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Sample records for human heart beats

  1. Computer Simulation of the Beating Human Heart

    Science.gov (United States)

    Peskin, Charles S.; McQueen, David M.

    2001-06-01

    The mechanical function of the human heart couples together the fluid mechanics of blood and the soft tissue mechanics of the muscular heart walls and flexible heart valve leaflets. We discuss a unified mathematical formulation of this problem in which the soft tissue looks like a specialized part of the fluid in which additional forces are applied. This leads to a computational scheme known as the Immersed Boundary (IB) method for solving the coupled equations of motion of the whole system. The IB method is used to construct a three-dimensional Virtual Heart, including representations of all four chambers of the heart and all four valves, in addition to the large arteries and veins that connect the heart to the rest of the circulation. The chambers, valves, and vessels are all modeled as collections of elastic (and where appropriate, actively contractile) fibers immersed in viscous incompressible fluid. Results are shown as a computer-generated video animation of the beating heart.

  2. Healthcare performance and the effects of the binaural beats on human blood pressure and heart rate.

    Science.gov (United States)

    Carter, Calvin

    2008-01-01

    Binaural beats are the differences in two different frequencies (in the range of 30-1000 Hz). Binaural beats are played through headphones and are perceived by the superior olivary nucleus of each hemisphere of the brain. The brain perceives the binaural beat and resonates to its frequency (frequency following response). Once the brain is in tune with the binaural beat it produces brainwaves of that frequency altering the listener's state of mind. In this experiment, the effects of the beta and theta binaural beat on human blood pressure and pulse were studied. Using headphones, three sounds were played for 7 minutes each to 12 participants: the control,- the sound of a babbling brook (the background sound to the two binaural beats), the beta binaural beat (20 Hz), and the theta binaural beat (7 Hz). Blood pressure and pulse were recorded before and after each sound was played. Each participant was given 2 minutes in-between each sound. The results showed that the control and the two binaural beats did not affect the 12 participant's blood pressure or pulse (p > 0.05). One reason for this may be that the sounds were not played long enough for the brain to either perceive and/or resonate to the frequency. Another reason why the sounds did not affect blood pressure and pulse may be due to the participant's age since older brains may not perceive the binaural beats as well as younger brains.

  3. Dynamic focusing in the zebrafish beating heart

    Science.gov (United States)

    Andrés-Delgado, L.; Peralta, M.; Mercader, N.; Ripoll, J.

    2016-03-01

    Of the large amount of the animal models available for cardiac research, the zebrafish is extremely valuable due to its transparency during early stages of development. In this work a dual illumination laser sheet microscope with simultaneous dual camera imaging is used to image the beating heart at 200 fps, dynamically and selectively focusing inside the beating heart through the use of a tunable lens. This dual color dynamic focusing enables imaging with cellular resolution at unprecedented high frame rates, allowing 3D imaging of the whole beating heart of embryonic zebrafish.

  4. Mercury Beating Heart: Modifications to the Classical Demonstration

    Science.gov (United States)

    Najdoski, Metodija; Mirceski, Valentin; Petrusevski, Vladimir M.; Demiri, Sani

    2007-01-01

    The mercury beating heart (MBH) is a commonly performed experiment, which is based on varying oxidizing agents and substituting other metals for iron. Various modified versions of the classical demonstration of the experiment are presented.

  5. Model for the heart beat-to-beat time series during meditation

    Science.gov (United States)

    Capurro, A.; Diambra, L.; Malta, C. P.

    2003-09-01

    We present a model for the respiratory modulation of the heart beat-to-beat interval series. The model consists of a pacemaker, that simulates the membrane potential of the sinoatrial node, modulated by a periodic input signal plus correlated noise that simulates the respiratory input. The model was used to assess the waveshape of the respiratory signals needed to reproduce in the phase space the trajectory of experimental heart beat-to-beat interval data. The data sets were recorded during meditation practices of the Chi and Kundalini Yoga techniques. Our study indicates that in the first case the respiratory signal has the shape of a smoothed square wave, and in the second case it has the shape of a smoothed triangular wave.

  6. Model for the respiratory modulation of the heart beat-to-beat time interval series

    Science.gov (United States)

    Capurro, Alberto; Diambra, Luis; Malta, C. P.

    2005-09-01

    In this study we present a model for the respiratory modulation of the heart beat-to-beat interval series. The model consists of a set of differential equations used to simulate the membrane potential of a single rabbit sinoatrial node cell, excited with a periodic input signal with added correlated noise. This signal, which simulates the input from the autonomous nervous system to the sinoatrial node, was included in the pacemaker equations as a modulation of the iNaK current pump and the potassium current iK. We focus at modeling the heart beat-to-beat time interval series from normal subjects during meditation of the Kundalini Yoga and Chi techniques. The analysis of the experimental data indicates that while the embedding of pre-meditation and control cases have a roughly circular shape, it acquires a polygonal shape during meditation, triangular for the Kundalini Yoga data and quadrangular in the case of Chi data. The model was used to assess the waveshape of the respiratory signals needed to reproduce the trajectory of the experimental data in the phase space. The embedding of the Chi data could be reproduced using a periodic signal obtained by smoothing a square wave. In the case of Kundalini Yoga data, the embedding was reproduced with a periodic signal obtained by smoothing a triangular wave having a rising branch of longer duration than the decreasing branch. Our study provides an estimation of the respiratory signal using only the heart beat-to-beat time interval series.

  7. Efficient heart beat detection using embedded system electronics

    Science.gov (United States)

    Ramasamy, Mouli; Oh, Sechang; Varadan, Vijay K.

    2014-04-01

    The present day bio-technical field concentrates on developing various types of innovative ambulatory and wearable devices to monitor several bio-physical, physio-pathological, bio-electrical and bio-potential factors to assess a human body's health condition without intruding quotidian activities. One of the most important aspects of this evolving technology is monitoring heart beat rate and electrocardiogram (ECG) from which many other subsidiary results can be derived. Conventionally, the devices and systems consumes a lot of power since the acquired signals are always processed on the receiver end. Because of this back end processing, the unprocessed raw data is transmitted resulting in usage of more power, memory and processing time. This paper proposes an innovative technique where the acquired signals are processed by a microcontroller in the front end of the module and just the processed signal is then transmitted wirelessly to the display unit. Therefore, power consumption is considerably reduced and clearer data analysis is performed within the module. This also avoids the need for the user to be educated about usage of the device and signal/system analysis, since only the number of heart beats will displayed at the user end. Additionally, the proposed concept also eradicates the other disadvantages like obtrusiveness, high power consumption and size. To demonstrate the above said factors, a commercial controller board was used to extend the monitoring method by using the saved ECG data from a computer.

  8. 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

  9. Beat-to-beat heart rate detection in multi-lead abdominal fetal ECG recordings.

    Science.gov (United States)

    Peters, C H L; van Laar, J O E H; Vullings, R; Oei, S G; Wijn, P F F

    2012-04-01

    Reliable monitoring of fetal condition often requires more information than is provided by cardiotocography, the standard technique for fetal monitoring. Abdominal recording of the fetal electrocardiogram may offer valuable additional information, but unfortunately is troubled by poor signal-to-noise ratios during certain parts of pregnancy. To increase the usability of abdominal fetal ECG recordings, an algorithm was developed that enhances fetal QRS complexes in these recordings and thereby provides a promising method for detecting the beat-to-beat fetal heart rate in recordings with poor signal-to-noise ratios. The method was evaluated on generated recordings with controlled signal-to-noise ratios and on actual recordings that were performed in clinical practice and were annotated by two independent experts. The evaluation on the generated signals demonstrated excellent results (sensitivity of 0.98 for SNR≥1.5). Only for SNRheart rate detection exceeded 2 ms, which may still suffice for cardiotocography but is unacceptable for analysis of the beat-to-beat fetal heart rate variability. The sensitivity and positive predictive value of the method in actual recordings were reduced to approximately 90% for SNR≤2.4, but were excellent for higher signal-to-noise ratios.

  10. Uterus transplantation: From animal models through the first heart beating pregnancy to the first human live birth.

    Science.gov (United States)

    Ozkan, Omer; Dogan, Nasuh Utku; Ozkan, Ozlenen; Mendilcioglu, Inanc; Dogan, Selen; Aydinuraz, Batu; Simsek, Mehmet

    2016-07-01

    Absolute uterine factor infertility affects 3-5% of the general population, and unfortunately this condition is untreatable. There are some available options, including surrogacy or adoption, but neither of these suits each and every woman who desires to have her own genetic child. With recent advances in surgery and transplant immunology, uterus transplantation may be a source of hope for these women with uterine infertility. In the last decade, a number of animal species including rats, mice, rabbits, pigs, sheep, and primates have been used as experimental models, and pregnancies were achieved in some of these. Human data consist of 11 subjects yielding positive pregnancy results with no live births in the second trial from Turkey and, more fortunately, live births from the latest trial from Sweden. In the light of all these studies, uterus transplantation has been proven to be a viable option for women with uterine factor infertility.

