is to use an Oldroyd-B model as the constitutive equation of mucus. Results: Our results show that increasing CBF and decreasing mucus viscosity ratio have great effects on mucus flow, but the effect of viscosity ratio is more significant. The results also illustrate that the relation between cilia beat frequency and mean mucus velocity is almost linear and it has similar behavior at different values of viscosity ratio. Conclusion: Numerical investigation based on hybrid IB-FD-LBM has been used to study the effect of CBF at various mounts of mucus viscosity ratio on the muco-ciliary clearance. The results showed that the effect of viscosity ratio on the muco-ciliary transport process is more significant compared with CBF.

  12. Capturing structure and function in an embryonic heart with Biophotonic tools

    Directory of Open Access Journals (Sweden)

    Ganga eKarunamuni

    2014-09-01

    Full Text Available Disturbed cardiac function (flow, excitation, contraction, calcium transients at an early stage of development has been shown to correlate with and may lead to cellular/molecular, functional and structural cardiac anomalies at later stages culminating in the congenital heart defects (CHDs that present at birth. It is not surprising that cardiac function, which drives embryonic and extraembryonic circulation, is also connected to neural and placental development. While our knowledge of molecular and cellular steps in cardiac development is growing rapidly, our understanding of the role of cardiovascular function in the embryo is still rudimentary. One reason for the scanty information in this area is that the tools to study early cardiac function are limited. Recently developed and adapted Biophotonic tools may overcome the challenges of studying the tiny fragile beating heart. In this chapter, the strengths and limitations of Biophotonic tools will be described with emphasis on Optical Coherence Tomography (OCT. OCT can be used for detailed structural and functional studies of the tubular and looping avian embryo heart under physiological conditions. The same hearts can be subsequently rapidly and quantitatively phenotyped at a later stage using OCT. When combined with other tools such as Optimal Mapping (OM and Optical Pacing (OP, OCT has the potential to reveal in spatial and temporal detail the biophysical changes that can potentially impact mechanotransduction pathways. This information may provide better explanations for the etiology of the CHDs when interwoven with our understanding of the multiple molecular pathways that have been described to be involved. Examples of application of these tools to study the etiology of CHDs are presented. Directions for future directions and advances in the use of Biophotonic tools are discussed.

  13. Heart Anatomy

    Science.gov (United States)

    ... kilometers), which is far enough to circle the earth more than twice! See also on other sites: ... For the Public Heart Information Center Project Heart Women’s Heart Health Clinical Trials 6770 Bertner Avenue Houston, ...

  14. Heart Transplant

    Science.gov (United States)

    ... your transplanted heart. You should also have routine medical checkups to maintain overall health. Activity Restrictions Heart transplant recipients have no specific activity restrictions. Discuss activity ideas with your ... to some medical and dental procedures to prevent endocarditis, most heart ...

  15. Cardiac mast cells regulate myocyte ANP release via histamine H2 receptor in beating rabbit atria.

    Science.gov (United States)

    Li, Dan; Wen, Jin Fu; Jin, Jing Yu; Quan, He Xiu; Cho, Kyung Woo

    2009-06-05

    It has been shown that histamine inhibits atrial natriuretic peptide (ANP) release. Because cardiac mast cells are the principal source of histamine in the heart, we hypothesized that cardiac mast cells are involved in the regulation of atrial ANP release. To test the hypothesis, experiments were performed in perfused beating rabbit atria allowing atrial pacing and measurements of changes in atrial stroke volume, intraatrial pulse pressure and myocyte ANP release. Mast cell degranulation with Compound 48/80 decreased atrial myocyte ANP release, and the response was blocked by a selective histamine H(2) receptor blocker, cimetidine, indicating that histamine was responsible for the decrease in ANP release. Mast cell stabilization with cromolyn blocked the Compound 48/80-induced decrease in ANP release. These data suggest that mast cell-derived histamine is involved in the regulation of cardiac ANP release. Thus, the cardiac mast cell-cardiomyocyte communication via the histamine-ANP pathway may implicate in the cardiac disorder associated with mast cell degranulation such as in acute coronary syndrome or cardiac hypertrophy.

  16. Resting heart rate and the risk of heart failure in healthy adults: the Rotterdam Study.

    Science.gov (United States)

    Nanchen, David; Leening, Maarten J G; Locatelli, Isabella; Cornuz, Jacques; Kors, Jan A; Heeringa, Jan; Deckers, Jaap W; Hofman, Albert; Franco, Oscar H; Stricker, Bruno H Ch; Witteman, Jacqueline C M; Dehghan, Abbas

    2013-05-01

    An elevated resting heart rate is associated with rehospitalization for heart failure and is a modifiable risk factor in heart failure patients. We aimed to examine the association between resting heart rate and incident heart failure in a population-based cohort study of healthy adults without pre-existing overt heart disease. We studied 4768 men and women aged ≥55 years from the population-based Rotterdam Study. We excluded participants with prevalent heart failure, coronary heart disease, pacemaker, atrial fibrillation, atrioventricular block, and those using β-blockers or calcium channel blockers. We used extended Cox models allowing for time-dependent variation of resting heart rate along follow-up. During a median of 14.6 years of follow-up, 656 participants developed heart failure. The risk of heart failure was higher in men with higher resting heart rate. For each increment of 10 beats per minute, the multivariable adjusted hazard ratios in men were 1.16 (95% confidence interval, 1.05-1.28; P=0.005) in the time-fixed heart rate model and 1.13 (95% confidence interval, 1.02-1.25; P=0.017) in the time-dependent heart rate model. The association could not be demonstrated in women (P for interaction=0.004). Censoring participants for incident coronary heart disease or using time-dependent models to account for the use of β-blockers or calcium channel blockers during follow-up did not alter the results. Baseline or persistent higher resting heart rate is an independent risk factor for the development of heart failure in healthy older men in the general population.

  17. Congenital Heart Disease: Causes, Diagnosis, Symptoms, and Treatments.

    Science.gov (United States)

    Sun, RongRong; Liu, Min; Lu, Lei; Zheng, Yi; Zhang, Peiying

    2015-07-01

    The congenital heart disease includes abnormalities in heart structure that occur before birth. Such defects occur in the fetus while it is developing in the uterus during pregnancy. About 500,000 adults have congenital heart disease in USA (WebMD, Congenital heart defects medications, www.WebMD.com/heart-disease/tc/congenital-heart-defects-medications , 2014). 1 in every 100 children has defects in their heart due to genetic or chromosomal abnormalities, such as Down syndrome. The excessive alcohol consumption during pregnancy and use of medications, maternal viral infection, such as Rubella virus, measles (German), in the first trimester of pregnancy, all these are risk factors for congenital heart disease in children, and the risk increases if parent or sibling has a congenital heart defect. These are heart valves defects, atrial and ventricular septa defects, stenosis, the heart muscle abnormalities, and a hole inside wall of the heart which causes defect in blood circulation, heart failure, and eventual death. There are no particular symptoms of congenital heart disease, but shortness of breath and limited ability to do exercise, fatigue, abnormal sound of heart as heart murmur, which is diagnosed by a physician while listening to the heart beats. The echocardiogram or transesophageal echocardiogram, electrocardiogram, chest X-ray, cardiac catheterization, and MRI methods are used to detect congenital heart disease. Several medications are given depending on the severity of this disease, and catheter method and surgery are required for serious cases to repair heart valves or heart transplantation as in endocarditis. For genetic study, first DNA is extracted from blood followed by DNA sequence analysis and any defect in nucleotide sequence of DNA is determined. For congenital heart disease, genes in chromosome 1 show some defects in nucleotide sequence. In this review the causes, diagnosis, symptoms, and treatments of congenital heart disease are described.

  18. Interacting cortical and basal ganglia networks underlying finding and tapping to the musical beat.

    Science.gov (United States)

    Kung, Shu-Jen; Chen, Joyce L; Zatorre, Robert J; Penhune, Virginia B

    2013-03-01

    Humans are able to find and tap to the beat of musical rhythms varying in complexity from children's songs to modern jazz. Musical beat has no one-to-one relationship with auditory features-it is an abstract perceptual representation that emerges from the interaction between sensory cues and higher-level cognitive organization. Previous investigations have examined the neural basis of beat processing but have not tested the core phenomenon of finding and tapping to the musical beat. To test this, we used fMRI and had musicians find and tap to the beat of rhythms that varied from metrically simple to metrically complex-thus from a strong to a weak beat. Unlike most previous studies, we measured beat tapping performance during scanning and controlled for possible effects of scanner noise on beat perception. Results showed that beat finding and tapping recruited largely overlapping brain regions, including the superior temporal gyrus (STG), premotor cortex, and ventrolateral PFC (VLPFC). Beat tapping activity in STG and VLPFC was correlated with both perception and performance, suggesting that they are important for retrieving, selecting, and maintaining the musical beat. In contrast BG activity was similar in all conditions and was not correlated with either perception or production, suggesting that it may be involved in detecting auditory temporal regularity or in associating auditory stimuli with a motor response. Importantly, functional connectivity analyses showed that these systems interact, indicating that more basic sensorimotor mechanisms instantiated in the BG work in tandem with higher-order cognitive mechanisms in PFC.

  19. Platelet function changes as monitored by cone and plate(let) analyzer during beating heart surgery.

    Science.gov (United States)

    Gerrah, Rabin; Snir, Eitan; Brill, Alex; Varon, David

    2004-01-01

    Off-pump coronary artery bypass (OPCAB) is believed to reduce cardiopulmonary bypass (CPB)-related complications, including platelet damage. A hypercoagulable state instead of coagulopathy has been reported following OPCAB surgeries due to CPB. Whether platelet function is changed when the injurious effect of CPB is eliminated was investigated. Platelet function was determined with the cone and plate(let) analyzer (CPA) method. The 2 parameters, average size (AS) and surface coverage (SC) of platelet aggregates, were measured with the CPA method to assess platelet aggregation and adhesion. These parameters were evaluated, and their values were compared at several stages of OPCAB surgery. The correlations of postoperative bleeding with platelet function at different stages of the surgery and with other factors, such as platelet count, hematocrit, and transfusions, were studied. Both AS and SC increased during several stages of the operation, and postoperative values (mean +/- SD) were significantly higher than preoperative values (30.4 +/- 8.1 microm 2 versus 23.3 +/- 6.9 microm 2 for AS [ P =.02] and 7.6% +/- 3.6% versus 5.2% +/- 1.8% for SC [ P =.04]). The mean total bleeding volume was 875 micro 415 mL. Preoperative AS and SC were the only parameters significantly ( P =.01) and linearly ( r = 0.7) related to postoperative bleeding. An increased platelet function, as determined by the CPA method, is found following OPCAB surgery. This phenomenon is probably at least partially responsible for the thrombogenic state after OPCAB surgery. Lack of platelet injury attributed to CPB may divert the system toward a more thrombogenic state. Preoperative platelet function, as evaluated by the CPA method, is an independent risk factor determining postoperative bleeding.

  20. A tiny heart beating: Student-edited legal periodicals in good ol' Europe

    OpenAIRE

    Russi, L.; Longobardi, F.

    2009-01-01

    This paper has a twofold aim: to analyze the possible opportunities disclosed by the observed growth of student- dited law reviews in Europe and to propose an innovative model of student participation to legal publication. The first part explores the phenomenon of student-edited law reviews in the U.S., focusing on its recognized educational benefits. Among others, it is observed that participation in student-edited law reviews might promote greater scholarly maturity among J.D. students, who...

  1. Mimo pillow--an intelligent cushion designed with maternal heart beat vibrations for comforting newborn infants.

    Science.gov (United States)

    Chen, Wei; Oetomo, Sidarto Bambang; Tetteroo, Daniel; Versteegh, Frank; Mamagkaki, Thelxi; Pereira, Mariana Serras; Janssen, Lindy; van Meurs, Andrea

    2015-05-01

    Premature infants are subject to numerous interventions ranging from a simple diaper change to surgery while residing in neonatal intensive care units. These neonates often suffer from pain, distress, and discomfort during the first weeks of their lives. Although pharmacological pain treatment often is available, it cannot always be applied to relieve a neonate from pain or discomfort. This paper describes a nonpharmacological solution, called Mimo, which provides comfort through mediation of a parent's physiological features to the distressed neonate via an intelligent pillow system embedded with sensing and actuating functions. We present the design, the implementation, and the evaluation of the prototype. Clinical tests at Máxima Medical Center in the Netherlands show that among the nine of ten infants who showed discomfort following diaper change, a shorter recovery time to baseline skin conductance analgesimeter values could be measured when the maternal heartbeat vibration in the Mimo was switched ON and in seven of these ten a shorter crying time was measured.

  2. Sarco/endoplasmic reticulum Ca2+ (SERCA)-pumps: link to heart beats and calcium waves.

    Science.gov (United States)

    Misquitta, C M; Mack, D P; Grover, A K

    1999-04-01

    Mobilization of endoplasmic reticulum Ca2+ is pivotal to the ability of a cell to send or respond to stimuli. Ca(2+)-Mg(2+)-ATPases, termed SERCA pumps, sequester Ca2+ into the sarco/endoplasmic reticulum. There are several SERCA protein isoforms encoded by three genes. This paper summarizes the structure, function, tissue and subcellular distribution, and regulation of various SERCA isoforms. Then it attempts to link divergence in the signal transduction processes of cells to the types and levels of SERCA proteins they express and to how the cells regulate their SERCA pump activity. The paper examines possible linkages between SERCA pumps and receptor-activated Ca2+ entry, SERCA isoform localization and Ca(2+)-waves, and the role of SERCA pumps in nuclear Ca2+ in cell proliferation and apoptosis. Then it uses available information on cardiac function and chronic stimulation of the fast-twitch muscle to answer a series of basic questions on the regulation of SERCA activity and expression and their linkage to signal transduction. Finally, it discusses the possibility that neurons exhibit complex Ca(2+)-waves whose interactions have the potential to explain the operational basis of neural networks. A series of unanswered questions emerge based on this synthesis, including the unsettling issue of whether all the isoforms are needed to achieve the divergence in signal transduction or if there is a degree of redundancy in the system.

  3. A novel approach for the averaging of magnetocardiographically recorded heart beats

    Energy Technology Data Exchange (ETDEWEB)

    DiPietroPaolo, D [Advanced Technologies Biomagnetics, Pescara (Italy); Mueller, H-P [Division for Biosignals and Imaging Technologies, Central Institute for Biomedical Engineering, Ulm University, D-89069 Ulm (Germany); Erne, S N [Division for Biosignals and Imaging Technologies, Central Institute for Biomedical Engineering, Ulm University, D-89069 Ulm (Germany)

    2005-05-21

    Performing signal averaging in an efficient and correct way is indispensable since it is a prerequisite for a broad variety of magnetocardiographic (MCG) analysis methods. One of the most common procedures for performing the signal averaging to increase the signal-to-noise ratio (SNR) in magnetocardiography, as well as in electrocardiography (ECG), is done by means of spatial or temporal techniques. In this paper, an improvement of the temporal averaging method is presented. In order to obtain an accurate signal detection, temporal alignment methods and objective classification criteria are developed. The processing technique based on hierarchical clustering is introduced to take into account the non-stationarity of the noise and, to some extent, the biological variability of the signals reaching the optimum SNR. The method implemented is especially designed to run fast and does not require any interaction from the operator. The averaging procedure described in this work is applied to the averaging of MCG data as an example, but with its intrinsic properties it can also be applied to the averaging of ECG recording, averaging of body-surface-potential mapping (BSPM) and averaging of magnetoencephalographic (MEG) or electroencephalographic (EEG) signals.

  4. Imminent brain death: Point of departure for potential heart-beating organ donor recognition

    NARCIS (Netherlands)

    Y.J. de Groot (Yorick); N.E. Jansen (Nichon); J. Bakker (Jan); M.A. Kuiper (Michael); S. Aerdts (Stan); A.I.R. Maas (Andrew); E.F.M. Wijdicks (Eelco); H.A. van Leiden (Hendrik); A.J. Hoitsma (Andries); H.P.H. Kremer (Berry); E.J.O. Kompanje (Erwin)

    2010-01-01

    textabstractPurpose: There is, in European countries that conduct medical chart review of intensive care unit (ICU) deaths, no consensus on uniform criteria for defining a potential organ donor. Although the term is increasingly being used in recent literature, it is seldom defined in detail. We

  5. "My Heart Beats in Two Places": Immigration Stories in Korean-American Picture Books

    Science.gov (United States)

    Yi, Joanne H.