  11. How random is your heart beat?

    CERN Document Server

    Urbanowicz, K; Holyst, J A; Zebrowski, J J

    2006-01-01

    We measure the content of random uncorrelated noise in heart rate variability using a general method of noise level estimation using a coarse grained entropy. We show that usually - except for atrial fibrillation - the level of such noise is within 5 - 15% of the variance of the data and that the variability due to the linearly correlated processes is dominant in all cases analysed but atrial fibrillation. The nonlinear deterministic content of heart rate variability remains significant and may not be ignored.

  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. 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.

  14. 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.

  15. 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.

  16. Epicardial radiofrequency ablation on a beating heart: an experimental study.

    Science.gov (United States)

    Ishikawa, Susumu; Oki, Shigeru; Muraoka, Masato; Oshima, Kiyohiro; Kashiwabara, Kenji; Morishita, Yasuo

    2005-02-01

    The effect of epicardial radiofrequency ablation (RFA) during normal heart beating was experimentally studied in order to establish safe and effective procedures for RFA. Seven pigs weighing approximately 30 to 50 kg were used in this study. Fifty-one epicardial RFA lesions were created on both atria using a Cobra Cooled probe with continuous internal irrigation of a saline solution. The ablation temperature was fixed at 80 degrees C and the duration of the RFA in each case was 20, 30, 60 and 120 seconds. There was significant positive correlation between the right and left atria in wall thickness. Transmural coagulation was obtained in 69% of the total specimens, which decreased according to the increase of wall thickness especially over 3 mm. Transmural coagulation was seen in 64% of the specimens after RFA of less than 30 seconds, and 86% after ablation of >or=60 seconds. Occurence of 90% or deeper coagulation was higher in the right atrium than in the left one (97% vs. 78%). Right atrial rupture occurred in a region of 1 mm in thickness after ablation of 60 seconds. Further technical improvements associated with new instruments are indispensable to complete epicardial RFA procedures on a beating heart.

  17. 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

    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

  18. Synchronization using environmental coupling in mercury beating heart oscillators

    Science.gov (United States)

    Singla, Tanu; Montoya, Fernando; Rivera, M.; Tajima, Shunsuke; Nakabayashi, Seiichiro; Parmananda, P.

    2016-06-01

    We report synchronization of Mercury Beating Heart (MBH) oscillators using the environmental coupling mechanism. This mechanism involves interaction of the oscillators with a common medium/environment such that the oscillators do not interact among themselves. In the present work, we chose a modified MBH system as the common environment. In the absence of coupling, this modified system does not exhibit self sustained oscillations. It was observed that, as a result of the coupling of the MBH oscillators with this common environment, the electrical and the mechanical activities of both the oscillators synchronized simultaneously. Experimental results indicate the emergence of both lag and the complete synchronization in the MBH oscillators. Simulations of the phase oscillators were carried out in order to better understand the experimental observations.

  19. Heart-Rate Variability—More than Heart Beats?

    Directory of Open Access Journals (Sweden)

    Gernot Ernst

    2017-09-01

    Full Text Available Heart-rate variability (HRV is frequently introduced as mirroring imbalances within the autonomous nerve system. Many investigations are based on the paradigm that increased sympathetic tone is associated with decreased parasympathetic tone and vice versa. But HRV is probably more than an indicator for probable disturbances in the autonomous system. Some perturbations trigger not reciprocal, but parallel changes of vagal and sympathetic nerve activity. HRV has also been considered as a surrogate parameter of the complex interaction between brain and cardiovascular system. Systems biology is an inter-disciplinary field of study focusing on complex interactions within biological systems like the cardiovascular system, with the help of computational models and time series analysis, beyond others. Time series are considered surrogates of the particular system, reflecting robustness or fragility. Increased variability is usually seen as associated with a good health condition, whereas lowered variability might signify pathological changes. This might explain why lower HRV parameters were related to decreased life expectancy in several studies. Newer integrating theories have been proposed. According to them, HRV reflects as much the state of the heart as the state of the brain. The polyvagal theory suggests that the physiological state dictates the range of behavior and psychological experience. Stressful events perpetuate the rhythms of autonomic states, and subsequently, behaviors. Reduced variability will according to this theory not only be a surrogate but represent a fundamental homeostasis mechanism in a pathological state. The neurovisceral integration model proposes that cardiac vagal tone, described in HRV beyond others as HF-index, can mirror the functional balance of the neural networks implicated in emotion–cognition interactions. Both recent models represent a more holistic approach to understanding the significance of HRV.

  20. Respiratory sinus arrhythmia during anaesthesia: assessment of respiration related beat-to-beat heart rate variability analysis methods.

    Science.gov (United States)

    Loula, P; Jäntti, V; Yli-Hankala, A

    1997-11-01

    Beat-to-beat heart rate variability analysis is a powerful tool for the diagnosis of neuropathy. Respiration-related heart rate variability (respiratory sinus arrhythmia, RSA) reflects the function of parasympathetic nervous system during spontaneous ventilation while awake. RSA is also claimed to monitor the depth of anaesthesia. Power spectrum analysis or various averaging techniques of the heart rate variability are usually applied. The current literature, however, does not usually interpret the ground rules and limitations of the method used, and this may sometimes lead to erroneous conclusions on the data. The aim of our study was to compare and analyse critically the performance of different methods of evaluating RSA during anaesthesia and positive pressure ventilation. Power spectrum analysis, the root mean square of the successive RR-interval difference (RMSSD), and two respiration related methods, RSA index and average phase RSA, were included in the comparison. To test these methods, 11 patients were anaesthetised with isoflurane and their lungs were ventilated mechanically with a frequency of 6 cycles min-1. Each patient received a bolus dose of atropine (20 micrograms kg-1) during the trial. Electrocardiogram, electroencephalogram and tracheal pressure signal from respirator were recorded and analyses were performed off-line. We demonstrated that general indices, such as RMSSD, may be strongly affected by heart rate level and other non-respiration related variations in heart rate. We also showed that the effect of unwanted fluctuations on RSA can be reduced with respiration dependent beat-to-beat methods. Furthermore we confirmed that in addition to the amplitude, also the pattern of respiratory sinus arrhythmia is of interest: the pattern is reversed in phase compared to spontaneous breathing while awake, as we have shown earlier. To analyse RSA during anaesthesia, we recommend the use of an average phase RSA method based on beat-to-beat variability

  1. Heart Motion Prediction Based on Adaptive Estimation Algorithms for Robotic Assisted Beating Heart Surgery

    Science.gov (United States)

    Tuna, E. Erdem; Franke, Timothy J.; Bebek, Özkan; Shiose, Akira; Fukamachi, Kiyotaka; Çavuşoğlu, M. Cenk

    2013-01-01

    Robotic assisted beating heart surgery aims to allow surgeons to operate on a beating heart without stabilizers as if the heart is stationary. The robot actively cancels heart motion by closely following a point of interest (POI) on the heart surface—a process called Active Relative Motion Canceling (ARMC). Due to the high bandwidth of the POI motion, it is necessary to supply the controller with an estimate of the immediate future of the POI motion over a prediction horizon in order to achieve sufficient tracking accuracy. In this paper, two least-square based prediction algorithms, using an adaptive filter to generate future position estimates, are implemented and studied. The first method assumes a linear system relation between the consecutive samples in the prediction horizon. On the contrary, the second method performs this parametrization independently for each point over the whole the horizon. The effects of predictor parameters and variations in heart rate on tracking performance are studied with constant and varying heart rate data. The predictors are evaluated using a 3 degrees of freedom test-bed and prerecorded in-vivo motion data. Then, the one-step prediction and tracking performances of the presented approaches are compared with an Extended Kalman Filter predictor. Finally, the essential features of the proposed prediction algorithms are summarized. PMID:23976889

  2. Microwave radiation and heart-beat rate of rabbits.

    Science.gov (United States)

    Chou, C K; Han, L F; Guy, A W

    1980-06-01

    Each of three adult New Zealand rabbits, 2 male and 1 female albinos, was exposed dorsally or ventrally, to 2450-MHz plane waves for 20 min under each of several field conditions: 1) to continuous waves (CW) at 5 mW/cm2; 2) to pulsed waves (PW) of 1-microsecond width that recurred 700 pps at an average of 5 mW/cm2 and at a peak of 7.1 W/cm2; 3) to PW of 10-microseconds width at a peak of 13.7 W/cm2 that were synchronized with and triggered by the R wave of the electrocardiogram (EKG) at various delay times (0, 100, and 200 ms; and 4) to CW at 80 mW/cm2. Carbon-loaded Teflon electrodes were used to record the EKG from forelimbs of an animal before, during, and after irradiation whilst it was maintained in a constant exposure geometry in a wooden squeeze box. Field induced changes in the heart-beat rate were observed at 80 mW/cm2 but not a lower average power densities, although a peak positive chronotropic effect might have been occasioned by PM introduced at 100 and 200 ms after the R wave peak. No cumulative effect was observed over a period of four months. Thermographic analysis revealed relatively little absorption of microwave energy by the myocardium irrespective of anatomical aspect of exposure.

  3. Aortic and mitral valve surgery on the beating heart is lowering cardiopulmonary bypass and aortic cross clamp time.

    Science.gov (United States)

    Gersak, Borut; Sutlic, Zeljko

    2002-01-01

    the selected high risk patients or to minimize the deleterious effects of cardiopulmonary bypass (CPB) on the overall postoperative performance [Calafiore 1996, Tasdemir 1998]. Due to the fact, that the cardiac muscle should be protected at most during the cardiac arrest, retrograde blood cardioplegia was successfully introduced [Buckberg 1990], and more - the warm cardioplegia is being used recently [Kawasuji 1997]. The natural status of the human heart is the beating status, so it is reasonable to try to perform the operations on the beating heart. This has been done recently with the MID - CAB and OP - CAB (off-pump CABG) operations [Tasdemir 1998]. The retrograde warm blood cardioplegia has therefore led us to the premise, that with retrograde oxygenated blood perfusion it would be possible to achieve the operations on the beating heart even in the open heart surgery, such as aortic and/or mitral valve surgery. All will agree that the most damaging effect of the cardioplegia is the reperfusion injury [Allen 1997], and it is obvious that with the technique of retrograde continuous oxygenated blood perfusion this effect will be canceled. In this article, we would like to show the how-to technique for the operations on the beating heart in the case of operations on the aortic valve replacement (AVR) with mitral valve repair (MVR) or replacement MVR and with/without concomitant coronary artery bypass (CABG) surgery. The tricuspid valve repair (PTV) is normally done on the beating heart and there it is realized what problems or technical difficulties may arise during procedures on the mitral valve: the walls of the ventricles are not flattened and the exposure of the mitral valve is challenging task. Furthermore, the free walls of the ventricles with interventricular septum are in the state of the tonus, so every force applied to better expose the aortic or mitral valve is not acceptable

  4. 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.

  5. 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

    2017-09-25

    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.

  6. Influence of microwaves on the beating rate of isolated rat hearts.

    Science.gov (United States)

    Yee, K C; Chou, C K; Guy, A W

    1988-01-01

    Previous reports have shown that microwave exposure can decrease the beating rate of isolated rat hearts. These experiments were conducted at room temperature and with the hearts exposed to air. We observed arrhythmia frequently at room temperature, and the variation of heart beat was so large that it makes the results difficult to reproduce. Therefore, we employed a double-circulating system to provide perfusion through the coronary artery and around the outside of the heart to maintain the rat hearts at 37.7 degrees C. No arrhythmias were observed in our experiments, and the hearts were beating for at least 1 h. The effects of 16-Hz modulated 2,450-MHz pulsed microwaves (10 microseconds, 100 pps) on the beating rate of 50 isolated rat hearts were studied. Results showed no statistically significant changes of heart rate in exposed groups at SARs of 2 and 10 W/kg compared with the control group. The effect seen at 200 W/kg was shown to be similar to that resulting from heating the heart.

  7. Automatic computerized analysis of heart rate variability with digital filtering of ectopic beats.

    Science.gov (United States)

    Storck, N; Ericson, M; Lindblad, L; Jensen-Urstad, M

    2001-01-01

    Analysis of heart rate variability (HRV) has been used in studies of autonomic function and risk assessment in different patient groups such as in patients with diabetes mellitus, after myocardial infarction (MI) and other cardiovascular disease. Ectopic beats can, however, interfere with HRV analysis and give erroneous results. We have therefore studied the impact of ectopic beats on HRV analysis and the ability of a filter algorithm to correct this. Power spectral analysis of synthetic data with an increasing proportion of ectopic beats and 24-h Holter recordings from 98 healthy subjects and 93 post MI patients was done with and without digital filtering and interpolation of errors in the data stream. The analysis of HRV was seriously hampered by less than 1% of ectopic beats. A filter algorithm based on detection and linear interpolation of ectopic beats and other noise in the data stream corrected effectively for this in the synthetic data employed. In the healthy subjects and the post MI patients, filtering markedly reduced the extra variability related to non-normal beats. The software could automatically analyse over one hundred 24-h files in one batch. HRV analysis should include filtering for ectopic beats even with a small number of such beats. It is possible to make a fast analysis automatically even in huge clinical series, which makes it possible to use the method both clinically and in epidemiological studies.

  8. Human auditory steady state responses to binaural and monaural beats.

    Science.gov (United States)

    Schwarz, D W F; Taylor, P

    2005-03-01

    Binaural beat sensations depend upon a central combination of two different temporally encoded tones, separately presented to the two ears. We tested the feasibility to record an auditory steady state evoked response (ASSR) at the binaural beat frequency in order to find a measure for temporal coding of sound in the human EEG. We stimulated each ear with a distinct tone, both differing in frequency by 40Hz, to record a binaural beat ASSR. As control, we evoked a beat ASSR in response to both tones in the same ear. We band-pass filtered the EEG at 40Hz, averaged with respect to stimulus onset and compared ASSR amplitudes and phases, extracted from a sinusoidal non-linear regression fit to a 40Hz period average. A 40Hz binaural beat ASSR was evoked at a low mean stimulus frequency (400Hz) but became undetectable beyond 3kHz. Its amplitude was smaller than that of the acoustic beat ASSR, which was evoked at low and high frequencies. Both ASSR types had maxima at fronto-central leads and displayed a fronto-occipital phase delay of several ms. The dependence of the 40Hz binaural beat ASSR on stimuli at low, temporally coded tone frequencies suggests that it may objectively assess temporal sound coding ability. The phase shift across the electrode array is evidence for more than one origin of the 40Hz oscillations. The binaural beat ASSR is an evoked response, with novel diagnostic potential, to a signal that is not present in the stimulus, but generated within the brain.

  9. A Miniature Mobile Robot for Navigation and Positioning on the Beating Heart

    Science.gov (United States)

    Patronik, Nicholas A.; Ota, Takeyoshi; Zenati, Marco A.; Riviere, Cameron N.

    2010-01-01

    Robotic assistance enhances conventional endoscopy; yet, limitations have hindered its mainstream adoption for cardiac surgery. HeartLander is a miniature mobile robot that addresses several of these limitations by providing precise and stable access over the surface of the beating heart in a less-invasive manner. The robot adheres to the heart and navigates to any desired target in a semiautonomous fashion. The initial therapies considered for HeartLander generally require precise navigation to multiple surface targets for treatment. To balance speed and precision, we decompose any general target acquisition into navigation to the target region followed by fine positioning to each target. In closed-chest, beating-heart animal studies, we demonstrated navigation to targets located around the circumference of the heart, as well as acquisition of target patterns on the anterior and posterior surfaces with an average error of 1.7 mm. The average drift encountered during station-keeping was 0.7 mm. These preclinical results demonstrate the feasibility of precise semiautonomous delivery of therapy to the surface of the beating heart using HeartLander. PMID:20179783

  10. 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.

  11. 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).

  12. Beat-to-beat heart rate and blood pressure variability and hypertensive disease in pregnancy.

    Science.gov (United States)

    Flood, Pamela; McKinley, Paula; Monk, Catherine; Muntner, Paul; Colantonio, Lisandro D; Goetzl, Laura; Hatch, Maureen; Sloan, Richard P

    2015-09-01

    The aim of this study is to determine the relationship between heart rate and/or blood pressure variability, measured at 28 weeks' gestation, and the incidence of pregnancy-induced hypertension or preeclampsia. Secondary analysis of data from a prospectively enrolled cohort of 385 active military women in whom spectral analysis of continuous heart rate and variability was measured at 28 weeks' gestation. The primary outcome was the predictive value of spectral analysis of heart rate and blood pressure for hypertensive diseases of pregnancy. High-frequency heart rate variability was reduced and low-frequency variability of systolic and diastolic blood pressure increased in women who would develop pregnancy-induced hypertension but not preeclampsia. Low-frequency variability of diastolic blood pressure remained a significant predictor of pregnancy-induced hypertension but not preeclampsia after adjustment for age, weight, and blood pressure in a multivariate model. Early identification of pregnancy-induced hypertension can facilitate treatment to avoid maternal morbidity. Understanding the physiological underpinnings of the two very different diseases may lead to improved treatment and prevention. If proven effective in a broader population, the ability to differentiate pregnancy-induced hypertension from preeclampsia may reduce unnecessary iatrogenic interventions or inappropriate preterm delivery. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