    2014-01-01

    This article examines the impact of immigration on Korean children through a content and literary analysis of 14 children's picture books. A majority of published children's literature dealing with the subject of Korean Americans or Korean immigration contains culturally specific themes common to the Korean immigration experience. These…

  6. Environmental and occupational particulate matter exposures and ectopic heart beats in welders.

    Science.gov (United States)

    Cavallari, Jennifer M; Fang, Shona C; Eisen, Ellen A; Mittleman, Murray A; Christiani, David C

    2016-07-01

    Links between arrhythmias and particulate matter exposures have been found among sensitive populations. We examined the relationship between personal particulate matter ≤2.5 µm aerodynamic diameter (PM2.5) exposures and ectopy in a panel study of healthy welders. Simultaneous ambulatory ECG and personal PM2.5 exposure monitoring with DustTrak Aerosol Monitor was performed on 72 males during work and non-work periods for 5-90 h (median 40 h). ECGs were summarised hourly for supraventricular ectopy (SVE) and ventricular ectopy (VE). PM2.5 exposures both work and non-work periods were averaged hourly with lags from 0 to 7 h. Generalised linear mixed-effects models with a random participant intercept were used to examine the relationship between PM2.5 exposure and the odds of SVE or VE. Sensitivity analyses were performed to assess whether relationships differed by work period and among current smokers. Participants had a mean (SD) age of 38 (11) years and were monitored over 2993 person-hours. The number of hourly ectopic events was highly skewed with mean (SD) of 14 (69) VE and 1 (4) SVE. We found marginally significant increases in VE with PM2.5 exposures in the sixth and seventh hour lags, yet no association with SVE. For every 100 μg/m(3) increase in sixth hour lagged PM2.5, the adjusted OR (95% CI) for VE was 1.03 (1.00 to 1.05). Results persisted in work or non-work exposure periods and non-smokers had increased odds of VE associated with PM2.5 as compared with smokers. A small increase in the odds of VE with short-term PM2.5 exposure was observed among relatively healthy men with environmental and occupational exposures. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

  7. Optimizing clinical risk stratification in acute heart failure

    NARCIS (Netherlands)

    Demissei, Biniyam Gemechu

    2017-01-01

    Heart failure occurs when the heart is unable to pump sufficiently to maintain blood flow to meet the body's needs. Acute heart failure is defined as a rapid onset of signs and symptoms of heart failure resulting in the need for urgent medical treatment. Acute heart failure is associated with

  8. Effect of heart rate on the hemodynamics of bileaflet mechanical heart valves' prostheses (St. Jude Medical) in the aortic position and in the opening phase: A computational study.

    Science.gov (United States)

    Jahandardoost, Mehdi; Fradet, Guy; Mohammadi, Hadi

    2016-03-01

    To date, to the best of the authors' knowledge, in almost all of the studies performed around the hemodynamics of bileaflet mechanical heart valves, a heart rate of 70-72 beats/min has been considered. In fact, the heart rate of ~72 beats/min does not represent the entire normal physiological conditions under which the aortic or prosthetic valves function. The heart rates of 120 or 50 beats/min may lead to hemodynamic complications, such as plaque formation and/or thromboembolism in patients. In this study, the hemodynamic performance of the bileaflet mechanical heart valves in a wide range of normal and physiological heart rates, that is, 60-150 beats/min, was studied in the opening phase. The model considered in this study was a St. Jude Medical bileaflet mechanical heart valve with the inner diameter of 27 mm in the aortic position. The hemodynamics of the native valve and the St. Jude Medical valve were studied in a variety of heart rates in the opening phase and the results were carefully compared. The results indicate that peak values of the velocity profile downstream of the valve increase as heart rate increases, as well as the location of the maximum velocity changes with heart rate in the St. Jude Medical valve model. Also, the maximum values of shear stress and wall shear stresses downstream of the valve are proportional to heart rate in both models. Interestingly, the maximum shear stress and wall shear stress values in both models are in the same range when heart rate is valve model when heart rate is >90 beats/min (up to ~40% growth compared to that of the native valve). The findings of this study may be of importance in the hemodynamic performance of bileaflet mechanical heart valves. They may also play an important role in design improvement of conventional prosthetic heart valves and the design of the next generation of prosthetic valves, such as percutaneous valves. © IMechE 2016.

  9. Autonomic control of heart rate by metabolically sensitive skeletal muscle afferents in humans

    DEFF Research Database (Denmark)

    Fisher, James P; Seifert, Thomas; Hartwich, Doreen

    2010-01-01

    Isolated activation of metabolically sensitive skeletal muscle afferents (muscle metaboreflex) using post-exercise ischaemia (PEI) following handgrip partially maintains exercise-induced increases in arterial blood pressure (BP) and muscle sympathetic nerve activity (SNA), while heart rate (HR...... of cardiac parasympathetic reactivation on heart rate....... moderate (PEI-M) and high (PEI-H) intensity isometric handgrip performed at 25% and 40% maximum voluntary contraction, under control (no drug), parasympathetic blockade (glycopyrrolate) and beta-adrenergic blockade (metoprolol or propranalol) conditions, while beat-to-beat HR and BP were continuously...

  10. Direct Visualization of Mechanical Beats by Means of an Oscillating Smartphone

    Science.gov (United States)

    Giménez, Marcos H.; Salinas, Isabel; Monsoriu, Juan A.; Castro-Palacio, Juan C.

    2017-10-01

    The resonance phenomenon is widely known in physics courses. Qualitatively speaking, resonance takes place in a driven oscillating system whenever the frequency approaches the natural frequency, resulting in maximal oscillatory amplitude. Very closely related to resonance is the phenomenon of mechanical beating, which occurs when the driving and natural frequencies of the system are slightly different. The frequency of the beat is just the difference of the natural and driving frequencies. Beats are very familiar in acoustic systems. There are several works in this journal on visualizing the beats in acoustic systems. For instance, the microphone and the speaker of two mobile devices were used in previous work to analyze the acoustic beats produced by two signals of close frequencies. The formation of beats can also be visualized in mechanical systems, such as a mass-spring system or a double-driven string. Here, the mechanical beats in a smartphone-spring system are directly visualized in a simple way. The frequency of the beats is measured by means of the acceleration sensor of a smartphone, which hangs from a spring attached to a mechanical driver. This laboratory experiment is suitable for both high school and first-year university physics courses.

  11. The evolutionary neuroscience of musical beat perception: the Action Simulation for Auditory Prediction (ASAP) hypothesis.

    Science.gov (United States)

    Patel, Aniruddh D; Iversen, John R

    2014-01-01

    a perceived periodic pulse that structures the perception of musical rhythm and which serves as a framework for synchronized movement to music. What are the neural mechanisms of musical beat perception, and how did they evolve? One view, which dates back to Darwin and implicitly informs some current models of beat perception, is that the relevant neural mechanisms are relatively general and are widespread among animal species. On the basis of recent neural and cross-species data on musical beat processing, this paper argues for a different view. Here we argue that beat perception is a complex brain function involving temporally-precise communication between auditory regions and motor planning regions of the cortex (even in the absence of overt movement). More specifically, we propose that simulation of periodic movement in motor planning regions provides a neural signal that helps the auditory system predict the timing of upcoming beats. This "action simulation for auditory prediction" (ASAP) hypothesis leads to testable predictions. We further suggest that ASAP relies on dorsal auditory pathway connections between auditory regions and motor planning regions via the parietal cortex, and suggest that these connections may be stronger in humans than in non-human primates due to the evolution of vocal learning in our lineage. This suggestion motivates cross-species research to determine which species are capable of human-like beat perception, i.e., beat perception that involves accurate temporal prediction of beat times across a fairly broad range of tempi.

  12. Beat sampling accuracy in estimating spruce spider mite (Acari: Tetranychidae) populations and injury on juniper.

    Science.gov (United States)

    Shrewsbury, Paula M; Hardin, Mark R

    2004-08-01

    The use of a standardized beat sampling method for estimating spruce spider mite, Oligonychus ununguis (Jacobi) (Acari: Tetranychidae), densities on a widely used evergreen ornamental plant species, Juniperus chinensis variety 'Sargentii' A. Henry (Cupressaceae), was examined. There was a significant positive relationship between total spruce spider mite densities and spider mite densities from beat sampling on juniper. The slope and intercept of the relationship may be used by pest managers to predict total spider mite densities on plants from beat sample counts. Beat sampling dramatically underestimates the total number of spider mites on a foliage sample. The relationships between spruce spider mite feeding injury and spider mite density estimates from beat sampling juniper foliage and total spider mite counts on foliage were also examined. There was a significant positive relationship between spruce spider mite density as estimated from beat sampling and injury to the plants. There was a similar positive relationship between the total number of spruce spider mites and injury to the plants, suggesting that a pest manager could use beat sampling counts to estimate plant injury and related thresholds. These findings have important implications to decision-making for spruce spider mite control, especially as it relates to threshold levels and determining rates of predator releases. Further assessment of the effectiveness of beat and other sampling methods across multiple spider mite- host plant associations needs to be examined to enable pest managers to select sampling plans that are feasible and reliable.

  13. Beat processing is pre-attentive for metrically simple rhythms with clear accents: an ERP study.

    Directory of Open Access Journals (Sweden)

    Fleur L Bouwer

    Full Text Available The perception of a regular beat is fundamental to music processing. Here we examine whether the detection of a regular beat is pre-attentive for metrically simple, acoustically varying stimuli using the mismatch negativity (MMN, an ERP response elicited by violations of acoustic regularity irrespective of whether subjects are attending to the stimuli. Both musicians and non-musicians were presented with a varying rhythm with a clear accent structure in which occasionally a sound was omitted. We compared the MMN response to the omission of identical sounds in different metrical positions. Most importantly, we found that omissions in strong metrical positions, on the beat, elicited higher amplitude MMN responses than omissions in weak metrical positions, not on the beat. This suggests that the detection of a beat is pre-attentive when highly beat inducing stimuli are used. No effects of musical expertise were found. Our results suggest that for metrically simple rhythms with clear accents beat processing does not require attention or musical expertise. In addition, we discuss how the use of acoustically varying stimuli may influence ERP results when studying beat processing.

  14. 77 FR 19015 - Announcement of Requirements and Registration for Beat Down Blood Pressure Challenge

    Science.gov (United States)

    2012-03-29

    ... and Registration for Beat Down Blood Pressure Challenge AGENCY: Office of the National Coordinator for.../28, we encourage you to visit http://BloodPressure.Challenge.gov for a complete set of rules and... the Federal Register (77 FR 17060) announcing requirements and registration for a Beat Down Blood...

  15. The prognostic significance of heart rate in patients hospitalized for heart failure with reduced ejection fraction in sinus rhythm: insights from the EVEREST (Efficacy of Vasopressin Antagonism in Heart Failure: Outcome Study With Tolvaptan) trial.

    Science.gov (United States)

    Greene, Stephen J; Vaduganathan, Muthiah; Wilcox, Jane E; Harinstein, Matthew E; Maggioni, Aldo P; Subacius, Haris; Zannad, Faiez; Konstam, Marvin A; Chioncel, Ovidiu; Yancy, Clyde W; Swedberg, Karl; Butler, Javed; Bonow, Robert O; Gheorghiade, Mihai

    2013-12-01

    The purpose of this study was to characterize the relationship between heart rate and post-discharge outcomes in patients with hospitalization for heart failure (HHF) with reduced ejection fraction (EF) in sinus rhythm. A reduction in heart rate improves clinical outcomes in patients with chronic heart failure and in sinus rhythm, but the association between heart rate and post-discharge outcomes in patients with HHF is presently unclear. This post-hoc analysis of the EVEREST (Efficacy of Vasopressin Antagonism in Heart Failure: Outcome Study With Tolvaptan) trial examined 1,947 patients with HHF and EF ≤40% not in atrial fibrillation/flutter or pacemaker dependent. The median follow-up period was 9.9 months. At baseline, patients with a higher heart rate tended to be younger with lower EF and were more likely to have worse New York Heart Association functional class and higher natriuretic peptide levels. After adjustment for clinical risk factors, baseline heart rate was not predictive of all-cause mortality (p ≥ 0.066). However, at ≥70 beats/min, every 5-beat increase in 1-week post-discharge heart rate was independently associated with increased all-cause mortality (hazard ratio: 1.13 [95% confidence interval: 1.05 to 1.22]; p = 0.002). Similarly, every 5-beat increase ≥70 beats/min in 4-week post-discharge heart rate was predictive of all-cause mortality (hazard ratio: 1.12 [95% confidence interval: 1.05 to 1.19]; p = 0.001). In this large cohort of patients with HHF with reduced EF and in sinus rhythm, baseline heart rate did not correlate with all-cause mortality. In contrast, at ≥70 beats/min, higher heart rate in the early post-discharge period was independently predictive of death during subsequent follow-up. Further study of post-discharge heart rate as a potential therapeutic target in this high-risk population is encouraged. Copyright © 2013 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

  16. The quantum beat principles and applications of atomic clocks

    CERN Document Server

    Major, F

    2007-01-01

    This work attempts to convey a broad understanding of the physical principles underlying the workings of these quantum-based atomic clocks, with introductory chapters placing them in context with the early development of mechanical clocks and the introduction of electronic time-keeping as embodied in the quartz-controlled clocks. While the book makes no pretense at being a history of atomic clocks, it nevertheless takes a historical perspective in its treatment of the subject. Intended for nonspecialists with some knowledge of physics or engineering, The Quantum Beat covers a wide range of salient topics relevant to atomic clocks, treated in a broad intuitive manner with a minimum of mathematical formalism. Detailed descriptions are given of the design principles of the rubidium, cesium, hydrogen maser, and mercury ion standards; the revolutionary changes that the advent of the laser has made possible, such as laser cooling, optical pumping, the formation of "optical molasses," and the cesium "fountain" stand...

  17. MD 979: Beta-beating measurements on colliding beams

    CERN Document Server

    Goncalves Jorge, Patrik; Pieloni, Tatiana; Buffat, Xavier; Carlier, Felix Simon; Coello De Portugal - Martinez Vazquez, Jaime Maria; Fol, Elena; Langner, Andy Sven; Medina Medrano, Luis Eduardo; Olexa, Jakub; Tomas Garcia, Rogelio; Valuch, Daniel; Wegscheider, Andreas; CERN. Geneva. ATS Department

    2017-01-01

    The HL-LHC high brightness beams will give a large β-beating due to the head-on and long-range interactions since a beam-beam parameter of 0.01 per Interaction Point (IP) is expected. The β-heating induced by two head-on collision reaches 15%. A third IP, i.e. IP8, could bring the β-heating up to 24%. The aim of the Machine Development (MD) study was to test optics measurements with AC dipole and ADT on colliding beams at injection and to implement a correction of the β-heating due to to head-on collision in the two experiments IP1&5. Int his note, we summarize the first results of this test performed in the LHC.

  18. Effect of Cilia Beat Frequency on Muco-ciliary Clearance

    Science.gov (United States)

    Sedaghat, M.H.; Shahmardan, M.M.; Norouzi, M.; Heydari, M.

    2016-01-01

    Background: The airway surface liquid (ASL), which is a fluid layer coating the interior epithelial surface of the bronchi and bronchiolesis, plays an important defensive role against foreign particles and chemicals entering lungs. Objective: Numerical investigation has been employed to solve two-layer model consisting of mucus layer as a viscoelastic fluid and periciliary liquid layer as a Newtonian fluid to study the effects of cilia beat frequency (CBF) at various amounts of mucus properties on muco-ciliary transport problem. Methods: Hybrid finite difference-lattice Boltzmann-method (FB-LBM) has been used to solve the momentum equations and to simulate cilia forces, and also the PCL-mucus interface more accurately, immersed boundary method (IBM) has been employed. The main contribution of the current study is to use an Oldroyd-B model as the constitutive equation of mucus. Results: Our results show that increasing CBF and decreasing mucus viscosity ratio have great effects on mucus flow, but the effect of viscosity ratio is more significant. The results also illustrate that the relation between cilia beat frequency and mean mucus velocity is almost linear and it has similar behavior at different values of viscosity ratio. Conclusion: Numerical investigation based on hybrid IB-FD-LBM has been used to study the effect of CBF at various mounts of mucus viscosity ratio on the muco-ciliary clearance. The results showed that the effect of viscosity ratio on the muco-ciliary transport process is more significant compared with CBF. PMID:28144596

  19. Direct visualization of mechanical beats by means of an oscillating smartphone

    CERN Document Server

    Giménez, Marcos H; Monsoriu, Juan A

    2016-01-01

    The resonance phenomenon is widely known from Physics courses. Qualitatively speaking, it takes place in a driven oscillating system whenever the driven frequency approaches the natural frequency. It is when the amplitude of the oscillations become maximal. Very closely related to this phenomenon, there is another which is very surprising too. It takes place when the driven and natural frequencies of the system are slightly different and interfere constructively and destructively, forming the so called beats. The frequency of the beats is just the difference of the interfering waves frequencies. Beats are very noticeable in acoustic systems. We all have probably perceived them in the form of periodic ups and downs in the sound intensity volume. There are several works in this journal on visualizing the beats in acoustic systems. For instance, the microphone and the speaker of two mobile devices were used in previous work to analyze the acoustic beat produced by two signals of close frequencies. The formation ...