  13. Lung Transplantation from Nonheparinized Category III Non-Heart-Beating Donors. A Single-Centre Report

    NARCIS (Netherlands)

    Erasmus, Michiel E.; Verschuuren, Erik A. M.; Nijkamp, Danielle M.; Vermeyden, J. Wytse; van der Bij, Wim

    2010-01-01

    Background. Despite the increasing use of extended lung donors, the shortage of lung donors remains. Usage of non-heart-beating (NHB) lung donors contributes to fight this shortage. We describe our experience in 21 consecutive adult lung transplantations using nonheparinized category III NHB donors

  14. On-pump beating heart coronary revascularization: Is it valid for emergency revascularization?

    Science.gov (United States)

    Aydin, Ahmet; Erkut, Bilgehan

    2015-01-01

    On-pump beating heart coronary artery bypass grafting (CABG) may be considered as an alternative to the conventional on-pump surgery in patients presenting with acute coronary syndrome requiring emergency revascularization. This study reports our clinical experience and early outcomes with the on-pump beating heart coronary surgery on patients with acute coronary syndrome. A retrospective study conducted from August 2009 to October 2015, in a regional training and research hospital in Turkey. A total of 1432 patients underwent isolated CABG at our institution. A total of 316 of these patients underwent the on-pump beating heart procedure without cardioplegic arrest by the same surgeon. The time interval from the onset of acute myocardial infarction to CABG was 10 (2.2) hours. The mean number of grafts was 3.0 (0.6). Hospital mortality was 2.9% (9 patients). Twelve patients had low cardiac output syndromes after surgery. Eight of them had renal dysfunction but none of them needed hemodialysis. The mean intensive care unit stay was 3 (2) days and the mean hospital length of stay was 7 (4) days. We think that the on-pump beating heart revascularization technique can be a good choice for emergency CABG of high-risk patients with a multivessel coronary artery disease.

  15. 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.

  16. Smith predictor-based robot control for ultrasound-guided teleoperated beating-heart surgery.

    Science.gov (United States)

    Bowthorpe, Meaghan; Tavakoli, Mahdi; Becher, Harald; Howe, Robert

    2014-01-01

    Performing surgery on fast-moving heart structures while the heart is freely beating is next to impossible. Nevertheless, the ability to do this would greatly benefit patients. By controlling a teleoperated robot to continuously follow the heart's motion, the heart can be made to appear stationary. The surgeon will then be able to operate on a seemingly stationary heart when in reality it is freely beating. The heart's motion is measured from ultrasound images and thus involves a non-negligible delay due to image acquisition and processing, estimated to be 150 ms that, if not compensated for, can cause the teleoperated robot's end-effector (i.e., the surgical tool) to collide with and puncture the heart. This research proposes the use of a Smith predictor to compensate for this time delay in calculating the reference position for the teleoperated robot. The results suggest that heart motion tracking is improved as the introduction of the Smith predictor significantly decreases the mean absolute error, which is the error in making the distance between the robot's end-effector and the heart follow the surgeon's motion, and the mean integrated square error.

  17. K channel kinetics during the spontaneous heart beat in embryonic chick ventricle cells.

    OpenAIRE

    Mazzanti, M.; DeFelice, L J

    1988-01-01

    By averaging the current that passes through cell-attached patches on beating heart cells, while measuring action potentials with a whole-cell electrode, we were able to study K channels during beating. In 7-d chick ventricle in 1.3 mM K physiological solutions at room temperature, delayed-rectifier channels have three linear conductance states: 60, 30, and 15 pS. The 60 and 15 pS conductances can exist alone, but all three states may appear in the same patch as interconverting conductance le...

  18. Effect of myocardial protection during beating heart surgery with right sub-axiliary approach

    Institute of Scientific and Technical Information of China (English)

    MA Jie; LI Xin-hua; YAN Zi-xing; LIU Ai-jun; ZHANG Wen-kai; YANG Li-na

    2009-01-01

    Background Cardiac troponin-I (cTnl) is one of the three regulatory subunits of the cardiac troponin which has the high sensibility and specificity of responding to myocardial injury. Studies have demonstrated that cTnl is released into the blood stream within hours following acute myocardial reperfusion injury. The clinical utility of cTnl for the assessment of myocardial damage is that it is more specific than creatine kinase MB (CKMB). This study investigated cTnl as a sensitive marker of myocardial reperfusion injury and its clinical value on beating heart surgery with right sub-axiliary incision. Methods From December 2002 threugh December 2004,100 patients with atrial septal defect (ASD), ventricular septal defect (VSD), atrial septal defect and ventricular septal defect (ASD+VSD), and tetralogy of Fallot were randomly divided into two groups: the treatment group (n=50) was operated on with a beating heart under extracorporeal circulation (ECC), and the control group (n=50) on an conventional arresting heart under ECC. The two groups both used a right sub-axillary incision. Blood samples from a central venous catheter (CVC) were collected before, at the end of aortic clamping, immediately after discontinue cardiopulmonary bypass (CPB), 3, 6, 24, and 48 hours after operation. The Abbott Axsym system with hol-automation fluorescent immunity analyzer was used for the quantitative determination of cTnl. cTnl was detected to investigate the effect of myocardial ischemia reperfusion injury and the clinical value of beating heart surgery with right sub-axillary incision. Results There were no significant differences between the two groups before operation. At the end of aortic clamping and thereafter, cTnl significantly increased in both groups, and reached the peak point at 6 hours after operation. At all the tested points, cTnl was significantly higher in the control group than the beating heart group (P <0.05), especially at 6 hours post operation (P <0.01). The

  19. Neuro-adaptive control in beating heart surgery based on the viscoelastic tissue model

    Directory of Open Access Journals (Sweden)

    Setareh Rezakhani

    2014-04-01

    Full Text Available In this paper, the problem of 3D heart motion in beating heart surgery is resolved by proposing a parallel force-motion controller. Motion controller is designed based on neuro-adaptive approach to compensate 3D heart motion and deal with uncertainity in dynamic parameters, while an implicit force control is implemented by considering a viscoelastic tissue model. Stability analysis is proved through Lypanov’s stability theory and Barballet’s lemma. Simulation results, for D2M2 robot, which is done in nominal case and viscoelastic parameter mismatches demonstrate the robust performance of the controller.

  20. 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.

  1. Moving to the Beat and Singing are Linked in Humans

    Science.gov (United States)

    Dalla Bella, Simone; Berkowska, Magdalena; Sowiński, Jakub

    2015-01-01

    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 less accurate and less precise 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. PMID:26733370

  2. Human induced pluripotent stem cell-derived beating cardiac tissues on paper.

    Science.gov (United States)

    Wang, Li; Xu, Cong; Zhu, Yujuan; Yu, Yue; Sun, Ning; Zhang, Xiaoqing; Feng, Ke; Qin, Jianhua

    2015-11-21

    There is a growing interest in using paper as a biomaterial scaffold for cell-based applications. In this study, we made the first attempt to fabricate a paper-based array for the culture, proliferation, and direct differentiation of human induced pluripotent stem cells (hiPSCs) into functional beating cardiac tissues and create "a beating heart on paper." This array was simply constructed by binding a cured multi-well polydimethylsiloxane (PDMS) mold with common, commercially available paper substrates. Three types of paper material (print paper, chromatography paper and nitrocellulose membrane) were tested for adhesion, proliferation and differentiation of human-derived iPSCs. We found that hiPSCs grew well on these paper substrates, presenting a three-dimensional (3D)-like morphology with a pluripotent property. The direct differentiation of human iPSCs into functional cardiac tissues on paper was also achieved using our modified differentiation approach. The cardiac tissue retained its functional activities on the coated print paper and chromatography paper with a beating frequency of 40-70 beats per min for up to three months. Interestingly, human iPSCs could be differentiated into retinal pigment epithelium on nitrocellulose membrane under the conditions of cardiac-specific induction, indicating the potential roles of material properties and mechanical cues that are involved in regulating stem cell differentiation. Taken together, these results suggest that different grades of paper could offer great opportunities as bioactive, low-cost, and 3D in vitro platforms for stem cell-based high-throughput drug testing at the tissue/organ level and for tissue engineering applications.

  3. Beating heart on a chip: a novel microfluidic platform to generate functional 3D cardiac microtissues.

    Science.gov (United States)

    Marsano, Anna; Conficconi, Chiara; Lemme, Marta; Occhetta, Paola; Gaudiello, Emanuele; Votta, Emiliano; Cerino, Giulia; Redaelli, Alberto; Rasponi, Marco

    2016-02-07

    In the past few years, microfluidic-based technology has developed microscale models recapitulating key physical and biological cues typical of the native myocardium. However, the application of controlled physiological uniaxial cyclic strains on a defined three-dimension cellular environment is not yet possible. Two-dimension mechanical stimulation was particularly investigated, neglecting the complex three-dimensional cell-cell and cell-matrix interactions. For this purpose, we developed a heart-on-a-chip platform, which recapitulates the physiologic mechanical environment experienced by cells in the native myocardium. The device includes an array of hanging posts to confine cell-laden gels, and a pneumatic actuation system to induce homogeneous uniaxial cyclic strains to the 3D cell constructs during culture. The device was used to generate mature and highly functional micro-engineered cardiac tissues (μECTs), from both neonatal rat and human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CM), strongly suggesting the robustness of our engineered cardiac micro-niche. Our results demonstrated that the cyclic strain was effectively highly uniaxial and uniformly transferred to cells in culture. As compared to control, stimulated μECTs showed superior cardiac differentiation, as well as electrical and mechanical coupling, owing to a remarkable increase in junction complexes. Mechanical stimulation also promoted early spontaneous synchronous beating and better contractile capability in response to electric pacing. Pacing analyses of hiPSC-CM constructs upon controlled administration of isoprenaline showed further promising applications of our platform in drug discovery, delivery and toxicology fields. The proposed heart-on-a-chip device represents a relevant step forward in the field, providing a standard functional three-dimensional cardiac model to possibly predict signs of hypertrophic changes in cardiac phenotype by mechanical and biochemical co-stimulation.

  4. 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.

  5. Prevention of adenosine A2A receptor activation diminishes beat-to-beat alternation in human atrial myocytes.

    Science.gov (United States)

    Molina, Cristina E; Llach, Anna; Herraiz-Martínez, Adela; Tarifa, Carmen; Barriga, Montserrat; Wiegerinck, Rob F; Fernandes, Jacqueline; Cabello, Nuria; Vallmitjana, Alex; Benitéz, Raúl; Montiel, José; Cinca, Juan; Hove-Madsen, Leif

    2016-01-01

    Atrial fibrillation (AF) has been associated with increased spontaneous calcium release from the sarcoplasmic reticulum and linked to increased adenosine A2A receptor (A2AR) expression and activation. Here we tested whether this may favor atrial arrhythmogenesis by promoting beat-to-beat alternation and irregularity. Patch-clamp and confocal calcium imaging was used to measure the beat-to-beat response of the calcium current and transient in human atrial myocytes. Responses were classified as uniform, alternating or irregular and stimulation of Gs-protein coupled receptors decreased the frequency where a uniform response could be maintained from 1.0 ± 0.1 to 0.6 ± 0.1 Hz; p < 0.01 for beta-adrenergic receptors and from 1.4 ± 0.1 to 0.5 ± 0.1 Hz; p < 0.05 for A2ARs. The latter was linked to increased spontaneous calcium release and after-depolarizations. Moreover, A2AR activation increased the fraction of non-uniformly responding cells in HL-1 myocyte cultures from 19 ± 3 to 51 ± 9 %; p < 0.02, and electrical mapping in perfused porcine atria revealed that adenosine induced electrical alternans at longer cycle lengths, doubled the fraction of electrodes showing alternation, and increased the amplitude of alternations. Importantly, protein kinase A inhibition increased the highest frequency where uniform responses could be maintained from 0.84 ± 0.12 to 1.86 ± 0.11 Hz; p < 0.001 and prevention of A2AR-activation with exogenous adenosine deaminase selectively increased the threshold from 0.8 ± 0.1 to 1.2 ± 0.1 Hz; p = 0.001 in myocytes from patients with AF. In conclusion, A2AR-activation promotes beat-to-beat irregularities in the calcium transient in human atrial myocytes, and prevention of A2AR activation may be a novel means to maintain uniform beat-to-beat responses at higher beating frequencies in patients with atrial fibrillation.

  6. Effects of beating-heart and arrested heart intracardiac procedure on the inflammation induced by cardiopulmonary bypass

    Institute of Scientific and Technical Information of China (English)

    ZHANG Zhe; XIAO Ying-Bin; CHEN Lin; WANG Xue-feng; ZHONG Qian-jin

    2005-01-01

    Objective:To evaluate the effects of beating-heart and arrested heart intracardiac procedure on the expression of tumor necrosis factor alpha (TNF-α) mRNA in myocardium.Methods: Thirty congenital ventricular septal defect (VSD) patients aged from 5 to 10 years old were randomly divided into 2 groups equally. Group A underwent traditional arrested-heart intracardiac procedures; group B underwent beating-heart procedures. Specimens of myocardium were obtained at the onset (baseline) and the end of cardiopulmonary bypass (CPB) for the determination of TNF-α mRNA. Concentration of TNF-α was respectively measured after anesthetic induction (T1), 20 min after the beginning of CPB (T2), at the end of CPB (T3) and 6, 12, 24 h after CPB (T4-6) in all patients. After separating polymorphonuclear leucocyte (PMN), we distilled nuclear protein and mensurated the activation of nuclear factor-κB (NF-κB) by electrophoretic mobility shift assay (EMSA). Results:Compared with baseline, the expression of TNF-α mRNA significantly increased in both groups (P<0.05). TNF-α mRNA level of group A was significantly higher than that of group B at the end of CPB (P<0.05). The plasma concentration of TNF-α and neutrophil NF-κB activity in group A was significantly higher than that of group B at T4-6 (P<0.05). Conclusion:Compared with traditional arrested CPB, beating heart intracadiac procedure can effectively reduce the expression and release of TNF-α; it will benefit the protection of pediatric myocardial during CPB.

  7. Comparative usefulness of beat-to-beat QT dispersion and QT interval fluctuations for identifying patients with organic heart disease at risk for ventricular arrhythmias.

    Science.gov (United States)

    Galeano, Erdulfo J; Yoshida, Akihiro; Ohnishi, Yoshio; Okajima, Katsunori; Ishida, Akihiko; Kitamura, Hidetsuna; Kubo, Shinya; Yokoyama, Mitsuhiro

    2003-02-01

    The comparative usefulness of 10 min of beat-to-beat 12-lead QT dispersion (QTd) and QT interval variability index (QTVI) analysis for identifying patients with organic heart disease (OHD) at risk for ventricular arrhythmias was assessed in 86 subjects: 54 had OHD without a history of ventricular arrhythmias, 15 had OHD with documented ventricular tachycardia, and there were 17 controls. The following parameters were analyzed among the groups: (1) the average QTd (mean QTd), (2) the difference between the maximum and minimum QTd observed over the recording time (QTd variation), (3) the maximum difference of QTd between consecutive beats (QTd maximum), (4) the QTd standard deviation (QTd variability), and (5) QTVI, calculated in lead I or II according to an established formula: log 10 [(QTv/QTm2) / (HRv/HRm2)]. All the analyzed parameters were significantly increased in the patients with and without ventricular tachycardia when compared with the controls. QTd variation, QTd maximum and QTd variability were the only variables that remained significantly increased in the group of patients with documented ventricular tachycardia, compared with those without arrhythmia. Thus, beat-to-beat fluctuations of both the QT interval and QTd may be markers of temporal electrical instability in patients with OHD.

  8. 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.

  9. Frank-Starling mechanism retains recirculation fraction of myocardial Ca(2+) in the beating heart.

    Science.gov (United States)

    Mizuno, J; Araki, J; Mohri, S; Minami, H; Doi, Y; Fujinaka, W; Miyaji, K; Kiyooka, T; Oshima, Y; Iribe, G; Hirakawa, M; Suga, H

    2001-12-01

    Myocardial Ca(2+) handling in excitation-contraction coupling is the second primary determinant of energy or O(2) demand in a working heart. The intracellular and extracellular routes remove myocardial Ca(2+) that was released into the sarcoplasma with different Ca(2+): ATP stoichiometries. The intracellular route is twice as economical as the extracellular route. Therefore the fraction of total Ca(2+) removed via the sarcoplasmic reticulum, i.e., the recirculation fraction of intracellular Ca(2+) (RF), determines the economy of myocardial Ca(2+) handling. RF has conventionally been estimated as the exponential decay rate of postextrasystolic potentiation (PESP). However, we have found that PESP usually decays in alternans, but not exponentially in the canine left ventricle beating above 100 beats/min. We have succeeded in estimating RF from the exponential decay component of an alternans PESP. We previously found that the Frank-Starling mechanism or varied ventricular preload did not affect the economy of myocardial Ca(2+) handling. Then, to account for this important finding, we hypothesized that the Frank-Starling mechanism would not affect RF at a constant heart rate. We tested this hypothesis and found its supportive evidence in 11 canine left ventricles. We conclude that RF at a constant heart rate would remain constant, independent of the Frank-Starling mechanism.

  10. Early feasibility testing and engineering development of a sutureless beating heart connector for left ventricular assist devices.