  20. More attentional focusing through binaural beats: evidence from the global-local task.

    Science.gov (United States)

    Colzato, Lorenza S; Barone, Hayley; Sellaro, Roberta; Hommel, Bernhard

    2017-01-01

    A recent study showed that binaural beats have an impact on the efficiency of allocating attention over time. We were interested to see whether this impact affects attentional focusing or, even further, the top-down control over irrelevant information. Healthy adults listened to gamma-frequency (40 Hz) binaural beats, which are assumed to increase attentional concentration, or a constant tone of 340 Hz (control condition) for 3 min before and during a global-local task. While the size of the congruency effect (indicating the failure to suppress task-irrelevant information) was unaffected by the binaural beats, the global-precedence effect (reflecting attentional focusing) was considerably smaller after gamma-frequency binaural beats than after the control condition. Our findings suggest that high-frequency binaural beats bias the individual attentional processing style towards a reduced spotlight of attention.

  1. Heart Diseases

    Science.gov (United States)

    ... you're like most people, you think that heart disease is a problem for others. But heart disease is the number one killer in the ... of disability. There are many different forms of heart disease. The most common cause of heart disease ...

  2. Heart Transplantation

    Science.gov (United States)

    A heart transplant removes a damaged or diseased heart and replaces it with a healthy one. The healthy heart comes from a donor who has died. It is the last resort for people with heart failure when all other treatments have failed. The ...

  3. Heart Attack

    Science.gov (United States)

    Each year almost 800,000 Americans have a heart attack. A heart attack happens when blood flow to the heart suddenly ... it's important to know the symptoms of a heart attack and call 9-1-1 if you or ...

  4. Increased Short-Term Beat-to-Beat QT Interval Variability in Patients with Impaired Glucose Tolerance

    Directory of Open Access Journals (Sweden)

    Andrea Orosz

    2017-06-01

    Full Text Available Prediabetic states and diabetes are important risk factors for cardiovascular morbidity and mortality. Determination of short-term QT interval variability (STVQT is a non-invasive method for assessment of proarrhythmic risk. The aim of the study was to evaluate the STVQT in patients with impaired glucose tolerance (IGT. 18 IGT patients [age: 63 ± 11 years, body mass index (BMI: 31 ± 6 kg/m2, fasting glucose: 6.0 ± 0.4 mmol/l, 120 min postload glucose: 9.0 ± 1.0 mmol/l, hemoglobin A1c (HbA1c: 5.9 ± 0.4%; mean ± SD] and 18 healthy controls (age: 56 ± 9 years, BMI: 27 ± 5 kg/m2, fasting glucose: 5.2 ± 0.4 mmol/l, 120 min postload glucose: 5.5 ± 1.3 mmol/l, HbA1c: 5.4 ± 0.3% were enrolled into the study. ECGs were recorded, processed, and analyzed off-line. The RR and QT intervals were expressed as the average of 30 consecutive beats, the temporal instability of beat-to-beat repolarization was characterized by calculating STVQT as follows: STVQT = Σ|QTn + 1 − QTn| (30x√2−1. Autonomic function was assessed by means of standard cardiovascular reflex tests. There were no differences between IGT and control groups in QT (411 ± 43 vs 402 ± 39 ms and QTc (431 ± 25 vs 424 ± 19 ms intervals or QT dispersion (44 ± 13 vs 42 ± 17 ms. However, STVQT was significantly higher in IGT patients (5.0 ± 0.7 vs 3.7 ± 0.7, P < 0.0001. The elevated temporal STVQT in patients with IGT may be an early indicator of increased instability of cardiac repolarization during prediabetic conditions.

  5. Increased Short-Term Beat-to-Beat QT Interval Variability in Patients with Impaired Glucose Tolerance.

    Science.gov (United States)

    Orosz, Andrea; Baczkó, István; Nyiraty, Szabolcs; Körei, Anna E; Putz, Zsuzsanna; Takács, Róbert; Nemes, Attila; Várkonyi, Tamás T; Balogh, László; Ábrahám, György; Kempler, Péter; Papp, Julius Gy; Varró, András; Lengyel, Csaba

    2017-01-01

    Prediabetic states and diabetes are important risk factors for cardiovascular morbidity and mortality. Determination of short-term QT interval variability (STVQT) is a non-invasive method for assessment of proarrhythmic risk. The aim of the study was to evaluate the STVQT in patients with impaired glucose tolerance (IGT). 18 IGT patients [age: 63 ± 11 years, body mass index (BMI): 31 ± 6 kg/m2, fasting glucose: 6.0 ± 0.4 mmol/l, 120 min postload glucose: 9.0 ± 1.0 mmol/l, hemoglobin A1c (HbA1c): 5.9 ± 0.4%; mean ± SD] and 18 healthy controls (age: 56 ± 9 years, BMI: 27 ± 5 kg/m2, fasting glucose: 5.2 ± 0.4 mmol/l, 120 min postload glucose: 5.5 ± 1.3 mmol/l, HbA1c: 5.4 ± 0.3%) were enrolled into the study. ECGs were recorded, processed, and analyzed off-line. The RR and QT intervals were expressed as the average of 30 consecutive beats, the temporal instability of beat-to-beat repolarization was characterized by calculating STVQT as follows: STVQT = Σ|QTn + 1 - QTn| (30x√2)-1. Autonomic function was assessed by means of standard cardiovascular reflex tests. There were no differences between IGT and control groups in QT (411 ± 43 vs 402 ± 39 ms) and QTc (431 ± 25 vs 424 ± 19 ms) intervals or QT dispersion (44 ± 13 vs 42 ± 17 ms). However, STVQT was significantly higher in IGT patients (5.0 ± 0.7 vs 3.7 ± 0.7, P < 0.0001). The elevated temporal STVQT in patients with IGT may be an early indicator of increased instability of cardiac repolarization during prediabetic conditions.

  6. smRithm: Graphical user interface for heart rate variability analysis.

    Science.gov (United States)

    Nara, Sanjeev; Kaur, Manvinder; Datta, Saurav

    2015-01-01

    Over the past 25 years, Heart rate variability (HRV) has become a non-invasive research and clinical tool for indirectly carrying out investigation of both cardiac and autonomic system function in both healthy and diseased. It provides valuable information about a wide range of cardiovascular disorders, pulmonary diseases, neurological diseases, etc. Its primary purpose is to access the functioning of the nervous system. The source of information for HRV analysis is the continuous beat to beat measurement of inter-beat intervals. The electrocardiography (ECG or EKG) is considered as the best way to measure inter-beat intervals. This paper proposes an open source Graphical User Interface (GUI): smRithm developed in MATLAB for HRV analysis that will apply effective techniques on the raw ECG signals to process and decompose it in a simpler manner to obtain more useful information out of signals that can be utilized for more powerful and efficient applications in the near future related to HRV.

  7. The effect of binaural beats on verbal working memory and cortical connectivity

    Science.gov (United States)

    Beauchene, Christine; Abaid, Nicole; Moran, Rosalyn; Diana, Rachel A.; Leonessa, Alexander

    2017-04-01

    Objective. Synchronization in activated regions of cortical networks affect the brain’s frequency response, which has been associated with a wide range of states and abilities, including memory. A non-invasive method for manipulating cortical synchronization is binaural beats. Binaural beats take advantage of the brain’s response to two pure tones, delivered independently to each ear, when those tones have a small frequency mismatch. The mismatch between the tones is interpreted as a beat frequency, which may act to synchronize cortical oscillations. Neural synchrony is particularly important for working memory processes, the system controlling online organization and retention of information for successful goal-directed behavior. Therefore, manipulation of synchrony via binaural beats provides a unique window into working memory and associated connectivity of cortical networks. Approach. In this study, we examined the effects of different acoustic stimulation conditions during an N-back working memory task, and we measured participant response accuracy and cortical network topology via EEG recordings. Six acoustic stimulation conditions were used: None, Pure Tone, Classical Music, 5 Hz binaural beats, 10 Hz binaural beats, and 15 Hz binaural beats. Main results. We determined that listening to 15 Hz binaural beats during an N-Back working memory task increased the individual participant’s accuracy, modulated the cortical frequency response, and changed the cortical network connection strengths during the task. Only the 15 Hz binaural beats produced significant change in relative accuracy compared to the None condition. Significance. Listening to 15 Hz binaural beats during the N-back task activated salient frequency bands and produced networks characterized by higher information transfer as compared to other auditory stimulation conditions.

  8. [Control of tachycardia with intravenous amiodarone in acute left heart failure].

    Science.gov (United States)

    Tomcsányi, J; Arabadzisz, H; Zsoldos, A; Marosi, A; Beck, K

    2001-12-30

    The treatment of atrial tachycardia in critically ill patients can be difficult. Nine cases were presented with atrial tachyarrhythmias (mean heart rate > 130 beats/min) and left heart failure. Congestive heart failure was diagnosed in 6 patients (ejection fraction heart failure in 3 patients (ejection infarction > 55%). The infusion of amiodarone (450 mg over 10 min and 0.5 mg/min after the bolus administration) was associated with a decrease in heart rate 31 beats/min and an increase in systolic blood pressure of 13 mm Hg after one hour. There was only one adverse effect secondary to amiodarone therapy. In this case the sinus rhythm converted within 24 hours but T-waves alternans and short running torsade de pointes ventricular tachycardia was observed and amiodarone therapy was discontinued.

  9. Heart transplantation in adult congenital heart disease.

    Science.gov (United States)

    Burchill, Luke J

    2016-12-01

    Heart failure (HF) in adult congenital heart disease (ACHD) is vastly different to that observed in acquired heart disease. Unlike acquired HF in which pharmacological strategies are the cornerstone for protecting and improving ventricular function, ACHD-related HF relies heavily upon structural and other interventions to achieve these aims. patients with ACHD constitute a small percentage of the total adult heart transplant population (∼3%), although the number of ACHD heart transplant recipients is growing rapidly with a 40% increase over the last two decades. The worldwide experience to date has confirmed heart transplantation as an effective life-extending treatment option in carefully selected patients with ACHD with end-stage cardiac disease. Opportunities for improving outcomes in patients with ACHD-related HF include (i) earlier recognition and referral to centres with combined expertise in ACHD and HF, (ii) increased awareness of arrhythmia and sudden cardiac death risk in this population, (iii) greater collaboration between HF and ACHD specialists at the time of heart transplant assessment, (iv) expert surgical planning to reduce ischaemic time and bleeding risk at the time of transplant, (v) tailored immunosuppression in the post-transplant period and (vi) development and validation of ACHD-specific risk scores to predict mortality and guide patient selection. The purpose of this article is to review current approaches to diagnosing and treating advanced HF in patients with ACHD including indications, contraindications and clinical outcomes after heart transplantation. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

  10. Median maximal heart rate for heart rate calibration in different conditions: laboratory, field and competition.

    Science.gov (United States)

    Boudet, G; Garet, M; Bedu, M; Albuisson, E; Chamoux, A

    2002-05-01

    The objective of this study was to evaluate the variability of maximal heart rate in three different conditions: laboratory tests, field tests, and competitions. Sixteen male endurance volunteers were tested in five exhaustive tests for each condition. All exhaustive events were heart rate monitored (Accurex plus, Polar Electro, Finland) and true maximal heart rates were assessed and compared with each other and with predicted maximal heart rates. Results show that under the three conditions HR(peaks) were not statistically different (p = 0.62, NS, Friedman test). Mean HR(peaks) (SD) were: laboratory = 194.3 (7.8), field = 193.8 (11.8), competition = 192.3 (10.1) beats x min(-1). Conditions for reaching individual heart rate peak were in the laboratory (treadmill VO(2)max protocol) for 5 subjects, in field tests for 7 subjects and in competitions for 6 subjects (two circumstances for two subjects). A large intra-individual variation existed in the three circumstances (+/- 6 beats x min(-1)). Absolute median maximal heart rate was 190.0 bpm (9.32) i.e 7.6 bpm lower than heart rate peak. Both were highly related (rho = 0.89, z = 3.449, p = 0.0006, Spearman test). Median maximal heart rates inter-condition relationship were higher. Median maximal heart rate was more stable and took more information into account than an isolated peak. It gives a central value that minimizes the potential risk of under or over estimation when calibrating exercise intensities with HR.

  11. Visibility graph analysis of heart rate time series and bio-marker of congestive heart failure

    Science.gov (United States)

    Bhaduri, Anirban; Bhaduri, Susmita; Ghosh, Dipak

    2017-09-01

    Study of RR interval time series for Congestive Heart Failure had been an area of study with different methods including non-linear methods. In this article the cardiac dynamics of heart beat are explored in the light of complex network analysis, viz. visibility graph method. Heart beat (RR Interval) time series data taken from Physionet database [46, 47] belonging to two groups of subjects, diseased (congestive heart failure) (29 in number) and normal (54 in number) are analyzed with the technique. The overall results show that a quantitative parameter can significantly differentiate between the diseased subjects and the normal subjects as well as different stages of the disease. Further, the data when split into periods of around 1 hour each and analyzed separately, also shows the same consistent differences. This quantitative parameter obtained using the visibility graph analysis thereby can be used as a potential bio-marker as well as a subsequent alarm generation mechanism for predicting the onset of Congestive Heart Failure.

  12. Biophysical characterization of the underappreciated and important relationship between heart rate variability and heart rate.

    Science.gov (United States)

    Monfredi, Oliver; Lyashkov, Alexey E; Johnsen, Anne-Berit; Inada, Shin; Schneider, Heiko; Wang, Ruoxi; Nirmalan, Mahesh; Wisloff, Ulrik; Maltsev, Victor A; Lakatta, Edward G; Zhang, Henggui; Boyett, Mark R

    2014-12-01

    Heart rate (HR) variability (HRV; beat-to-beat changes in the R-wave to R-wave interval) has attracted considerable attention during the past 30+ years (PubMed currently lists >17 000 publications). Clinically, a decrease in HRV is correlated to higher morbidity and mortality in diverse conditions, from heart disease to fetal distress. It is usually attributed to fluctuation in cardiac autonomic nerve activity. We calculated HRV parameters from a variety of cardiac preparations (including humans, living animals, Langendorff-perfused heart, and single sinoatrial nodal cell) in diverse species, combining this with data from previously published articles. We show that regardless of conditions, there is a universal exponential decay-like relationship between HRV and HR. Using 2 biophysical models, we develop a theory for this and confirm that HRV is primarily dependent on HR and cannot be used in any simple way to assess autonomic nerve activity to the heart. We suggest that the correlation between a change in HRV and altered morbidity and mortality is substantially attributable to the concurrent change in HR. This calls for re-evaluation of the findings from many articles that have not adjusted properly or at all for HR differences when comparing HRV in multiple circumstances. © 2014 American Heart Association, Inc.

  13. Gender- and age-related differences in heart rate dynamics: are women more complex than men?

    Science.gov (United States)

    Ryan, S. M.; Goldberger, A. L.; Pincus, S. M.; Mietus, J.; Lipsitz, L. A.

    1994-01-01

    OBJECTIVES. This study aimed to quantify the complex dynamics of beat-to-beat sinus rhythm heart rate fluctuations and to determine their differences as a function of gender and age. BACKGROUND. Recently, measures of heart rate variability and the nonlinear "complexity" of heart rate dynamics have been used as indicators of cardiovascular health. Because women have lower cardiovascular risk and greater longevity than men, we postulated that there are important gender-related differences in beat-to-beat heart rate dynamics. METHODS. We analyzed heart rate dynamics during 8-min segments of continuous electrocardiographic recording in healthy young (20 to 39 years old), middle-aged (40 to 64 years old) and elderly (65 to 90 years old) men (n = 40) and women (n = 27) while they performed spontaneous and metronomic (15 breaths/min) breathing. Relatively high (0.15 to 0.40 Hz) and low (0.01 to 0.15 Hz) frequency components of heart rate variability were computed using spectral analysis. The overall "complexity" of each heart rate time series was quantified by its approximate entropy, a measure of regularity derived from nonlinear dynamics ("chaos" theory). RESULTS. Mean heart rate did not differ between the age groups or genders. High frequency heart rate power and the high/low frequency power ratio decreased with age in both men and women (p gender-as well as age-related differences in heart rate dynamics. Whether these gender differences are related to lower cardiovascular disease risk and greater longevity in women requires further study.

  14. Estimation of Human Heart Activity Using Ensemble Kalman Filter

    Directory of Open Access Journals (Sweden)

    Pradhnya Arun Priyadarshi

    2017-02-01

    Full Text Available Heart beat measurement techniques come across various challenges. Electrocardiogram (ECG obtained sometimes does not reveal complete information about electrochemical activity of human heart, because of which functioning of heart cannot be studied properly. In this paper Ensemble Kalman Filter (EnKF is used to generate ECG signal efficiently with better accuracy such that the drawbacks of current techniques are eliminated. Here EnKF is applied to second order mathematical model of human heart, input applied to this mathematical model is a pacemaker signal. The initial values of heart muscle movements and electrochemical activity as a discrete data set are used and prediction steps are commenced. EnKF uses ensemble integration technique to model error statistics which helps obtaining more precise output. The results are obtained with negligible sum squared error, therefore the ECG obtained using EnKF can diagnose the disease related to heart with better accuracy.

  15. Asymmetric Dimethylarginine Blocks Nitric Oxide-Mediated Alcohol-Stimulated Cilia Beating

    Directory of Open Access Journals (Sweden)

    T. A. Wyatt

    2013-01-01

    Full Text Available The airway epithelium is exposed to alcohol during drinking through direct exhalation of volatized ethanol from the bronchial circulation. Alcohol exposure leads to a rapid increase in the cilia beat frequency (CBF of bronchial epithelial cells followed by a chronic desensitization of cilia stimulatory responses. This effect is governed in part by the nitric oxide regulation of cyclic guanosine and adenosine monophosphate-dependent protein kinases (PKG and PKA and is not fully understood. Asymmetric dimethylarginine (ADMA, an endogenous inhibitor of nitric oxide synthase, is implicated in the pathogenesis of several pulmonary disorders. We hypothesized that the inhibition of nitric oxide synthase by ADMA blocks alcohol-stimulated increases in CBF. To test this hypothesis, ciliated primary bovine bronchial epithelial cells (BBEC were preincubated with ADMA (100 µM and stimulated with 100 mM ethanol. CBF was measured and PKA assayed. By 1 hr, ethanol activated PKA, resulting in elevated CBF. Both alcohol-induced PKA activation and CBF were inhibited in the presence of ADMA. ADMA alone had no effect on PKA activity or CBF. Using a mouse model overexpressing the ADMA-degrading enzyme, dimethylarginine dimethylaminohydrolase (DDAH, we examined PKA and CBF in precision-cut mouse lung slices. Alcohol-stimulated increases in lung slice PKA and CBF were temporally enhanced in the DDAH mice versus control mice.

  16. Diminution of Heart Rate Variability in Bipolar Depression

    Directory of Open Access Journals (Sweden)

    Brandon Hage

    2017-12-01

    Full Text Available Autonomic nervous system (ANS dysregulation in depression is associated with symptoms associated with the ANS. The beat-to-beat pattern of heart rate defined as heart rate variability (HRV provides a noninvasive portal to ANS function and has been proposed to represent a means of quantifying resting vagal tone. We quantified HRV in bipolar depressed (BDD patients as a measure of ANS dysregulation seeking to establish HRV as a potential diagnostic and prognostic biomarker for treatment outcome. Forty-seven BDD patients were enrolled. They were randomized to receive either escitalopram–celecoxib or escitalopram-placebo over 8 weeks in a double-blind study design. Thirty-five patients completed the HRV studies. Thirty-six healthy subjects served as controls. HRV was assessed at pretreatment and end of study and compared with that of controls. HRV was quantified and corrected for artifacts using an algorithm that incorporates time and frequency domains to address non-stationarity of the beat-to-beat heart rate pattern. Baseline high frequency-HRV (i.e., respiratory sinus arrhythmia was lower in BDD patients than controls, although the difference did not reach significance. Baseline low-frequency HRV was significantly lower in BDD patients (ln4.20 than controls (ln = 5.50 (p < 0.01. Baseline heart period was significantly shorter (i.e., faster heart rate in BDD patients than controls. No significant change in HRV parameters were detected over the course of the study with either treatment. These findings suggest that components of HRV may be diminished in BDD patients.

  17. Effects of single cycle binaural beat duration on auditory evoked potentials.

    Science.gov (United States)

    Mihajloski, Todor; Bohorquez, Jorge; Özdamar, Özcan

    2014-01-01

    Binaural beat (BB) illusions are experienced as continuous central pulsations when two sounds with slightly different frequencies are delivered to each ear. It has been shown that steady-state auditory evoked potentials (AEPs) to BBs can be captured and investigated. The authors recently developed a new method of evoking transient AEPs to binaural beats using frequency modulated stimuli. This methodology was able to create single BBs in predetermined intervals with varying carrier frequencies. This study examines the effects of the BB duration and the frequency modulating component of the stimulus on the binaural beats and their evoked potentials. Normal hearing subjects were tested with a set of four durations (25, 50, 100, and 200 ms) with two stimulation configurations, binaural dichotic (binaural beats) and diotic (frequency modulation). The results obtained from the study showed that out of the given durations, the 100 ms beat, was capable of evoking the largest amplitude responses. The frequency modulation effect showed a decrease in peak amplitudes with increasing beat duration until their complete disappearance at 200 ms. Even though, at 200 ms, the frequency modulation effects were not present, the binaural beats were still perceived and captured as evoked potentials.

  18. The effect of beat frequency on eye movements during free viewing.

    Science.gov (United States)

    Maróti, Emese; Knakker, Balázs; Vidnyánszky, Zoltán; Weiss, Béla

    2017-02-01

    External periodic stimuli entrain brain oscillations and affect perception and attention. It has been shown that background music can change oculomotor behavior and facilitate detection of visual objects occurring on the musical beat. However, whether musical beats in different tempi modulate information sampling differently during natural viewing remains to be explored. Here we addressed this question by investigating how listening to naturalistic drum grooves in two different tempi affects eye movements of participants viewing natural scenes on a computer screen. We found that the beat frequency of the drum grooves modulated the rate of eye movements: fixation durations were increased at the lower beat frequency (1.7Hz) as compared to the higher beat frequency (2.4Hz) and no music conditions. Correspondingly, estimated visual sampling frequency decreased as fixation durations increased with lower beat frequency. These results imply that slow musical beats can retard sampling of visual information during natural viewing by increasing fixation durations. Copyright © 2016 Elsevier Ltd. All rights reserved.

  19. Adapting workload improves the measurement of heart rate recovery.

    Science.gov (United States)

    Lamberts, R P; Maskell, S; Borresen, J; Lambert, M I

    2011-09-01

    Heart rate after a standardized test varies with a change in training status, possibly compromising the accuracy of measuring changes in heart rate recovery (HRR). The aim of this study was to determine if a change in the exercise intensity would result in a change in heart rate recovery and/or the accuracy of the heart rate recovery measurement. 31 subjects performed 4 submaximal running tests (HIMS). Based on the heart rate after the first HIMS, subjects either completed 4 identical HIMS (SAME (n=9)), 2 standard and 2 faster HIMS (FASTER (n=10)) or 2 standard and 2 slower HIMS (SLOWER (n=12)). Although no changes in heart rate recovery were found when the HIMS protocol was adapted, lower coefficients of variation (CV) and typical errors of measurement (TEM) were found in the SLOWER (CV: 11 ± 7 to 5 ± 3% ( P=0.025)), TEM: 6 to 3 beats and FASTER group (CV: 11 ± 7 to 4 ± 3% ( P=0.048), TEM: 7 to 3 beats). To ensure the highest level of sensitivity in detecting meaningful changes in HRR over time, submaximal testing protocols should target exercise intensities ranging in-between 86-93% of heart rate maximum. © Georg Thieme Verlag KG Stuttgart · New York.

  20. Tachyphylaxis of human forearm vascular responses does not occur rapidly after exposure to isoproterenol.

    Science.gov (United States)

    Stein, C M; Nelson, R; Deegan, R; He, H; Inagami, T; Frazer, M; Badr, K F; Wood, M; Wood, A J

    1995-06-01

    In vitro and limited in vivo data suggest that rapid desensitization of beta-adrenoceptor responses occurs after exposure to agonist. Tachyphylaxis to a beta-adrenoceptor agonist would represent a potentially important mechanism for the short-term regulation of vascular tone. The effects of a 4-hour infusion of 400 ng/min intra-arterial isoproterenol on forearm blood flow and presynaptic beta-adrenoceptor-mediated norepinephrine release were determined in eight healthy volunteers. Intra-arterial isoproterenol at 400 ng/min resulted in a significant increase in forearm blood flow in all eight subjects at all time points, with no evidence of tachyphylaxis. In fact, forearm blood flow after 4 hours of the isoproterenol infusion (22.8 +/- 3.3 mL/100 mL per minute) was significantly greater than after 7 minutes (14.6 +/- 2.8 mL/100 mL per minute), 15 minutes (15.4 +/- 2.4 mL/100 mL per minute), and 30 minutes (17.4 +/- 3.0 mL/100 mL per minute) of the infusion (P < .05). Similarly, presynaptic beta-adrenoceptor responses showed no evidence of tachyphylaxis, so forearm norepinephrine spillover values after 7 minutes (6.6 +/- 0.94 ng/min), 15 minutes (7.6 +/- 1.5 ng/min), and 4 hours (8.8 +/- 1.1 ng/min) of isoproterenol infusion were increased and similar. Minimal systemic effects were observed, and there was no evidence of tolerance, there being no difference in heart rate after 7 minutes (70.7 +/- 2.7 beats per minute) and 4 hours (72.2 +/- 3.6 beats per minute) of isoproterenol infusion.(ABSTRACT TRUNCATED AT 250 WORDS)

  1. The evolutionary neuroscience of musical beat perception: the Action Simulation for Auditory Prediction (ASAP) hypothesis

    Science.gov (United States)

    Patel, Aniruddh D.; Iversen, John R.

    2013-01-01

    Every human culture has some form of music with a beat: a perceived periodic pulse that structures the perception of musical rhythm and which serves as a framework for synchronized movement to music. What are the neural mechanisms of musical beat perception, and how did they evolve? One view, which dates back to Darwin and implicitly informs some current models of beat perception, is that the relevant neural mechanisms are relatively general and are widespread among animal species. On the basis of recent neural and cross-species data on musical beat processing, this paper argues for a different view. Here we argue that beat perception is a complex brain function involving temporally-precise communication between auditory regions and motor planning regions of the cortex (even in the absence of overt movement). More specifically, we propose that simulation of periodic movement in motor planning regions provides a neural signal that helps the auditory system predict the timing of upcoming beats. This “action simulation for auditory prediction” (ASAP) hypothesis leads to testable predictions. We further suggest that ASAP relies on dorsal auditory pathway connections between auditory regions and motor planning regions via the parietal cortex, and suggest that these connections may be stronger in humans than in non-human primates due to the evolution of vocal learning in our lineage. This suggestion motivates cross-species research to determine which species are capable of human-like beat perception, i.e., beat perception that involves accurate temporal prediction of beat times across a fairly broad range of tempi. PMID:24860439

  2. The evolutionary neuroscience of musical beat perception: the Action Simulation for Auditory Prediction (ASAP hypothesis.

    Directory of Open Access Journals (Sweden)

    Aniruddh D. Patel

    2014-05-01

    Full Text Available Every human culture has some form of music with a beat: a perceived periodic pulse that structures the perception of musical rhythm and which serves as a framework for synchronized movement to music. What are the neural mechanisms of musical beat perception, and how did they evolve? One view, which dates back to Darwin and implicitly informs some current models of beat perception, is that the relevant neural mechanisms are relatively general and are widespread among animal species. On the basis of recent neural and cross-species data on musical beat processing, this paper argues for a different view. Here we argue that beat perception is a complex brain function involving temporally-precise communication between auditory regions and motor planning regions of the cortex (even in the absence of overt movement. More specifically, we propose that simulation of periodic movement in motor planning regions provides a neural signal that helps the auditory system predict the timing of upcoming beats. This action simulation for auditory prediction (ASAP hypothesis leads to testable predictions. We further suggest that ASAP relies on dorsal auditory pathway connections between auditory regions and motor planning regions via the parietal cortex, and suggest that these connections may be stronger in humans than in nonhuman primates due to the evolution of vocal learning in our lineage. This suggestion motivates cross-species research to determine which species are capable of human-like beat perception, i.e., beat perception that involves accurate temporal prediction of beat times across a fairly broad range of tempi.

  3. Angiotensin-converting enzyme and matrix metalloproteinase inhibition with developing heart failure: comparative effects on left ventricular function and geometry

    Science.gov (United States)

    McElmurray, J. H. 3rd; Mukherjee, R.; New, R. B.; Sampson, A. C.; King, M. K.; Hendrick, J. W.; Goldberg, A.; Peterson, T. J.; Hallak, H.; Zile, M. R.; hide

    1999-01-01

    The progression of congestive heart failure (CHF) is left ventricular (LV) myocardial remodeling. The matrix metalloproteinases (MMPs) contribute to tissue remodeling and therefore MMP inhibition may serve as a useful therapeutic target in CHF. Angiotensin converting enzyme (ACE) inhibition favorably affects LV myocardial remodeling in CHF. This study examined the effects of specific MMP inhibition, ACE inhibition, and combined treatment on LV systolic and diastolic function in a model of CHF. Pigs were randomly assigned to five groups: 1) rapid atrial pacing (240 beats/min) for 3 weeks (n = 8); 2) ACE inhibition (fosinopril, 2.5 mg/kg b.i.d. orally) and rapid pacing (n = 8); 3) MMP inhibition (PD166793 2 mg/kg/day p.o.) and rapid pacing (n = 8); 4) combined ACE and MMP inhibition (2.5 mg/kg b.i.d. and 2 mg/kg/day, respectively) and rapid pacing (n = 8); and 5) controls (n = 9). LV peak wall stress increased by 2-fold with rapid pacing and was reduced in all treatment groups. LV fractional shortening fell by nearly 2-fold with rapid pacing and increased in all treatment groups. The circumferential fiber shortening-systolic stress relation was reduced with rapid pacing and increased in the ACE inhibition and combination groups. LV myocardial stiffness constant was unchanged in the rapid pacing group, increased nearly 2-fold in the MMP inhibition group, and was normalized in the ACE inhibition and combination treatment groups. Increased MMP activation contributes to the LV dilation and increased wall stress with pacing CHF and a contributory downstream mechanism of ACE inhibition is an effect on MMP activity.

  4. Heart Rate Variability Monitoring during Sleep Based on Capacitively Coupled Textile Electrodes on a Bed

    Directory of Open Access Journals (Sweden)

    Hong Ji Lee

    2015-05-01

    Full Text Available In this study, we developed and tested a capacitively coupled electrocardiogram (ECG measurement system using conductive textiles on a bed, for long-term healthcare monitoring. The system, which was designed to measure ECG in a bed with no constraints of sleep position and posture, included a foam layer to increase the contact region with the curvature of the body and a cover to ensure durability and easy installation. Nine healthy subjects participated in the experiment during polysomnography (PSG, and the heart rate (HR coverage and heart rate variability (HRV parameters were analyzed to evaluate the system. The experimental results showed that the mean of R-peak coverage was 98.0% (95.5%–99.7%, and the normalized errors of HRV time and spectral measures between the Ag/AgCl system and our system ranged from 0.15% to 4.20%. The root mean square errors for inter-beat (RR intervals and HR were 1.36 ms and 0.09 bpm, respectively. We also showed the potential of our developed system for rapid eye movement (REM sleep and wake detection as well as for recording of abnormal states.

  5. Disentangling beat perception from sequential learning and examining the influence of attention and musical abilities on ERP responses to rhythm.