    Science.gov (United States)

    Koenig, Steven C; Jimenez, Jorge H; West, Seth D; Sobieski, Michael A; Choi, Young; Monreal, Gretel; Giridharan, Guruprasad A; Soucy, Kevin G; Slaughter, Mark S

    2014-01-01

    APK Advanced Medical Technologies (Atlanta, GA) is developing a sutureless beating heart (SBH) left ventricular assist device (LVAD) connector system consisting of anchoring titanium coil, titanium cannula with integrated silicone hemostatic valve, coring and delivery tool, and LVAD locking mechanism to facilitate LVAD inflow surgical procedures. Feasibility testing was completed in human cadavers (n = 4) under simulated normal and hypertensive conditions using saline to observe seal quality in degraded human tissue and assess anatomic fit; acutely in ischemic heart failure bovine model (n = 2) to investigate short-term performance and ease of use; and chronically for 30 days in healthy calves (n = 2) implanted with HeartWare HVAD to evaluate performance and biocompatibility. Complete hemostasis was achieved in human cadavers and animals at LV pressures up to 170 mm Hg. In animals, off-pump (no cardiopulmonary bypass) anchoring of the connector was accomplished in less than 1 minute with no residual bleeding after full delivery and locking of the LVAD; and implant of connector and LVAD were successfully completed in under 10 minutes with total procedure blood loss less than 100 ml. In chronic animals before necropsy, no signs of leakage or disruption at the attachment site were observed at systolic LV pressures >200 mm Hg.

  11. Beating Heart Mitral Valve Replacement Surgery without Aortic Cross-Clamping via Right Thoracotomy in a Patient with Compromised Left Ventricular Functions

    Directory of Open Access Journals (Sweden)

    Ahmet Baris-Durukan

    2015-10-01

    Full Text Available Global myocardial ischemia and ischemia-reperfusion injury are potential adverse events related with cardioplegic arrest. Beating heart surgery has avoided such complications and adapted to valve surgery following successful results published on myocardial revascularization. Difficulty in weaning from cardiopulmonary bypass may be lessened by using on-pump beating heart surgery for mitral valve interventions. Here we describe a 64-year-old male patient with severe mitral regurgitation and dilated cardiomyopathy. Beating heart mitral valve replacement surgery was performed without aortic cross-clamping through a right thoracotomy approach. We believe that, particularly in patients with poor left ventricular functions, beating heart mitral valve surgery may be advantageous

  12. First in vivo traveling wave magnetic particle imaging of a beating mouse heart

    Science.gov (United States)

    Vogel, P.; Rückert, M. A.; Klauer, P.; Kullmann, W. H.; Jakob, P. M.; Behr, V. C.

    2016-09-01

    Magnetic particle imaging (MPI) is a non-invasive imaging modality for direct detection of superparamagnetic iron-oxide nanoparticles based on the nonlinear magnetization response of magnetic materials to alternating magnetic fields. This highly sensitive and rapid method allows both a quantitative and a qualitative analysis of the measured signal. Since the first publication of MPI in 2005 several different scanner concepts have been presented and in 2009 the first in vivo imaging results of a beating mouse heart were shown. However, since the field of view (FOV) of the first MPI-scanner only covers a small region several approaches and hardware enhancements were presented to overcome this issue and could increase the FOV on cost of acquisition speed. In 2014 an alternative scanner concept, the traveling wave MPI (TWMPI), was presented, which allows scanning an entire mouse-sized volume at once. In this paper the first in vivo imaging results using the TWMPI system are presented. By optimizing the trajectory the temporal resolution is sufficiently high to resolve the dynamic of a beating mouse heart.

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

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    Gert Jan Pelgrim

    2015-01-01

    Full Text Available 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 parameters like blood flow, aortic pressure, and heart rate were monitored throughout the experiment. Stenosis was induced in the circumflex artery, controlled by a fractional flow reserve (FFR pressure wire. CT-derived myocardial perfusion parameters were analysed at FFR of 1 to 0.10/0.0. Results. CT images did not show major artefacts due to interference of the model setup. The pacemaker-induced heart rhythm was generally stable at 70 beats per minute. During most of the experiment, blood flow was 0.9–1.0 L/min, and arterial pressure varied between 80 and 95 mm/Hg. Blood flow decreased and arterial pressure increased by approximately 10% after inducing a stenosis with FFR ≤ 0.50. Dynamic perfusion scanning was possible across the range of stenosis grades. Perfusion parameters of circumflex-perfused myocardial segments were affected at increasing stenosis grades. Conclusion. An adapted Langendorff porcine heart model is feasible in a CT environment. This model provides control over physiological parameters and may allow in-depth validation of quantitative CT perfusion techniques.

  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. 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...... diminished reserve and larger propensity for repolarization-dependent ventricular arrhythmia. A subset of chronic AVB dogs (10%) suffers sudden cardiac death (SCD). With the assumption that repolarization defects constitute a potentially lethal proarrhythmic substrate, we hypothesized that BVR in SCD dogs...... are larger than in matched control chronic AVB dogs. From a population of 200 chronic AVB dogs, initially two groups were chosen retrospectively: 8 dogs that died suddenly (SCD) and 8 control dogs. Control dogs had a longer lifespan after AVB (10 to 18 weeks) than SCD dogs (5 to 10 weeks). All dogs had...

  16. Are we ready to utilize non-heart-beating donors for clinical allotransplantation in China?

    Science.gov (United States)

    Liu, Z; Zhu, B; Yun, P; Wang, P; Wang, X; Xu, H

    2008-05-01

    The concept of brain death has not been accepted by the majority of Chinese. Importantly, it is not recognized as a legal entity. We have developed a non-heart-beating donation protocol based on literature searches (Medline, Ovid, and CNKI) and issues related to Chinese customs and ethics. The principles guiding protocol development included: separation of the decision to terminate life support from the donation decision, family-centered donation, freedom of conflict interest, and prohibition of organ sales. This protocol covers donation policy, potential donor identification and evaluation, family consent, determination of death, procurement, and special legal documents/organ distribution policy. A random survey was performed regarding donation. There have been several arguments about the development of this protocol. First, do donor family members have the right to make a decision to withdraw life support? Another issue is whether family members have the right to consent to donation without a will from the donor. Our survey found that over 96.1% of people do not have a will and have not discussed their interests in donation with family members. The last issue is whether the hospital can financially help for the funeral after donation. We have debated these issues nationwide with various opinions. We hope to find the right solutions through international debate. We believe that the use of non-heart-beating-donor organs has potential in China. We are hopeful that it will become a major organ source that is developed in such a way so as to be accepted internationally as well as in China.

  17. "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…

  18. "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…

  19. 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.

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

    Institute of Scientific and Technical Information of China (English)

    Feng WEN; Fang-tian HE

    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.

  1. 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.

  2. 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.

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

    Science.gov (United States)

    Akselrod, Solange; Gordon, David; Ubel, F. Andrew; Shannon, Daniel C.; Barger, A. Clifford; Cohen, Richard J.

    1981-07-01

    Power spectrum analysis of heart rate fluctuations provides a quantitative noninvasive means of assessing the functioning of the short-term cardiovascular control systems. We show that sympathetic and parasympathetic nervous activity make frequency-specific contributions to the heart rate power spectrum, and that renin-angiotensin system activity strongly modulates the amplitude of the spectral peak located at 0.04 hertz. Our data therefore provide evidence that the reninangiotensin system plays a significant role in short-term cardiovascular control on the time scale of seconds to minutes.

  4. From cardiac tissue engineering to heart-on-a-chip: beating challenges.

    Science.gov (United States)

    Zhang, Yu Shrike; Aleman, Julio; Arneri, Andrea; Bersini, Simone; Piraino, Francesco; Shin, Su Ryon; Dokmeci, Mehmet Remzi; Khademhosseini, Ali

    2015-06-11

    The heart is one of the most vital organs in the human body, which actively pumps the blood through the vascular network to supply nutrients to as well as to extract wastes from all other organs, maintaining the homeostasis of the biological system. Over the past few decades, tremendous efforts have been exerted in engineering functional cardiac tissues for heart regeneration via biomimetic approaches. More recently, progress has been made toward the transformation of knowledge obtained from cardiac tissue engineering to building physiologically relevant microfluidic human heart models (i.e. heart-on-chips) for applications in drug discovery. The advancement in stem cell technologies further provides the opportunity to create personalized in vitro models from cells derived from patients. Here, starting from heart biology, we review recent advances in engineering cardiac tissues and heart-on-a-chip platforms for their use in heart regeneration and cardiotoxic/cardiotherapeutic drug screening, and then briefly conclude with characterization techniques and personalization potential of the cardiac models.

  5. Emergency coronary artery bypass graft surgery for acute coronary syndrome: beating heart versus conventional cardioplegic cardiac arrest strategies.

    Science.gov (United States)

    Rastan, Ardawan Julian; Eckenstein, Judith Isabell; Hentschel, Bettina; Funkat, Anne Kathrin; Gummert, Jan Fritz; Doll, Nicolas; Walther, Thomas; Falk, Volkmar; Mohr, Friedrich Wilhelm

    2006-07-04

    Aim of this study was to compare the outcome of beating heart versus conventional coronary artery bypass graft (CABG) strategies in acute coronary syndromes for emergency indications. 638 consecutive patients with acute coronary syndrome (ACS) receiving emergency CABG surgery via midline sternotomy from January 2000 to September 2005 were evaluated. Propensity score analysis was used to predict the probability of undergoing beating heart (BH) (n=240) versus cardioplegic cardiac arrest (CA) (n=398) strategies. Patients presented with stable hemodynamics (n=531) or in cardiogenic shock (CS) (n=107). Hospital and follow-up outcome was compared by propensity score adjusted multiregression analysis. BH included 116 on-pump and 124 off-pump (OPCAB) procedures. There was a propensity to operate CS patients on the beating heart (multivariate odds ratio [OR], 3.8; P=0.001). Under stable hemodynamics significant predictors for BH selection were logEuroSCORE >20% (OR, 2.05), creatinine >1.8 mg/dL (OR, 4.12), complicated percutaneous coronary intervention (OR, 1.88), ejection fraction coronary syndrome with or without CS.

  6. 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.

  7. A Successful Transplantation from Maastricht Category-4 Non-Heart Beating Donor

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    Veysi BAHADIR

    2015-09-01

    Full Text Available The shortage of available organs is the limiting factor for kidney transplantation (Ktx. One of the strategies to increase access to Ktx is the use of non-heart beating (NHB donors. We herein present a successful Ktx from an NHB (Maastricht Category-4 donor. The donor was a 21-year-old woman who had brain death due to cerebrovascular accident. She had severe hypotension for three hours despite 30 μg/kg/min dopamine infusion, followed by cardio-pulmonary arrest just before the operation began. Cardio-pulmonary resuscitation was consequently initiated and continued during the operation. Donor organ harvesting (hepatectomy and bilateral nephrectomy was performed after direct aortic cannulation. The warm ischemia time was 35 minutes. The recipient was a 54-year-old man who had undergone hemodialysis for four years. There were 3/6 mismatches, and the lymphocyte cross-match was negative. The induction immunosuppressive was anti-thymocyte globulin, followed by tacrolimus/ MMF/steroid after the 12th day. He had delayed graft function and hemodialysis was required at the third and sixth days. The urine output gradually increased and sCr slowly declined afterwards and he discharged with sCr 1.5 mg/dl on the 24th day. At the first year of transplantation, he is in good clinical condition with a stable baseline sCr of 1.5 mg/dl. NHB donors can be an alternative and important source to expand the kidney donation pool, and successful long-term outcomes favor this modality.

  8. Beat Keeping in a Sea Lion As Coupled Oscillation: Implications for Comparative Understanding of Human Rhythm.

    Science.gov (United States)

    Rouse, Andrew A; Cook, Peter F; Large, Edward W; Reichmuth, Colleen

    2016-01-01

    Human capacity for entraining movement to external rhythms-i.e., beat keeping-is ubiquitous, but its evolutionary history and neural underpinnings remain a mystery. Recent findings of entrainment to simple and complex rhythms in non-human animals pave the way for a novel comparative approach to assess the origins and mechanisms of rhythmic behavior. The most reliable non-human beat keeper to date is a California sea lion, Ronan, who was trained to match head movements to isochronous repeating stimuli and showed spontaneous generalization of this ability to novel tempos and to the complex rhythms of music. Does Ronan's performance rely on the same neural mechanisms as human rhythmic behavior? In the current study, we presented Ronan with simple rhythmic stimuli at novel tempos. On some trials, we introduced "perturbations," altering either tempo or phase in the middle of a presentation. Ronan quickly adjusted her behavior following all perturbations, recovering her consistent phase and tempo relationships to the stimulus within a few beats. Ronan's performance was consistent with predictions of mathematical models describing coupled oscillation: a model relying solely on phase coupling strongly matched her behavior, and the model was further improved with the addition of period coupling. These findings are the clearest evidence yet for parity in human and non-human beat keeping and support the view that the human ability to perceive and move in time to rhythm may be rooted in broadly conserved neural mechanisms.

  9. Beat Keeping in a Sea Lion as Coupled Oscillation: Implications for Comparative Understanding of Human Rhythm

    Directory of Open Access Journals (Sweden)

    Andrew A Rouse

    2016-06-01

    Full Text Available Human capacity for entraining movement to external rhythms—i.e., beat keeping—is ubiquitous, but its evolutionary history and neural underpinnings remain a mystery. Recent findings of entrainment to simple and complex rhythms in non-human animals pave the way for a novel comparative approach to assess the origins and mechanisms of rhythmic behavior. The most reliable non-human beat keeper to date is a California sea lion, Ronan, who was trained to match head movements to isochronous repeating stimuli and showed spontaneous generalization of this ability to novel tempos and to the complex rhythms of music. Does Ronan’s performance rely on the same neural mechanisms as human rhythmic behavior? In the current study, we presented Ronan with simple rhythmic stimuli at novel tempos. On some trials, we introduced perturbations, altering either tempo or phase in the middle of a presentation. Ronan quickly adjusted her behavior following all perturbations, recovering her consistent phase and tempo relationships to the stimulus within a few beats. Ronan’s performance was consistent with predictions of mathematical models describing coupled oscillation: a model relying solely on phase coupling strongly matched her behavior, and the model was further improved with the addition of period coupling. These findings are the clearest evidence yet for parity in human and non-human beat keeping and support the view that the human ability to perceive and move in time to rhythm may be rooted in broadly conserved neural mechanisms.

  10. Multifractal heart rate dynamics in human cardiovascular model

    Science.gov (United States)

    Kotani, Kiyoshi; Takamasu, Kiyoshi; Safonov, Leonid; Yamamoto, Yoshiharu

    2003-05-01

    Human cardiovascular and/or cardio-respiratory systems are shown to exhibit both multifractal and synchronous dynamics, and we recently developed a nonlinear, physiologically plausible model for the synchronization between heartbeat and respiration (Kotani, et al. Phys. Rev. E 65: 051923, 2002). By using the same model, we now show the multifractality in the heart rate dynamics. We find that beat-to-beat monofractal noise (fractional Brownian motion) added to the brain stem cardiovascular areas results in significantly broader singularity spectra for heart rate through interactions between sympathetic and parasympathetic nervous systems. We conclude that the model proposed here would be useful in studying the complex cardiovascular and/or cardio- respiratory dynamics in humans.

  11. 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

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

    Science.gov (United States)

    Ferrari, Enrico; Stalder, Nicolas; von Segesser, Ludwig K

    2008-07-02

    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. 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%). 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 implantable cardiac defibrillator. One

  13. Experience of valve replacement under mild hypothermia on pump-beating heart:an analysis of 800 cases

    Institute of Scientific and Technical Information of China (English)

    陈柏成; 肖颖彬; 陈林; 钟前进; 王学锋; 周骐; 易广兵

    2004-01-01

    Objective: To assess the outcome of valve replacement under mild hypothermia on pump-beating heart and to discuss the risk factors of cardiac valve surgery. Methods: In the period from November 1997 to May 2003, a total of 800cases of valve replacement were carried out in our institute. The clinical data were reviewed and the technique of mild hypothermia and pump-beating heart to replace cardiac valve was described in detail. Results: 800 patients, 308 male and 492female, with age range from 8 to 66 years, weighing 19 to 88 kg, underwent operation. The average cardiopulmonary bypass time was (109.38 ± 40.64) min, the average clamping time of the vena cava was (77.87 ± 27.99) min and the average mechanical ventilation time was (17.78 ± 12.21) h. There were 17 patients died in the early postoperative stage with an early mortality rate of 2.13%. The causes of death were failure in the weaning of extracorporeal circulation in 2 cases, severe low output syndrome in 3 cases, ventricular fibrillation in 3 cases, obstruction of coronary ostium of mechanical prosthetic valve in 1 case, hepatic failure in 2 cases, pulmonary failure in 1 case, multiorgan failure in 4 cases, and prosthetic valve dysfunction in 1 case. Severe postopertive complications occurred in 51 cases (6.375%), which included reexploration because of excessive bleeding in 16 cases (2.0%), lavage of poststemal infection in 2 cases (0.25%), postoperative strike in 7 cases (0.875%), pulmonary failure in 5 cases (0.625%), hepatic failure in 4 cases (0.5%), multiorgan failure in 11 cases (1.375 % ), ventricular arrhythmia in 5 cases (0.625%) and peripheral circulation failure in 1 case(0. 125 % ). Conclusion: Mild hypothermia and pump-beating heart result in satisfying clinical outcome in patients undergoing valve replacement. The integrated sequenced deairing procedure ensures the avoidance of air embolism during operation.Pump-beating heart technique offers a safe and practical option especially in