    Science.gov (United States)

    Bouwer, Fleur L; Werner, Carola M; Knetemann, Myrthe; Honing, Henkjan

    2016-05-01

    Beat perception is the ability to perceive temporal regularity in musical rhythm. When a beat is perceived, predictions about upcoming events can be generated. These predictions can influence processing of subsequent rhythmic events. However, statistical learning of the order of sounds in a sequence can also affect processing of rhythmic events and must be differentiated from beat perception. In the current study, using EEG, we examined the effects of attention and musical abilities on beat perception. To ensure we measured beat perception and not absolute perception of temporal intervals, we used alternating loud and soft tones to create a rhythm with two hierarchical metrical levels. To control for sequential learning of the order of the different sounds, we used temporally regular (isochronous) and jittered rhythmic sequences. The order of sounds was identical in both conditions, but only the regular condition allowed for the perception of a beat. Unexpected intensity decrements were introduced on the beat and offbeat. In the regular condition, both beat perception and sequential learning were expected to enhance detection of these deviants on the beat. In the jittered condition, only sequential learning was expected to affect processing of the deviants. ERP responses to deviants were larger on the beat than offbeat in both conditions. Importantly, this difference was larger in the regular condition than in the jittered condition, suggesting that beat perception influenced responses to rhythmic events in addition to sequential learning. The influence of beat perception was present both with and without attention directed at the rhythm. Moreover, beat perception as measured with ERPs correlated with musical abilities, but only when attention was directed at the stimuli. Our study shows that beat perception is possible when attention is not directed at a rhythm. In addition, our results suggest that attention may mediate the influence of musical abilities on beat

  6. Beta-Band Oscillations Represent Auditory Beat and Its Metrical Hierarchy in Perception and Imagery.

    Science.gov (United States)

    Fujioka, Takako; Ross, Bernhard; Trainor, Laurel J

    2015-11-11

    Dancing to music involves synchronized movements, which can be at the basic beat level or higher hierarchical metrical levels, as in a march (groups of two basic beats, one-two-one-two …) or waltz (groups of three basic beats, one-two-three-one-two-three …). Our previous human magnetoencephalography studies revealed that the subjective sense of meter influences auditory evoked responses phase locked to the stimulus. Moreover, the timing of metronome clicks was represented in periodic modulation of induced (non-phase locked) β-band (13-30 Hz) oscillation in bilateral auditory and sensorimotor cortices. Here, we further examine whether acoustically accented and subjectively imagined metric processing in march and waltz contexts during listening to isochronous beats were reflected in neuromagnetic β-band activity recorded from young adult musicians. First, we replicated previous findings of beat-related β-power decrease at 200 ms after the beat followed by a predictive increase toward the onset of the next beat. Second, we showed that the β decrease was significantly influenced by the metrical structure, as reflected by differences across beat type for both perception and imagery conditions. Specifically, the β-power decrease associated with imagined downbeats (the count "one") was larger than that for both the upbeat (preceding the count "one") in the march, and for the middle beat in the waltz. Moreover, beamformer source analysis for the whole brain volume revealed that the metric contrasts involved auditory and sensorimotor cortices; frontal, parietal, and inferior temporal lobes; and cerebellum. We suggest that the observed β-band activities reflect a translation of timing information to auditory-motor coordination. With magnetoencephalography, we examined β-band oscillatory activities around 20 Hz while participants listened to metronome beats and imagined musical meters such as a march and waltz. We demonstrated that β-band event

  7. Dynamic heart phantom with functional mitral and aortic valves

    Science.gov (United States)

    Vannelli, Claire; Moore, John; McLeod, Jonathan; Ceh, Dennis; Peters, Terry

    2015-03-01

    Cardiac valvular stenosis, prolapse and regurgitation are increasingly common conditions, particularly in an elderly population with limited potential for on-pump cardiac surgery. NeoChord©, MitraClipand numerous stent-based transcatheter aortic valve implantation (TAVI) devices provide an alternative to intrusive cardiac operations; performed while the heart is beating, these procedures require surgeons and cardiologists to learn new image-guidance based techniques. Developing these visual aids and protocols is a challenging task that benefits from sophisticated simulators. Existing models lack features needed to simulate off-pump valvular procedures: functional, dynamic valves, apical and vascular access, and user flexibility for different activation patterns such as variable heart rates and rapid pacing. We present a left ventricle phantom with these characteristics. The phantom can be used to simulate valvular repair and replacement procedures with magnetic tracking, augmented reality, fluoroscopy and ultrasound guidance. This tool serves as a platform to develop image-guidance and image processing techniques required for a range of minimally invasive cardiac interventions. The phantom mimics in vivo mitral and aortic valve motion, permitting realistic ultrasound images of these components to be acquired. It also has a physiological realistic left ventricular ejection fraction of 50%. Given its realistic imaging properties and non-biodegradable composition—silicone for tissue, water for blood—the system promises to reduce the number of animal trials required to develop image guidance applications for valvular repair and replacement. The phantom has been used in validation studies for both TAVI image-guidance techniques1, and image-based mitral valve tracking algorithms2.

  8. Enlarged Heart

    Science.gov (United States)

    ... the valves are damaged by conditions such as rheumatic fever, a heart defect, infections (infectious endocarditis), connective tissue disorders, certain medications or radiation treatments for cancer, your heart may ...

  9. Heart Truth

    Science.gov (United States)

    ... health! Get a free badge or banner to post to your website or blog. Are you at risk for heart disease? Here's how to find out . Planning to use The Heart Truth logo? Check out our logo guidelines and downloads. ...

  10. Heart Failure

    Science.gov (United States)

    ... heart failure due to systolic dysfunction. http://www.uptodate.com/home. Accessed Sept. 26, 2014. Colucci WS. ... patient with heart failure or cardiomyopathy. http://www.uptodate.com/home. Accessed Sept. 26, 2014. Colucci WS. ...

  11. Rapid 3D imaging of the lower airway by MRI in patients with congenital heart disease: A retrospective comparison of delayed volume interpolated breath-hold examination (VIBE) to turbo spin echo (TSE).

    Science.gov (United States)

    Goot, Benjamin H; Patel, Sonali; Fonseca, Brian

    2017-01-01

    When imaging the lower airway by MRI, the traditional technique turbo spin echo (TSE) results in high quality 2D images, however planning and acquisition times are lengthy. An alternative, delayed volume interpolated breath-holds examination (VIBE), is a 3D gradient echo technique that produces high spatial resolution imaging of the airway in one breath-hold. The objective of this study is to retrospectively evaluate the accuracy of lower airway measurements obtained by delayed VIBE when compared to TSE. Patients with congenital heart disease who underwent a cardiac MRI (CMR) that included a delayed VIBE sequence from 5/2008 to 9/2013 were included. Standard TSE imaging was performed and delayed VIBE was acquired 5 min after gadolinium contrast administration. Airway measurements were made on both sequences by two observers in a blinded fashion to the other observer and other technique. Intraclass correlations (ICC) were calculated to assess for agreement between both techniques and the observers. 29 studies met inclusion criteria with a mean patient age of 8.8 years (2 months to 63 years) and mean patient weight of 30.2 kg (3.5-110). All delayed VIBE and TSE sequences were found to be of diagnostic quality. Mean acquisition time was shorter for the delayed VIBE (13.1 seconds) than TSE (949.9 seconds). Overall there was very good agreement between the delayed VIBE and TSE measurements for both observers (ICC 0.78-0.94) with the exception of the distal right bronchus (ICC 0.67) The interobserver agreement was also excellent for both TSE (ICC 0.78-0.96) and VIBE (ICC 0.85-0.96). Delayed VIBE is rapid and at least as accurate as the alternative TSE imaging for assessment of the lower airway by MRI across a wide spectrum of patients. © 2016 Wiley Periodicals, Inc.

  12. Exploiting Concurrent Wake-Up Transmissions Using Beat Frequencies

    Directory of Open Access Journals (Sweden)

    Timo Kumberg

    2017-07-01

    Full Text Available Wake-up receivers are the natural choice for wireless sensor networks because of their ultra-low power consumption and their ability to provide communications on demand. A downside of ultra-low power wake-up receivers is their low sensitivity caused by the passive demodulation of the carrier signal. In this article, we present a novel communication scheme by exploiting purposefully-interfering out-of-tune signals of two or more wireless sensor nodes, which produce the wake-up signal as the beat frequency of superposed carriers. Additionally, we introduce a communication algorithm and a flooding protocol based on this approach. Our experiments show that our approach increases the received signal strength up to 3 dB, improving communication robustness and reliability. Furthermore, we demonstrate the feasibility of our newly-developed protocols by means of an outdoor experiment and an indoor setup consisting of several nodes. The flooding algorithm achieves almost a 100% wake-up rate in less than 20 ms.

  13. Automatic analysis of ciliary beat frequency using optical flow

    Science.gov (United States)

    Figl, Michael; Lechner, Manuel; Werther, Tobias; Horak, Fritz; Hummel, Johann; Birkfellner, Wolfgang

    2012-02-01

    Ciliary beat frequency (CBF) can be a useful parameter for diagnosis of several diseases, as e.g. primary ciliary dyskinesia. (PCD). CBF computation is usually done using manual evaluation of high speed video sequences, a tedious, observer dependent, and not very accurate procedure. We used the OpenCV's pyramidal implementation of the Lukas-Kanade algorithm for optical flow computation and applied this to certain objects to follow the movements. The objects were chosen by their contrast applying the corner detection by Shi and Tomasi. Discrimination between background/noise and cilia by a frequency histogram allowed to compute the CBF. Frequency analysis was done using the Fourier transform in matlab. The correct number of Fourier summands was found by the slope in an approximation curve. The method showed to be usable to distinguish between healthy and diseased samples. However there remain difficulties in automatically identifying the cilia, and also in finding enough high contrast cilia in the image. Furthermore the some of the higher contrast cilia are lost (and sometimes found) by the method, an easy way to distinguish the correct sub-path of a point's path have yet to be found in the case where the slope methods doesn't work.

  14. A question of getting the right BEAT? Life cycle assesment

    Energy Technology Data Exchange (ETDEWEB)

    Zeiler, W. [Kropman Building Services, Nijmegen (Netherlands); Van Deursen, J.T.; Boxem, G. [Technische Universiteit Eindhoven, Eindhoven (Netherlands)

    2009-06-15

    There is a strong need for more efficient and more sustainable buildings. At present it is difficult in the conceptual design phase to define the life cycle performance of buildings in terms of efficiency and sustainability in an objective way. Goal of this project is to examine and to understand differences between different building rating systems and between these systems and the necessary design support. What makes a good building is subject to multiple interpretations based on the different background, training and experiences of the people who answer the question about how good a building is. What is needed is a new integral design approach which enables to integrate the different aspects of sustainable buildings in a supportive framework during the design process. Especially, the focus is on Multi Criteria Decision making within the design process and how to support this, so that the decisions about fulfilling sustainable aspects in the design are made transparent for all stakeholders within the design process. BEAT in the title stands for Building Environmental Assessment Tools.

  15. Heart Failure

    DEFF Research Database (Denmark)

    Jorsal, Anders; Wiggers, Henrik; McMurray, John J V

    2018-01-01

    This article briefly discusses the epidemiology of heart failure and diabetes and summarizes the key findings from the recent cardiovascular outcome trials in patients with type 2 diabetes, with a focus on heart failure as an endpoint.......This article briefly discusses the epidemiology of heart failure and diabetes and summarizes the key findings from the recent cardiovascular outcome trials in patients with type 2 diabetes, with a focus on heart failure as an endpoint....

  16. A novel technique for fetal heart rate estimation from Doppler ultrasound signal

    Directory of Open Access Journals (Sweden)

    Jezewski Janusz

    2011-10-01

    Full Text Available Abstract Background The currently used fetal monitoring instrumentation that is based on Doppler ultrasound technique provides the fetal heart rate (FHR signal with limited accuracy. It is particularly noticeable as significant decrease of clinically important feature - the variability of FHR signal. The aim of our work was to develop a novel efficient technique for processing of the ultrasound signal, which could estimate the cardiac cycle duration with accuracy comparable to a direct electrocardiography. Methods We have proposed a new technique which provides the true beat-to-beat values of the FHR signal through multiple measurement of a given cardiac cycle in the ultrasound signal. The method consists in three steps: the dynamic adjustment of autocorrelation window, the adaptive autocorrelation peak detection and determination of beat-to-beat intervals. The estimated fetal heart rate values and calculated indices describing variability of FHR, were compared to the reference data obtained from the direct fetal electrocardiogram, as well as to another method for FHR estimation. Results The results revealed that our method increases the accuracy in comparison to currently used fetal monitoring instrumentation, and thus enables to calculate reliable parameters describing the variability of FHR. Relating these results to the other method for FHR estimation we showed that in our approach a much lower number of measured cardiac cycles was rejected as being invalid. Conclusions The proposed method for fetal heart rate determination on a beat-to-beat basis offers a high accuracy of the heart interval measurement enabling reliable quantitative assessment of the FHR variability, at the same time reducing the number of invalid cardiac cycle measurements.

  17. Short-term beat-to-beat variability of the QT interval is increased and correlates with parameters of left ventricular hypertrophy in patients with hypertrophic cardiomyopathy.

    Science.gov (United States)

    Orosz, Andrea; Baczkó, István; Nagy, Viktória; Gavallér, Henriette; Csanády, Miklós; Forster, Tamás; Papp, Julius Gy; Varró, András; Lengyel, Csaba; Sepp, Róbert

    2015-09-01

    Stratification models for the prediction of sudden cardiac death (SCD) are inappropriate in patients with hypertrophic cardiomyopathy (HCM). We investigated conventional electrocardiogram (ECG) repolarization parameters and the beat-to-beat short-term QT interval variability (QT-STV), a new parameter of proarrhythmic risk, in 37 patients with HCM (21 males, average age 48 ± 15 years). Resting ECGs were recorded for 5 min and the frequency corrected QT interval (QTc), QT dispersion (QTd), beat-to-beat short-term variability of QT interval (QT-STV), and the duration of terminal part of T waves (Tpeak-Tend) were calculated. While all repolarization parameters were significantly increased in patients with HCM compared with the controls (QTc, 488 ± 61 vs. 434 ± 23 ms, p < 0.0001; QT-STV, 4.5 ± 2 vs. 3.2 ± 1 ms, p = 0.0002; Tpeak-Tend duration, 107 ± 27 vs. 91 ± 10 ms, p = 0.0015; QTd, 47 ± 17 vs. 34 ± 9 ms, p = 0.0002), QT-STV had the highest relative increase (+41%). QT-STV also showed the best correlation with indices of left ventricular (LV) hypertrophy, i.e., maximal LV wall thickness normalized for body surface area (BSA; r = 0.461, p = 0.004) or LV mass (determined by cardiac magnetic resonance imaging) normalized for BSA (r = 0.455, p = 0.015). In summary, beat-to-beat QT-STV showed the most marked increase in patients with HCM and may represent a novel marker that merits further testing for increased SCD risk in HCM.

  18. Heart Rate Variability - A Historical Perspective

    Directory of Open Access Journals (Sweden)

    George E Billman

    2011-11-01

    Full Text Available Heart rate variability (HRV, the beat-to-beat variation in either heart rate or the duration of the R-R interval – the heart period, has become a popular clinical and investigational tool. The temporal fluctuations in heart rate exhibit a marked synchrony with respiration (increasing during inspiration and decreasing during expiration – the so called respiratory sinus arrhythmia, RSA and are widely believed to reflect changes in cardiac autonomic regulation. Although the exact contributions of the parasympathetic and the sympathetic divisions of the autonomic nervous system to this variability are controversial and remain the subject of active investigation and debate, a number of time and frequency domain techniques have been developed to provide insight into cardiac autonomic regulation in both health and disease. It is the purpose of this essay to provide an historical overview of the evolution in the concept of heart rate variability. Briefly, pulse rate was first measured by ancient Greek physicians and scientists. However, it was not until the invention of the Physician’s Pulse Watch (a watch with a second hand that could be stopped in 1707 that changes in pulse rate could be accurately assessed. The Rev. Stephen Hales (1733 was the first to note that pulse varied with respiration and in 1847 Carl Ludwig was the first to record RSA. With the measurement of the ECG (1895 and advent of digital signal processing techniques in the 1960’s, investigation of HRV and its relationship to health and disease has exploded. This essay will conclude with a brief description of time domain, frequency domain, and non-linear dynamic analysis techniques (and their limitations that are commonly used to measure heart rate variability.

  19. The Power of Auditory-Motor Synchronization in Sports: Enhancing Running Performance by Coupling Cadence with the Right Beats

    Science.gov (United States)

    Bood, Robert Jan; Nijssen, Marijn; van der Kamp, John; Roerdink, Melvyn

    2013-01-01

    Acoustic stimuli, like music and metronomes, are often used in sports. Adjusting movement tempo to acoustic stimuli (i.e., auditory-motor synchronization) may be beneficial for sports performance. However, music also possesses motivational qualities that may further enhance performance. Our objective was to examine the relative effects of auditory-motor synchronization and the motivational impact of acoustic stimuli on running performance. To this end, 19 participants ran to exhaustion on a treadmill in 1) a control condition without acoustic stimuli, 2) a metronome condition with a sequence of beeps matching participants’ cadence (synchronization), and 3) a music condition with synchronous motivational music matched to participants’ cadence (synchronization+motivation). Conditions were counterbalanced and measurements were taken on separate days. As expected, time to exhaustion was significantly longer with acoustic stimuli than without. Unexpectedly, however, time to exhaustion did not differ between metronome and motivational music conditions, despite differences in motivational quality. Motivational music slightly reduced perceived exertion of sub-maximal running intensity and heart rates of (near-)maximal running intensity. The beat of the stimuli –which was most salient during the metronome condition– helped runners to maintain a consistent pace by coupling cadence to the prescribed tempo. Thus, acoustic stimuli may have enhanced running performance because runners worked harder as a result of motivational aspects (most pronounced with motivational music) and more efficiently as a result of auditory-motor synchronization (most notable with metronome beeps). These findings imply that running to motivational music with a very prominent and consistent beat matched to the runner’s cadence will likely yield optimal effects because it helps to elevate physiological effort at a high perceived exertion, whereas the consistent and correct cadence induced by

  20. The power of auditory-motor synchronization in sports: enhancing running performance by coupling cadence with the right beats.

    Science.gov (United States)

    Bood, Robert Jan; Nijssen, Marijn; van der Kamp, John; Roerdink, Melvyn

    2013-01-01

    Acoustic stimuli, like music and metronomes, are often used in sports. Adjusting movement tempo to acoustic stimuli (i.e., auditory-motor synchronization) may be beneficial for sports performance. However, music also possesses motivational qualities that may further enhance performance. Our objective was to examine the relative effects of auditory-motor synchronization and the motivational impact of acoustic stimuli on running performance. To this end, 19 participants ran to exhaustion on a treadmill in 1) a control condition without acoustic stimuli, 2) a metronome condition with a sequence of beeps matching participants' cadence (synchronization), and 3) a music condition with synchronous motivational music matched to participants' cadence (synchronization+motivation). Conditions were counterbalanced and measurements were taken on separate days. As expected, time to exhaustion was significantly longer with acoustic stimuli than without. Unexpectedly, however, time to exhaustion did not differ between metronome and motivational music conditions, despite differences in motivational quality. Motivational music slightly reduced perceived exertion of sub-maximal running intensity and heart rates of (near-)maximal running intensity. The beat of the stimuli -which was most salient during the metronome condition- helped runners to maintain a consistent pace by coupling cadence to the prescribed tempo. Thus, acoustic stimuli may have enhanced running performance because runners worked harder as a result of motivational aspects (most pronounced with motivational music) and more efficiently as a result of auditory-motor synchronization (most notable with metronome beeps). These findings imply that running to motivational music with a very prominent and consistent beat matched to the runner's cadence will likely yield optimal effects because it helps to elevate physiological effort at a high perceived exertion, whereas the consistent and correct cadence induced by auditory

  1. The power of auditory-motor synchronization in sports: enhancing running performance by coupling cadence with the right beats.

    Directory of Open Access Journals (Sweden)

    Robert Jan Bood

    Full Text Available Acoustic stimuli, like music and metronomes, are often used in sports. Adjusting movement tempo to acoustic stimuli (i.e., auditory-motor synchronization may be beneficial for sports performance. However, music also possesses motivational qualities that may further enhance performance. Our objective was to examine the relative effects of auditory-motor synchronization and the motivational impact of acoustic stimuli on running performance. To this end, 19 participants ran to exhaustion on a treadmill in 1 a control condition without acoustic stimuli, 2 a metronome condition with a sequence of beeps matching participants' cadence (synchronization, and 3 a music condition with synchronous motivational music matched to participants' cadence (synchronization+motivation. Conditions were counterbalanced and measurements were taken on separate days. As expected, time to exhaustion was significantly longer with acoustic stimuli than without. Unexpectedly, however, time to exhaustion did not differ between metronome and motivational music conditions, despite differences in motivational quality. Motivational music slightly reduced perceived exertion of sub-maximal running intensity and heart rates of (near-maximal running intensity. The beat of the stimuli -which was most salient during the metronome condition- helped runners to maintain a consistent pace by coupling cadence to the prescribed tempo. Thus, acoustic stimuli may have enhanced running performance because runners worked harder as a result of motivational aspects (most pronounced with motivational music and more efficiently as a result of auditory-motor synchronization (most notable with metronome beeps. These findings imply that running to motivational music with a very prominent and consistent beat matched to the runner's cadence will likely yield optimal effects because it helps to elevate physiological effort at a high perceived exertion, whereas the consistent and correct cadence induced by

  2. “Would you like to meet the secret Beat?” – Tram Combs and a Beat poetry less celebrated

    DEFF Research Database (Denmark)

    Sørensen, Bent

    directly at Gorm, and asked: “Would you like to meet the secret Beat, then?” The old gentleman proceeded to introduce himself as Tram Combs, poet, bookseller, nude model and gay man about town, and for the next few days he took Gorm to art museums, gallery openings and story-telling sessions in his...... of the poetry of Tram Combs, “the secret Beat”, whose 1957 collection Pilgrim’s Terrace contained forewords by both William Carlos Williams and Kenneth Rexroth, and whose collaborators included Allen Ginsberg – yet whose name is persistently left out of the Beat canon. One wonders why, when he is an example...

  3. High-Frequency Binaural Beats Increase Cognitive Flexibility: Evidence from Dual-Task Crosstalk

    National Research Council Canada - National Science Library

    Hommel, Bernhard; Sellaro, Roberta; Fischer, Rico; Borg, Saskia; Colzato, Lorenza S

    2016-01-01

    ...) or flexibility (by dampening competition and biasing). We investigated whether high-frequency binaural beats, an auditory illusion suspected to act as a cognitive enhancer, have an impact on cognitive-control configuration...

  4. American Idol's Randy Jackson He doesn't miss a beat controlling his diabetes

    Science.gov (United States)

    ... Home Current Issue Past Issues Special Section American Idol's Randy Jackson Past Issues / Winter 2008 Table of ... beat controlling his diabetes. Musician, producer, and American Idol judge Randy Jackson is a well-known name ...

  5. HEART RETRANSPLANTATION

    Directory of Open Access Journals (Sweden)

    R. Sh. Saitgareev

    2016-01-01

    Full Text Available The number of patients with transplanted heart is continuously increasing; therefore, the number of patients requiring heart retransplantation grows. Analysis of the results of published studies focused on safety of cardiac retransplantation and risk factors for adverse events in perioperative, early and late postoperative periods is presented in our review. The results of published studies suggest that heart retransplantation is the main radical treatment option for cardiac allograft dysfunction, but the results of heart retransplantation are slightly worse than those of primary cardiac transplantation. On the other hand, the favorable long-term prognosis after heart retransplantation should be expected in carefully selected recipients. 

  6. The Effect of Dopaminergic Medication on Beat-Based Auditory Timing in Parkinson's Disease

    Directory of Open Access Journals (Sweden)

    Daniel J Cameron

    2016-02-01

    Full Text Available Parkinson’s disease (PD adversely affects timing abilities. Beat-based timing is a mechanism that times events relative to a regular interval, such as the ‘beat’ in musical rhythm, and is impaired in PD. It is unknown if dopaminergic medication influences beat-based timing in PD. Here we tested beat-based timing over two sessions in participants with PD (OFF then ON dopaminergic medication, and unmedicated control participants. People with PD and control participants completed two tasks. The first was a discrimination task in which participants compared two rhythms and determined whether they were the same or different. Rhythms either had a beat structure (metric simple rhythms, or did not (metric complex rhythms, as in previous studies. Discrimination accuracy was analyzed to test for the effects of beat structure, as well as differences between participants with PD and controls, and effects of medication (PD group only. The second task was the Beat Alignment Test (BAT, in which participants listened to music with regular tones superimposed, and responded as to whether the tones were ‘on’ or ‘off’ the beat of the music. Accuracy was analyzed to test for differences between participants with PD and controls, and for an effect of medication in patients.Both patients and controls discriminated metric simple rhythms better than metric complex rhythms. Controls also improved at the discrimination task in the second vs. first session, whereas people with PD did not. For participants with PD, the difference in performance between metric simple and metric complex rhythms was greater (sensitivity to changes in simple rhythms increased and sensitivity to changes in complex rhythms decreased when ON vs. OFF medication. Performance also worsened with disease severity. For the Beat Alignment Test, no group differences or effects of medication were found. Overall, these findings suggest that timing is impaired in PD, and that dopaminergic

  7. Considerations in the assessment of heart rate variability in biobehavioral research

    Directory of Open Access Journals (Sweden)

    Daniel S Quintana

    2014-07-01

    Full Text Available Heart rate variability (HRV refers to various methods of assessing the beat-to-beat variation in the heart over time, in order to draw inference on the outflow of the autonomic nervous system. Easy access to measuring HRV has led to a plethora of studies within emotion science and psychology assessing autonomic regulation, but significant caveats exist due to the complicated nature of HRV. Firstly, both breathing and blood pressure regulation have their own relationship to social, emotional and cognitive experiments – if this is the case are we observing heart rate changes as a consequence of breathing changes? Secondly, experiments often have poor internal and external controls. In this review we highlight the interrelationships between heart rate and respiration, as well as presenting recommendations for researchers to use when collecting data for HRV assessment. Namely, we highlight the superior utility of within-subjects designs along with the importance of establishing an appropriate baseline and monitoring respiration.

  8. Design and evaluation of a handheld impedance plethysmograph for measuring heart rate variability

    DEFF Research Database (Denmark)

    Kristiansen, N. K.; Fleischer, J.; Jensen, M. S.

    2005-01-01

    Heart rate variability (HRV) analysis from 10s ECGs has been shown to be reliable. However, the short examination time warrants a user-friendly system that can be used for ad-hoc examinations without normal preparation, unlike ECG. A handheld device has been developed that can measure ultra...... was performed by a digital signal processor, where the discrete heart beats were detected using a correlation algorithm that could adapt to individual pulse wave shapes to account for biological variation. The novel device was evaluated in 20 mainly young volunteers, using 10 s time-correlated ECG recordings...... as the reference method. Agreement between the two methods in measuring heart rate and root mean square of successive differences in the heart beat interval (RMSSD) was analysed using correlation coefficients (Pearson's R-2), mean differences with 95% confidence intervals and 95% limits of agreement, and Bland...

  9. Effect of muscle mass and intensity of isometric contraction on heart rate.

    Science.gov (United States)

    Gálvez, J M; Alonso, J P; Sangrador, L A; Navarro, G

    2000-02-01

    The purpose of this study was to determine the effect of muscle mass and the level of force on the contraction-induced rise in heart rate. We conducted an experimental study in a sample of 28 healthy men between 20 and 30 yr of age (power: 95%, alpha: 5%). Smokers, obese subjects, and those who performed regular physical activity over a certain amount of energetic expenditure were excluded from the study. The participants exerted two types of isometric contractions: handgrip and turning a 40-cm-diameter wheel. Both were sustained to exhaustion at 20 and 50% of maximal force. Twenty-five subjects finished the experiment. Heart rate increased a mean of 15.1 beats/min [95% confidence interval (CI): 5.5-24.6] from 20 to 50% handgrip contractions, and 20.7 beats/min (95% CI: 11.9-29.5) from 20 to 50% wheel-turn contractions. Heart rate also increased a mean of 13.3 beats/min (95% CI: 10.4-16.1) from handgrip to wheel-turn contractions at 20% maximal force, and 18.9 beats/min (95% CI: 9. 8-28.0) from handgrip to wheel-turn contractions at 50% maximal force. We conclude that the magnitude of the heart rate increase during isometric exercise is related to the intensity of the contraction and the mass of the contracted muscle.

  10. Accelerated high-frame-rate mouse heart cine-MRI using compressed sensing reconstruction

    NARCIS (Netherlands)

    Motaal, Abdallah G.; Coolen, Bram F.; Abdurrachim, Desiree; Castro, Rui M.; Prompers, Jeanine J.; Florack, Luc M. J.; Nicolay, Klaas; Strijkers, Gustav J.

    2013-01-01

    We introduce a new protocol to obtain very high-frame-rate cinematographic (Cine) MRI movies of the beating mouse heart within a reasonable measurement time. The method is based on a self-gated accelerated fast low-angle shot (FLASH) acquisition and compressed sensi ng reconstruction. Key to our

  11. Functional imaging of murine hearts using accelerated self-gated UTE cine MRI

    NARCIS (Netherlands)

    Motaal, Abdallah G.; Noorman, Nils; de Graaf, Wolter L.; Hoerr, Verena; Florack, Luc M. J.; Nicolay, Klaas; Strijkers, Gustav J.

    2015-01-01

    We introduce a fast protocol for ultra-short echo time (UTE) Cine magnetic resonance imaging (MRI) of the beating murine heart. The sequence involves a self-gated UTE with golden-angle radial acquisition and compressed sensing reconstruction. The self-gated acquisition is performed asynchronously

  12. Rapid-Sequence Intubation in the Left-Lateral Tilt Position in a Pregnant Woman with Premature Placental Abruption Utilizing a Videolaryngoscope

    Directory of Open Access Journals (Sweden)

    Kenta Nakao

    2015-04-01

    Full Text Available Case - A 24-year-old pregnant woman was admitted to our hospital with decreased fetal heart rate. Obstetric examination revealed premature placental abruption; emergent caesarean section was planned under general anesthesia. On entering the operating room, the patient showed severe vital sign deterioration (blood pressure, 75/45 mm Hg; heart rate, 142 beats per minute. As left uterine displacement may worsen the premature placental abruption, the patient was placed in the left-lateral tilt position by rotating the operating table to release compression on the inferior vena cava by theuterus. To avoid circulatory collapse, rapid-sequence intubation was performed in this position. Tracheal intubation was performed with the Pentax-AWS Airwayscope (AWS videolaryngoscope, AWS; HOYA, Japan to obtain a good laryngeal view and minimize stress from laryngoscopy. After sufficient oxygenation, 120 mg of thiopental was administered. A second anesthesiologist performed cricoid pressure and 50 mg of rocuronium was administered after confirming loss of consciousness. This was followed by insertion of the AWS with a thin intlock into the mouth. Tracheal intubation was performed uneventfully. Discussion - Rapid-sequence intubation in the left-lateral tilted position with the AWS videolaryngoscope may be beneficial for pregnant women with vital sign deterioration.

  13. Effect of changing heart rate during treatment of hypertension on incidence of heart failure.

    Science.gov (United States)

    Okin, Peter M; Kjeldsen, Sverre E; Julius, Stevo; Hille, Darcy A; Dahlöf, Björn; Devereux, Richard B

    2012-03-01

    An elevated heart rate (HR) at rest at baseline is associated with an increased risk of incident heart failure (HF) and with greater cardiovascular event rates in patients with chronic HF. However, despite the high attributable risk of hypertension for HF, whether the in-treatment HR predicts incident HF in patients with treated hypertension has not been evaluated. The HR was evaluated on annual electrocardiograms from 9,024 patients with hypertension without HF who were treated with losartan- or atenolol-based regimens. During a mean follow-up of 4.7 ± 1.1 years, HF developed in 285 patients (3.2%). On multivariate Cox analyses adjusted for randomized treatment, the baseline risk factors for HF, baseline and in-treatment blood pressure, QRS duration, and electrocardiographic left ventricular hypertrophy, a greater in-treatment HR predicted a 45% greater adjusted risk of new HF for every 10-beats/min increase in the HR (95% confidence interval [CI] 34% to 57%) or a 159% greater risk of HF in patients with the persistence or development of a HR of ≥84 beats/min (95% CI 88% to 257%). In contrast, with adjustment for the same covariates, the baseline HR as a continuous variable was a significantly less powerful predictor of new HF (hazard ratio 1.15 per 10 beats/min, 95% CI 1.03 to 1.28) and a baseline HR of ≥84 beats/min did not predict new HF (hazard ratio 1.00, 95% CI 0.63 to 1.58). In conclusion, a greater in-treatment HR on the serial electrocardiograms predicts a greater risk of incident HF during antihypertensive treatment, independent of the covariates, in patients with hypertension with electrocardiographic left ventricular hypertrophy. These findings support serial HR assessment to improve the risk stratification of patients with hypertension. Copyright © 2012 Elsevier Inc. All rights reserved.

  14. Human cortical responses to slow and fast binaural beats reveal multiple mechanisms of binaural hearing.

    Science.gov (United States)

    Ross, Bernhard; Miyazaki, Takahiro; Thompson, Jessica; Jamali, Shahab; Fujioka, Takako

    2014-10-15

    When two tones with slightly different frequencies are presented to both ears, they interact in the central auditory system and induce the sensation of a beating sound. At low difference frequencies, we perceive a single sound, which is moving across the head between the left and right ears. The percept changes to loudness fluctuation, roughness, and pitch with increasing beat rate. To examine the neural representations underlying these different perceptions, we recorded neuromagnetic cortical responses while participants listened to binaural beats at a continuously varying rate between 3 Hz and 60 Hz. Binaural beat responses were analyzed as neuromagnetic oscillations following the trajectory of the stimulus rate. Responses were largest in the 40-Hz gamma range and at low frequencies. Binaural beat responses at 3 Hz showed opposite polarity in the left and right auditory cortices. We suggest that this difference in polarity reflects the opponent neural population code for representing sound location. Binaural beats at any rate induced gamma oscillations. However, the responses were largest at 40-Hz stimulation. We propose that the neuromagnetic gamma oscillations reflect postsynaptic modulation that allows for precise timing of cortical neural firing. Systematic phase differences between bilateral responses suggest that separate sound representations of a sound object exist in the left and right auditory cortices. We conclude that binaural processing at the cortical level occurs with the same temporal acuity as monaural processing whereas the identification of sound location requires further interpretation and is limited by the rate of object representations. Copyright © 2014 the American Physiological Society.

  15. A Simpler Explanation for Vestibular Influence on Beat Perception: No Specialized Unit Needed

    Directory of Open Access Journals (Sweden)

    Mark Riggle

    2009-04-01

    Full Text Available Some researchers have hypothesized the existence of a specialized brain unit for beat perception in music which is directly influenced by vestibular stimulation arising from motion. They also suggest that the unit is involved in the entrainment of movement to music. However, the data used to support this hypothesis may be explained by a simpler phenomenon: the audiogravic and audiogyral effect. This effect is not related to beat perception at all but deals with perceived sound changes under accelerations. If the perception of a sound changes as a consequence of acceleration of the vestibular system, and those accelerations are timed to coincide with particular beats in a stream of unaccented beats, then those beats will actually sound different. The detection of a given meter in that unaccented stream will therefore arise from this change in sound processing, with no need for a specialized brain mechanism for beat perception. There is no direct evidence supporting the existence of an innate brain unit.

  16. Experimental evidence for synchronization to a musical beat in a nonhuman animal.

    Science.gov (United States)

    Patel, Aniruddh D; Iversen, John R; Bregman, Micah R; Schulz, Irena

    2009-05-26

    The tendency to move in rhythmic synchrony with a musical beat (e.g., via head bobbing, foot tapping, or dance) is a human universal [1] yet is not commonly observed in other species [2]. Does this ability reflect a brain specialization for music cognition, or does it build on neural circuitry that ordinarily serves other functions? According to the "vocal learning and rhythmic synchronization" hypothesis [3], entrainment to a musical beat relies on the neural circuitry for complex vocal learning, an ability that requires a tight link between auditory and motor circuits in the brain [4, 5]. This hypothesis predicts that only vocal learning species (such as humans and some birds, cetaceans, and pinnipeds, but not nonhuman primates) are capable of synchronizing movements to a musical beat. Here we report experimental evidence for synchronization to a beat in a sulphur-crested cockatoo (Cacatua galerita eleonora). By manipulating the tempo of a musical excerpt across a wide range, we show that the animal spontaneously adjusts the tempo of its rhythmic movements to stay synchronized with the beat. These findings indicate that synchronization to a musical beat is not uniquely human and suggest that animal models can provide insights into the neurobiology and evolution of human music [6].

  17. Beat gestures improve word recall in 3- to 5-year-old children.

    Science.gov (United States)

    Igualada, Alfonso; Esteve-Gibert, Núria; Prieto, Pilar

    2017-04-01

    Although research has shown that adults can benefit from the presence of beat gestures in word recall tasks, studies have failed to conclusively generalize these findings to preschool children. This study investigated whether the presence of beat gestures helps children to recall information when these gestures have the function of singling out a linguistic element in its discourse context. A total of 106 3- to 5-year-old children were asked to recall a list of words within a pragmatically child-relevant context (i.e., a storytelling activity) in which the target word was or was not accompanied by a beat gesture. Results showed that children recalled the target word significantly better when it was accompanied by a beat gesture than when it was not, indicating a local recall effect. Moreover, the recall of adjacent non-target words did not differ depending on the condition, revealing that beat gestures seem to have a strictly local highlighting function (i.e., no global recall effect). These results demonstrate that preschoolers benefit from the pragmatic contribution offered by beat gestures when they function as multimodal markers of prominence. Copyright © 2016 Elsevier Inc. All rights reserved.

  18. A high-density EEG investigation into steady state binaural beat stimulation.

    Directory of Open Access Journals (Sweden)

    Peter Goodin

    Full Text Available Binaural beats are an auditory phenomenon that has been suggested to alter physiological and cognitive processes including vigilance and brainwave entrainment. Some personality traits measured by the NEO Five Factor Model have been found to alter entrainment using pulsing light stimuli, but as yet no studies have examined if this occurs using steady state presentation of binaural beats for a relatively short presentation of two minutes. This study aimed to examine if binaural beat stimulation altered vigilance or cortical frequencies and if personality traits were involved. Thirty-one participants were played binaural beat stimuli designed to elicit a response at either the Theta (7 Hz or Beta (16 Hz frequency bands while undertaking a zero-back vigilance task. EEG was recorded from a high-density electrode cap. No significant differences were found in vigilance or cortical frequency power during binaural beat stimulation compared to a white noise control period. Furthermore, no significant relationships were detected between the above and the Big Five personality traits. This suggests a short presentation of steady state binaural beats are not sufficient to alter vigilance or entrain cortical frequencies at the two bands examined and that certain personality traits were not more susceptible than others.

  19. Episodic arterial oxygen desaturation and heart rate variations following major abdominal surgery

    DEFF Research Database (Denmark)

    Rosenberg, J; Dirkes, W E; Kehlet, H

    1989-01-01

    In 20 patients undergoing elective major abdominal surgery, heart rate and arterial oxygen saturation were monitored continuously during the night 2 days before operation and during the first and second nights after operation (23:00 to 07:30). Mean heart rate increased by 16 beat min-1 (P less than...... arrhythmias on the morning of the third day after operation. In another patient the episodes of desaturation correlated with increases in heart rate. There was no correlation between administration of opioids and heart rate and saturation disturbances. The mechanism and clinical relevance of episodic...

  20. Wife beating refusal among women of reproductive age in urban and rural Ethiopia.

    Science.gov (United States)

    Gurmu, Eshetu; Endale, Senait

    2017-03-16

    Wife beating is the most common and widespread form of intimate partner violence in Ethiopia. It results in countless severe health, socio-economic and psychological problems and has contributed to the violation of human rights including the liberty of women to enjoy conjugal life. The main purpose of this study is to assess the levels and patterns of wife beating refusal and its associated socio-cultural and demographic factors in rural and urban Ethiopia. The 2011 Ethiopian Demographic and Health Survey (EDHS) data based on 11,097 and 5287 women in the reproductive age group (i.e. 15-49 years) living in rural and urban areas, respectively,were used in this study. Cronbach's alpha was used to assess the internal consistency of the measure of women's attitudes towards wife beating. The Statistical Package for Social Sciences was applied to analyze the data. A binary logistic regression model was fitted to identify variables that significantly predict respondents' refusal of wife beating. Separate analysis by a place of residence was undertaken as attitude towards wife beating vary between rural and urban areas. The likelihood of refusing wife beating in Ethiopia was significantly higher among urban women (54.2%) than rural women (24.5%). Although there was a significant variations in attitude towards refusing wife beating among different regions in Ethiopia, increasing educational level, high access to media, age of respondents were associated with high level of refusal of wife beating. In contrast, rural residence, being in marital union, high number of living children, being followers of some religions (Muslim followers in urban and Protestants in rural) were associated with low level of refusal of wife beating. The findings of this study reveal that wife beating in Ethiopia is a function of demographic and socio-cultural factors among which age and educational attainment of respondents, number of living children, religious affiliation, marital commitment and

  1. To beat or not to beat a tick: comparison of DNA extraction methods for ticks (Ixodes scapularis

    Directory of Open Access Journals (Sweden)

    Alyssa D. Ammazzalorso

    2015-08-01

    Full Text Available Background. Blacklegged ticks (Ixodes scapularis are important disease vectors in the United States, known to transmit a variety of pathogens to humans, including bacteria, protozoa, and viruses. Their importance as a disease vector necessitates reliable and comparable methods for extracting microbial DNA from ticks. Furthermore, to explore the population genetics or genomics of this tick, appropriate DNA extraction techniques are needed for both the vector and its microbes. Although a few studies have investigated different methods of DNA isolation from ticks, they are limited in the number and types of DNA extraction and lack species-specific quantification of DNA yield.Methods. Here we determined the most efficient and consistent method of DNA extraction from two different developmental stages of I. scapularis—nymph and adult—that are the most important for disease transmission. We used various methods of physical disruption of the hard, chitinous exoskeleton, as well as commercial and non-commercial DNA isolation kits. To gauge the effectiveness of these methods, we quantified the DNA yield and confirmed the DNA quality via PCR of both tick and microbial genetic material.Results. DNA extraction using the Thermo GeneJET Genomic DNA Purification Kit resulted in the highest DNA yields and the most consistent PCR amplification when combined with either cutting or bead beating with select matrices across life stages. DNA isolation methods using ammonium hydroxide as well as the MoBio PowerSoil kit also produced strong and successful PCR amplification, but only for females.Discussion. We contrasted a variety of readily available methods of DNA extraction from single individual blacklegged ticks and presented the results through a quantitative and qualitative assessment.

  2. Hypoplastic left heart syndrome

    Science.gov (United States)

    HLHS; Congenital heart - hypoplastic left heart; Cyanotic heart disease - hypoplastic left heart ... Hypoplastic left heart is a rare type of congenital heart disease. It is more common in males than in females. As ...

  3. Binaural beat technology in humans: a pilot study to assess psychologic and physiologic effects.

    Science.gov (United States)

    Wahbeh, Helané; Calabrese, Carlo; Zwickey, Heather

    2007-01-01

    Binaural beat technology (BBT) products are sold internationally as personal development and health improvement tools. Producers suggest benefit from regular listening to binaural beats including reduced stress and anxiety, and increased focus, concentration, motivation, confidence, and depth in meditation. Binaural beats are auditory brainstem responses that originate in the superior olivary nucleus as a result of different frequency auditory stimuli provided to each ear. Listeners to binaural beat "hear" a beat at a frequency equal to the difference between the frequencies of the applied tones. The objectives of this pilot study were to gather preliminary data on psychologic and physiologic effects of 60 days daily use of BBT for hypothesis generation and to assess compliance, feasibility, and safety for future studies. Uncontrolled pilot study. Eight healthy adults participated in the study. Participants listened to a CD with delta (0-4 Hz) binaural beat frequencies daily for 60 days. Psychologic and physiological data were collected before and after a 60-day intervention. PSYCHOLOGIC: Depression (Beck Depression Inventory-2), anxiety (State-Trait Anxiety Inventory), mood (Profile of Mood States), absorption (Tellegen Absorption Scale) and quality of Life (World Health Organization-Quality of Life Inventory). PHYSIOLOGICAL: Cortisol, dehydroepiandrosterone, melatonin, insulin-like growth factor-1, serotonin, dopamine, epinephrine, norepinephrine, weight, blood pressure, high sensitivity C-reactive protein. There was a decrease in trait anxiety (p = 0.004), an increase in quality of life (p = 0.03), and a decrease in insulin-like growth factor-1 (p = 0.01) and dopamine (p = 0.02) observed between pre- and postintervention measurements. Binaural beat technology may exhibit positive effect on self-reported psychologic measures, especially anxiety. Further research is warranted to explore the effects on anxiety using a larger, randomized and controlled trial.

  4. The effect of gamma-enhancing binaural beats on the control of feature bindings.

    Science.gov (United States)

    Colzato, Lorenza S; Steenbergen, Laura; Sellaro, Roberta

    2017-07-01

    Binaural beats represent the auditory experience of an oscillating sound that occurs when two sounds with neighboring frequencies are presented to one's left and right ear separately. Binaural beats have been shown to impact information processing via their putative role in increasing neural synchronization. Recent studies of feature-repetition effects demonstrated interactions between perceptual features and action-related features: repeating only some, but not all features of a perception-action episode hinders performance. These partial-repetition (or binding) costs point to the existence of temporary episodic bindings (event files) that are automatically retrieved by repeating at least one of their features. Given that neural synchronization in the gamma band has been associated with visual feature bindings, we investigated whether the impact of binaural beats extends to the top-down control of feature bindings. Healthy adults listened to gamma-frequency (40 Hz) binaural beats or to a constant tone of 340 Hz (control condition) for ten minutes before and during a feature-repetition task. While the size of visuomotor binding costs (indicating the binding of visual and action features) was unaffected by the binaural beats, the size of visual feature binding costs (which refer to the binding between the two visual features) was considerably smaller during gamma-frequency binaural beats exposure than during the control condition. Our results suggest that binaural beats enhance selectivity in updating episodic memory traces and further strengthen the hypothesis that neural activity in the gamma band is critically associated with the control of feature binding.

  5. Cross-cultural influences on rhythm processing: reproduction, discrimination, and beat tapping.

    Science.gov (United States)

    Cameron, Daniel J; Bentley, Jocelyn; Grahn, Jessica A

    2015-01-01

    The structures of musical rhythm differ between cultures, despite the fact that the ability to entrain movement to musical rhythm occurs in virtually all individuals across cultures. To measure the influence of culture on rhythm processing, we tested East African and North American adults on perception, production, and beat tapping for rhythms derived from East African and Western music. To assess rhythm perception, participants identified whether pairs of rhythms were the same or different. To assess rhythm production, participants reproduced rhythms after hearing them. To assess beat tapping, participants tapped the beat along with repeated rhythms. We expected that performance in all three tasks would be influenced by the culture of the participant and the culture of the rhythm. Specifically, we predicted that a participant's ability to discriminate, reproduce, and accurately tap the beat would be better for rhythms from their own culture than for rhythms from another culture. In the rhythm discrimination task, there were no differences in discriminating culturally familiar and unfamiliar rhythms. In the rhythm reproduction task, both groups reproduced East African rhythms more accurately than Western rhythms, but East African participants also showed an effect of cultural familiarity, leading to a significant interaction. In the beat tapping task, participants in both groups tapped the beat more accurately for culturally familiar than for unfamiliar rhythms. Moreover, there were differences between the two participant groups, and between the two types of rhythms, in the metrical level selected for beat tapping. The results demonstrate that culture does influence the processing of musical rhythm. In terms of the function of musical rhythm, our results are consistent with theories that musical rhythm enables synchronization. Musical rhythm may foster musical cultural identity by enabling within-group synchronization to music, perhaps supporting social cohesion.

  6. Heart rate recovery in patients with obstructive sleep apnea syndrome

    OpenAIRE

    Karaşen, Rıza Murat; ÇİFTÇİ, Bülent; Acar, Baran; YALÇIN, Ahmet Arif; GÜVEN, Selma FIRAT

    2014-01-01

    To demonstrate the effects of obstructive sleep apnea syndrome (OSAS) on baroregulatory function by using heart rate recovery (HRR) parameters. Materials and methods: Fifty-four moderate and severe OSAS patients were included in the study. HRR was defined as the difference in heart rate between peak exercise and 1 min later; a value of 18 beats/min was considered abnormal. OSAS patients were enrolled in the study as group 1 (normal HRR; n = 12) and group 2 (abnormal HRR, n = 42). Left ventr...

  7. Resting heart rate and the risk of hypertension and heart failure: a dose-response meta-analysis of prospective studies.

    Science.gov (United States)

    Shi, Yuanyuan; Zhou, Wen; Liu, Xuejiao; Ping, Zhiguang; Li, Yu-Qian; Wang, Chongjian; Lu, Jie; Mao, Zhen-Xing; Zhao, Jingzhi; Yin, Lei; Zhang, Dongdong; Li, Linlin

    2017-11-25

    Studies on the relationship of resting heart rate to the risks of hypertension and heart failure have been inconsistent, and the question as to whether there is a linear association between them is unanswered. To evaluate this possible relationship, we carried out a dose-response meta-analysis of studies that looked at risks associated with resting heart rate and hypertension or heart failure. We searched PubMed, Embase, CNKI and WanFang databases for articles published before 15 June 2017. A random-effect model was used to pool relative risks and 95% confidence intervals. Restricted cubic spline analysis was used to model the resting heart rate-hypertension and heart failure risk association. We identified 13 and 17 cohort studies for hypertension and heart failure, respectively. The risk for each disease, respectively, increased by 11% relative risk: 1.11 (95% confidence interval: 1.07-1.15) and 19% relative risk: 1.19 (95% confidence interval: 1.13-1.25) for each 10 beats-per-minute increment in resting heart rate. The relationship between resting heart rate and hypertension or heart failure was consistent in most subgroup analyses except for gender subgroups, with no significant association observed in the women subgroup. The results provide no evidence of a nonlinear association of elevated resting heart rate with hypertension and heart failure risk. Resting heart rate shows a linear positive association with the incidence of hypertension and heart failure.

  8. Heart Failure in Pediatric Patients With Congenital Heart Disease.

    Science.gov (United States)

    Hinton, Robert B; Ware, Stephanie M

    2017-03-17

    Heart failure (HF) is a complex clinical syndrome resulting from diverse primary and secondary causes and shared pathways of disease progression, correlating with substantial mortality, morbidity, and cost. HF in children is most commonly attributable to coexistent congenital heart disease, with different risks depending on the specific type of malformation. Current management and therapy for HF in children are extrapolated from treatment approaches in adults. This review discusses the causes, epidemiology, and manifestations of HF in children with congenital heart disease and presents the clinical, genetic, and molecular characteristics that are similar or distinct from adult HF. The objective of this review is to provide a framework for understanding rapidly increasing genetic and molecular information in the challenging context of detailed phenotyping. We review clinical and translational research studies of HF in congenital heart disease including at the genome, transcriptome, and epigenetic levels. Unresolved issues and directions for future study are presented. © 2017 American Heart Association, Inc.

  9. Effect of uterine contractions on fetal heart rate in pregnancy: a prospective observational study.

    Science.gov (United States)

    Sletten, Julie; Kiserud, Torvid; Kessler, Jörg

    2016-10-01

    The new Holter monitoring technology enables long-term electrocardiographic recording of the fetal heart rate without discomfort for the mother. The aim of the study was to assess the feasibility of a fetal Holter monitor. This technology was further used to study fetal heart rate outside the hospital setting during normal daily activities and to test the hypothesis that uterine activity during pregnancy influences fetal heart rate. Prospective observational study including 12 healthy pregnant women at 20-40 weeks of gestation. Data were collected using the Monica AN24 system. Outcome measures were fetal heart rate, maternal heart rate, and uterine activity categorized according to the strength of the electrohysterographic signal. The recordings had a median length of 18.8 h, and fetal heart rate and maternal heart rate were obtained with success rates of 73.1 and 99.9%, respectively. Uterine activity was found to affect fetal heart rate in all participants. Compared with the basal tone and mild levels of uterine activity, moderate and strong levels of uterine activity were associated with increases in fetal heart rate of 4.0 and 5.7 beats/min, respectively. At night, the corresponding increases were 4.9 and 7.6 beats/min. Linear correlations were found between maternal heart rate and fetal heart rate in 11 of the 12 cases, with a mean coefficient beta of 0.189. Both maternal heart rate and fetal heart rate exhibited a diurnal pattern, with lower heart rates being recorded at night. Uterine activity during pregnancy is associated with a graded response in fetal heart rate and may represent a physiological challenge for the development and adaptation of the fetal cardiovascular system. © 2016 Nordic Federation of Societies of Obstetrics and Gynecology.

  10. The effects of auditory stimulation with music on heart rate variability in healthy women

    Directory of Open Access Journals (Sweden)

    Adriano L. Roque

    2013-07-01

    Full Text Available OBJECTIVES: There are no data in the literature with regard to the acute effects of different styles of music on the geometric indices of heart rate variability. In this study, we evaluated the acute effects of relaxant baroque and excitatory heavy metal music on the geometric indices of heart rate variability in women. METHODS: We conducted this study in 21 healthy women ranging in age from 18 to 35 years. We excluded persons with previous experience with musical instruments and persons who had an affinity for the song styles. We evaluated two groups: Group 1 (n = 21, who were exposed to relaxant classical baroque musical and excitatory heavy metal auditory stimulation; and Group 2 (n = 19, who were exposed to both styles of music and white noise auditory stimulation. Using earphones, the volunteers were exposed to baroque or heavy metal music for five minutes. After the first music exposure to baroque or heavy metal music, they remained at rest for five minutes; subsequently, they were re-exposed to the opposite music (70-80 dB. A different group of women were exposed to the same music styles plus white noise auditory stimulation (90 dB. The sequence of the songs was randomized for each individual. We analyzed the following indices: triangular index, triangular interpolation of RR intervals and Poincaré plot (standard deviation of instantaneous beat-by-beat variability, standard deviation of the long-term RR interval, standard deviation of instantaneous beat-by-beat variability and standard deviation of the long-term RR interval ratio, low frequency, high frequency, low frequency/high frequency ratio, standard deviation of all the normal RR intervals, root-mean square of differences between the adjacent normal RR intervals and the percentage of adjacent RR intervals with a difference of duration greater than 50 ms. Heart rate variability was recorded at rest for 10 minutes. RESULTS: The triangular index and the standard deviation of

  11. The effects of auditory stimulation with music on heart rate variability in healthy women.

    Science.gov (United States)

    Roque, Adriano L; Valenti, Vitor E; Guida, Heraldo L; Campos, Mônica F; Knap, André; Vanderlei, Luiz Carlos M; Ferreira, Lucas L; Ferreira, Celso; Abreu, Luiz Carlos de

    2013-07-01

    There are no data in the literature with regard to the acute effects of different styles of music on the geometric indices of heart rate variability. In this study, we evaluated the acute effects of relaxant baroque and excitatory heavy metal music on the geometric indices of heart rate variability in women. We conducted this study in 21 healthy women ranging in age from 18 to 35 years. We excluded persons with previous experience with musical instruments and persons who had an affinity for the song styles. We evaluated two groups: Group 1 (n = 21), who were exposed to relaxant classical baroque musical and excitatory heavy metal auditory stimulation; and Group 2 (n = 19), who were exposed to both styles of music and white noise auditory stimulation. Using earphones, the volunteers were exposed to baroque or heavy metal music for five minutes. After the first music exposure to baroque or heavy metal music, they remained at rest for five minutes; subsequently, they were re-exposed to the opposite music (70-80 dB). A different group of women were exposed to the same music styles plus white noise auditory stimulation (90 dB). The sequence of the songs was randomized for each individual. We analyzed the following indices: triangular index, triangular interpolation of RR intervals and Poincaré plot (standard deviation of instantaneous beat-by-beat variability, standard deviation of the long-term RR interval, standard deviation of instantaneous beat-by-beat variability and standard deviation of the long-term RR interval ratio), low frequency, high frequency, low frequency/high frequency ratio, standard deviation of all the normal RR intervals, root-mean square of differences between the adjacent normal RR intervals and the percentage of adjacent RR intervals with a difference of duration greater than 50 ms. Heart rate variability was recorded at rest for 10 minutes. The triangular index and the standard deviation of the long-term RR interval indices were reduced

  12. In vitro detection of cardiotoxins or neurotoxins affecting ion channels or pumps using beating cardiomyocytes as alternative for animal testing

    OpenAIRE

    Nicolas, J.A.Y.; Hendriksen, P.J.M.; de Haan,; Koning, R.; Rietjens, I.M.C.M.; Bovee, T.F.H.

    2015-01-01

    The present study investigated if and to what extent murine stem cell-derived beating cardiomyocytes within embryoid bodies can be used as a broad screening in vitro assay for neurotoxicity testing, replacing for example in vivo tests for marine neurotoxins. Effect of nine model compounds, acting on either the Na+, K+, or Ca2+ channels or the Na+/K+ ATP-ase pump, on the beating was assessed. Diphenhydramine, veratridine, isradipine, verapamil and ouabain induced specific beating arrests that ...

  13. Impact of training load on the heart rate of horses

    Directory of Open Access Journals (Sweden)

    Eva Mlyneková

    2016-12-01

    Full Text Available In our work, we analyzed the effect of training load on the heart rate of horses in a simulated load by the loading regulator for horse motion Horse Gym 2000. In the experiment were observed 8 Slovak Warmblood horses (3 mares, 4 geldings, 1 stallion aged 6-10 years. The experiment was divided into two parts after three weeks. The speed of the tested horses was 4.9 km/h in the first part of experiment, in the second part was the speed 5.2 km/h with a gradual uphill up to 7 %. The tested horses achieved during the experiment an average heart rate level below 70 beats a minute, which is a light load. The maximum values of heart rate were recorded at 120 to 147 beats/min. Differences between tested horses in the values of heart rate were not statistically significant. After three weeks we recorded in the values of average and maximum heart rate onset of bradycardia, which is documented the adaptation of body to the specified load.

  14. Heart transplant

    Science.gov (United States)

    ... check for infections Tests of your kidney and liver Tests to evaluate your heart, such as EKG , echocardiogram , and cardiac catheterization Tests to look for cancer Tissue and blood typing , to help make sure your body will not reject the donated heart Ultrasound of your neck and legs You will want ...

  15. Heart Attack

    Science.gov (United States)

    ... This substance travels to your heart. A special camera uses the substance to produce pictures. These show ... guard against certain diseases, including heart disease. New studies have shown ... If you have an acute case of angina (chest pain), your doctor will probably ...

  16. Effective viscosity of a suspension of flagellar-beating microswimmers: Three-dimensional modeling.

    Science.gov (United States)

    Jibuti, Levan; Zimmermann, Walter; Rafaï, Salima; Peyla, Philippe

    2017-11-01

    Micro-organisms usually can swim in their liquid environment by flagellar or ciliary beating. In this numerical work, we analyze the influence of flagellar beating on the orbits of a swimming cell in a shear flow. We also calculate the effect of the flagellar beating on the rheology of a dilute suspension of microswimmers. A three-dimensional model is proposed for Chlamydomonas Reinhardtii swimming with a breaststroke-like beating of two anterior flagella modeled by two counter-rotating fore beads. The active swimmer model reveals unusual angular orbits in a linear shear flow. Namely, the swimmer sustains orientations transiently across the flow. Such behavior is a result of the interplay between shear flow and the swimmer's periodic beating motion of flagella, which exert internal torques on the cell body. This peculiar behavior has some significant consequences on the rheological properties of the suspension. We calculate Einstein's viscosity of the suspension composed of such isolated modeled microswimmers (dilute case) in a shear flow. We use numerical simulations based on a Rotne-Prager-like approximation for hydrodynamic interaction between simplified flagella and the cell body. The results show an increased intrinsic viscosity for active swimmer suspensions in comparison to nonactive ones as well as a shear thinning behavior in accordance with previous experimental measurements [Phys. Rev. Lett. 104, 098102 (2010)10.1103/PhysRevLett.104.098102].

  17. Soda-anthraquinone pulping of palm oil empty fruit bunches and beating of the resulting pulp.

    Science.gov (United States)

    Jiménez, L; Serrano, L; Rodríguez, A; Sánchez, R

    2009-02-01

    The influence of soda-anthraquinone pulping variables (temperature, time and soda concentration) and beating (number of PFI beating revolution) of palm oil empty fruit bunches (EFB) on the resulting paper sheets was studied, with a view to identifying the optimum operating conditions. Equations were derived that reproduced the properties of the paper sheets with errors less than 10-12% in 90-95% of cases. An optimum compromise was found as regards operating conditions (15% soda, 170 degrees C, 70 min and 2400 number of PFI beating revolutions) that provided paper properties departing by less than 12% from their optimum values (59.63 Nm/g tensile index, 4.48% stretch, 4.17 kN/g burst index and 7.20 m Nm(2)/g tear index), and a beating grade of 47.5 degrees SR, acceptable to obtain paper sheets. Because these conditions involve a lower soda, temperature, time and beating than those required to maximize the studied paper properties, they can save chemical reagents, energy and immobilized capital for industrial facilities. On the other hand, the stretch properties of these pulp beaten are higher than those of others non-wood pulps, as wheat straw and olive wood.

  18. Measurement of Ca channel activity of isolated adult rat heart cells using /sup 54/Mn

    Energy Technology Data Exchange (ETDEWEB)

    Haworth, R.A.; Goknur, A.B.; Berkoff, H.A.

    1989-02-01

    Isolated adult rat heart cells incubated with 5 microM Mn in a medium with 1 mM Ca showed a rapid phase of Mn binding plus a slow phase of Mn uptake. The rapid phase was extracellular binding, as judged by its temperature-insensitive removal by ethylene glycol bis(beta-aminoethyl ether) N, N'-tetraacetic acid. The slow linear phase represented cellular uptake, as judged by its release with digitonin plus the ionophore A23187. Isoproterenol increased the linear rate of Mn uptake and induced spontaneous beating activity in some cells. Both effects were inhibited by nitrendipine. Electrical stimulation of the cells in suspension increased the linear rate of cellular Mn uptake. The increase was potentiated by isoproterenol, and inhibited by nitrendipine or verapamil. Stimulation-dependent Mn uptake (per milligram protein) was greater for cells from 5- to 6-week-old rats than for 8- to 9-month-old female retired breeder rats, in the presence of isoproterenol. Ryanodine increased the stimulation-dependent Mn uptake in the presence of isoproterenol, but not in its absence. We conclude: (i) that cellular uptake of /sup 54/Mn is a good probe of Ca channel function; (ii) that isoproterenol promotes Mn influx by the channel in isolated heart cells; (iii) that cells from young rats (5-6 weeks) have a higher beta-adrenergically induced Ca channel activity than cells from mature rats (8-9 months); and (iv) that ryanodine promotes Ca channel activity (perhaps indirectly) in the presence of isoproterenol.

  19. Simple, heart-smart substitutions

    Science.gov (United States)

    Coronary artery disease - heart smart substitutions; Atherosclerosis - heart smart substitutions; Cholesterol - heart smart substitutions; Coronary heart disease - heart smart substitutions; Healthy diet - heart ...

  20. Arrhythmia susceptibility in senescent rat hearts

    Directory of Open Access Journals (Sweden)

    Stefano Rossi

    2014-01-01

    Full Text Available Cardiovascular disease increases with age as well as alterations of cardiac electrophysiological properties, but a detailed knowledge about changes in cardiac electrophysiology relevant to arrhythmogenesis in the elderly is relatively lacking. The aim of this study was to determine specific age-related changes in electrophysiological properties of the ventricles which can be related to a structural-functional arrhythmogenic substrate. Multiple epicardial electrograms were recorded on the ventricular surface of in vivo control and aged rats, while arrhythmia vulnerability was investigated by premature stimulation protocols. Single or multiple ectopic beats and sustained ventricular arrhythmias were frequently induced in aged but not in control hearts. Abnormal ventricular activation patterns during sinus rhythm and unchanged conduction velocity during point stimulation in aged hearts suggest the occurrence of impaired impulse conduction through the distal Purkinje system that might create a potential reentry substrate.

  1. Heart Rate Responses of a Head Referee During a Football Game.

    Science.gov (United States)

    Conti, D J; McClintock, S L

    1983-10-01

    In brief: To determine the heart rate responses of a football official to both physical and psychological stress during actual game conditions, a head referee was telemetered continuously from one- half hour before until the end of a college football game. The referee's cardiac system was stressed throughout the monitoring period: The highest average heart rate was 161 beats min(-1) (85% of maximum), and the lowest average heart rate was 140 beats min(-1) (74% of maximum). Because officiating is largely anaerobic, the sustained sinus tachycardia was probably caused by psychological stress. Football officials should have a maximal ECG stress test every year and participate in an aerobic conditioning program on a regular basis.

  2. A method for testing synchronization to a musical beat in domestic horses (Equus ferus caballus

    Directory of Open Access Journals (Sweden)

    Micah R. Bregman

    2013-08-01

    Full Text Available According to the "vocal learning and rhythmic synchronization hypothesis" (Patel, 2006, only species capable of complex vocal learning, such as humans and parrots, have the capacity to synchronize their movements to a musical beat. While empirical research to date on a few species (e.g., parrots and monkeys has supported this hypothesis, many species remain to be examined. Domestic horses are particularly important to study, as they are vocal non-learners who are occasionally reported to move in synchrony with a musical beat, based on informal observations. If these reports are substantiated by scientific experiments, this would challenge the vocal learning hypothesis and provide a new species for the comparative study of musical rhythm. Here we present a new method for testing whether horses can synchronize their trotting to a musical beat, including an illustration of data analysis based on data collected from one horse.

  3. Probing an Excited-State Atomic Transition Using Hyperfine Quantum Beat Spectroscopy

    CERN Document Server

    Wade, Christopher G; Keaveney, James; Adams, Charles S; Weatherill, Kevin J

    2014-01-01

    We describe a method to observe the dynamics of an excited-state transition in a room temperature atomic vapor using hyperfine quantum beats. Our experiment using cesium atoms consists of a pulsed excitation of the D2 transition, and continuous-wave driving of an excited-state transition from the 6P$_{3/2}$ state to the 7S$_{1/2}$ state. We observe quantum beats in the fluorescence from the 6P$_{3/2}$ state which are modified by the driving of the excited-state transition. The Fourier spectrum of the beat signal yields evidence of Autler-Townes splitting of the 6P$_{3/2}$, F = 5 hyperfine level and Rabi oscillations on the excited-state transition. A detailed model provides qualitative agreement with the data, giving insight to the physical processes involved.

  4. Eliminating the attentional blink through binaural beats: A case for tailored cognitive enhancement

    Directory of Open Access Journals (Sweden)

    Susan A. Reedijk

    2015-06-01

    Full Text Available Enhancing human cognitive performance is a topic that continues to spark scientific interest. Studies into cognitive enhancement techniques often fail to take inter-individual differences into account, however, which leads to underestimation of the effectiveness of these techniques. The current study investigated the effect of binaural beats, a cognitive enhancement technique, on attentional control in an attentional blink task. As predicted from a neurocognitive approach to cognitive control, high-frequency binaural beats eliminated the attentional blink, but only in individuals with low spontaneous eye-blink rates (indicating low striatal dopamine levels. This suggests that the way in which cognitive enhancement techniques, such as binaural beats, affect cognitive performance depends on inter-individual differences.

  5. Aerobic exercise during pregnancy and presence of fetal-maternal heart rate synchronization.

    Directory of Open Access Journals (Sweden)

    Peter Van Leeuwen

    Full Text Available It has been shown that short-term direct interaction between maternal and fetal heart rates may take place and that this interaction is affected by the rate of maternal respiration. The aim of this study was to determine the effect of maternal aerobic exercise during pregnancy on the occurrence of fetal-maternal heart rate synchronization.In 40 pregnant women at the 36th week of gestation, 21 of whom exercised regularly, we acquired 18 min. RR interval time series obtained simultaneously in the mothers and their fetuses from magnetocardiographic recordings. The time series of the two groups were examined with respect to their heart rate variability, the maternal respiratory rate and the presence of synchronization epochs as determined on the basis of synchrograms. Surrogate data were used to assess whether the occurrence of synchronization was due to chance.In the original data, we found synchronization occurred less often in pregnancies in which the mothers had exercised regularly. These subjects also displayed higher combined fetal-maternal heart rate variability and lower maternal respiratory rates. Analysis of the surrogate data showed shorter epochs of synchronization and a lack of the phase coordination found between maternal and fetal beat timing in the original data.The results suggest that fetal-maternal heart rate coupling is present but generally weak. Maternal exercise has a damping effect on its occurrence, most likely due to an increase in beat-to-beat differences, higher vagal tone and slower breathing rates.

  6. The incomplete bucindolol evaluation in acute myocardial infarction Trial (BEAT)

    DEFF Research Database (Denmark)

    Torp-Pedersen, Christian; Køber, Lars; Ball, Stephen

    2002-01-01

    The aim of this study was to evaluate the efficacy of adding the beta-blocker bucindolol to standard therapy shortly after a myocardial infarction in a high-risk population with reduced left ventricular function. METHODS: The study was planned to include 2000 patients with an enzyme confirmed...... myocardial infarction and severely reduced left ventricular f