  14. Numerical simulation of hemodynamic changes during beating-heart surgery : Analysis of the effects of cardiac position alteration in an animal model

    NARCIS (Netherlands)

    Ferrari, Gianfranco; De Lazzari, Claudio; de Kroon, Thom L.; Elstrodt, Jan M.; Rakhorst, Gerhard; Gu, Y. John

    2007-01-01

    Hemodynamic instability, mostly due to vertical lifting of the heart, is usually observed during beating-heart surgical procedures. However, some hemodynamic parameters, such as coronary blood flow, are not routinely measured. A digital computer model of the circulation able to simulate and analyze

  15. "Non Working Beating Heart": novo método de proteção miocárdica no transplante cardíaco Non Working Beating Heart: a new strategy of myocardial protection during heart transplant

    Directory of Open Access Journals (Sweden)

    Jarbas Jakson Dinkhuysen

    2011-12-01

    implantation of the donor heart in the bicaval bipulmonary orthotopic position using normothermic beating heart and thus, facilitate the transplanted heart adaptation to the recipient. This study presents a small experience about a new strategy of myocardial protection during heart transplant. METHODS: In cardiopulmonary bypass, the aorta anastomosis was done first, allowing the coronary arteries to receive blood flow and the recovering of the beats. The rest of the anastomosis is performed on a beating heart in sinus rhythm. The pulmonary anastomosis is the last to be done. This methodology was applied in 10 subjects: eight males, age 16-69 (mean 32.7 years, SPAo 90-100 mmHg (mean 96 mmHg, SPAP 25-65 mmHg (mean 46.1 mmHg, PVR 0.9 to 5.0 Wood (mean 3.17 Wood, GTP 4-13 mmHg (mean 7.9 mmHg, and eight male donors, age 15-48 years (mean 27.7 years, weight 65-114 kg (mean 83.1 kg. Causes of brain coma: encephalic trauma in five hemorrhagic stroke in four, and brain tumor in one. RESULTS: The ischemic time ranged from 58-90 minutes (mean 67.6 minutes and 8 donors were in hospitals of Sao Paulo and two in distant cities. All grafts assumed the cardiac output requiring low-dose inotropic therapy and maintained these conditions in the postoperative period. There were no deaths and all were discharged. The late evolution goes from 20 days to 10 months with one death occurred after 4 months due to sepsis. CONCLUSION: This method, besides reducing the ischemic time of the procedure, allows the donated organ to regain and maintain their beats without pre or after load during implantation entailing the physiological recovery of the graft.

  16. Detecting variations of blood volume shift due to heart beat from respiratory inductive plethysmography measurements in man.

    Science.gov (United States)

    Fontecave-Jallon, J; Videlier, B; Baconnier, P; Tanguy, S; Calabrese, P; Guméry, P-Y

    2013-09-01

    The simultaneous study of the cardiac and respiratory activities and their interactions is of great physiological and clinical interest. For this purpose, we want to investigate if respiratory inductive plethysmography (RIP) can be used for cardiac functional exploration. We propose a system, based on RIP technology and time-scale approaches of signal processing, for the extraction of cardiac information. This study focuses on the monitoring of blood volume shift due to heart beat, noted ▵Vtr_c and investigates RIP for the detection of ▵Vtr_c variations by comparison to stroke volume (SV) variations estimated by impedance cardiography (IMP). We proposed a specific respiratory protocol assumed to induce significant variations of the SV. Fifteen healthy volunteers in the seated and supine positions were asked to alternate rest respiration and maneuvers, consisting in blowing into a manometer. A multi-step treatment including a variant of empirical mode decomposition was applied on RIP signals to extract cardiac volume signals and estimate beat-to-beat ▵Vtr_c. These were averaged in quasi-stationary states at rest and during the respiratory maneuvers, and analysed in view of SV estimations from IMP signals simultaneously acquired. Correlation and statistical tests over the data show that RIP can be used to detect variations of the cardiac blood shift in healthy young subjects.

  17. Ciliary beating recovery in deficient human airway epithelial cells after lentivirus ex vivo gene therapy.

    Directory of Open Access Journals (Sweden)

    Brigitte Chhin

    2009-03-01

    Full Text Available Primary Ciliary Dyskinesia is a heterogeneous genetic disease that is characterized by cilia dysfunction of the epithelial cells lining the respiratory tracts, resulting in recurrent respiratory tract infections. Despite lifelong physiological therapy and antibiotics, the lungs of affected patients are progressively destroyed, leading to respiratory insufficiency. Recessive mutations in Dynein Axonemal Intermediate chain type 1 (DNAI1 gene have been described in 10% of cases of Primary Ciliary Dyskinesia. Our goal was to restore normal ciliary beating in DNAI1-deficient human airway epithelial cells. A lentiviral vector based on Simian Immunodeficiency Virus pseudotyped with Vesicular Stomatitis Virus Glycoprotein was used to transduce cultured human airway epithelial cells with a cDNA of DNAI1 driven by the Elongation Factor 1 promoter. Transcription and translation of the transduced gene were tested by RT-PCR and western blot, respectively. Human airway epithelial cells that were DNAI1-deficient due to compound heterozygous mutations, and consequently had immotile cilia and no outer dynein arm, were transduced by the lentivirus. Cilia beating was recorded and electron microscopy of the cilia was performed. Transcription and translation of the transduced DNAI1 gene were detected in human cells treated with the lentivirus. In addition, immotile cilia recovered a normal beat and outer dynein arms reappeared. We demonstrated that it is possible to obtain a normalization of ciliary beat frequency of deficient human airway epithelial cells by using a lentivirus to transduce cells with the therapeutic gene. This preliminary step constitutes a conceptual proof that is indispensable in the perspective of Primary Ciliary Dyskinesia's in vivo gene therapy. This is the first time that recovery of cilia beating is demonstrated in this disease.

  18. Effect of meditation on scaling behavior and complexity of human heart rate variability

    OpenAIRE

    Sarkar, A.; Barat, P.

    2006-01-01

    The heart beat data recorded from samples before and during meditation are analyzed using two different scaling analysis methods. These analyses revealed that mediation severely affects the long range correlation of heart beat of a normal heart. Moreover, it is found that meditation induces periodic behavior in the heart beat. The complexity of the heart rate variability is quantified using multiscale entropy analysis and recurrence analysis. The complexity of the heart beat during mediation ...

  19. Effect of meditation on scaling behavior and complexity of human heart rate variability

    CERN Document Server

    Sarkar, A

    2006-01-01

    The heart beat data recorded from samples before and during meditation are analyzed using two different scaling analysis methods. These analyses revealed that mediation severely affects the long range correlation of heart beat of a normal heart. Moreover, it is found that meditation induces periodic behavior in the heart beat. The complexity of the heart rate variability is quantified using multiscale entropy analysis and recurrence analysis. The complexity of the heart beat during mediation is found to be more.

  20. Comparison of plasma NSE, protein S-100b and EEG changes in traditional arrested-heart procedures and on-pump beating-heart procedures

    Institute of Scientific and Technical Information of China (English)

    王咏; 肖颖彬; 陈林; 王学锋; 钟前进

    2003-01-01

    Objective: To assess the cerebral injury in on-pump beating-heart procedures under mild hypothermia in comparison with traditional on-pump arrested-heart procedures under moderate hypothermia. Methods: Forty patients, 20 with congenital heart disease (CHD) and 20 of rheumatic heart disease (RHD), were divided into 2 groups: Control group (group A, n=20) including 10 patients suffering from CHD as group A1 and the left 10 from RHD as group A2; and experiment group (group B, n=20) which consisting of group B1 (10 with CHD) and group B2 (10 of RHD). The patients in group A underwent traditional arrested-heart procedures, and those in group B were operated on with beating-heart procedures. Arterial blood samples were collected at preoperation (time A), 20 min after cardiopulmonary bypass (CPB) starting (time B), 1 h after CPB (time C) and 24 h postoperation (time D) respectively. Plasma contents of neuron-specific enolase (NSE) and protein S-100b were measured with sensitive ELISA. All the patients received echoencephalography (EEG) before and 1 week after operation. Results: The plasma contents of protein S-100b were increased very significantly at time B, C and D in comparison with those at time A (P<0.01), and that of patients in group A1 was significantly higher than that in group B at time B (P<0.05). There was no significant difference at other time points. At time B, the plasma contents of NSE were significantly higher in group A than in group B, and in group A1 and B1 than in group A2 and B2. What's more, at time B, the former fell back to their preoperative levels, but the latter remained still higher levels than the preoperative ones (P<0.01). No significant difference was found in the abnormality rates of postoperative EEG between 2 groups. Conclusion: The perioperative plasma contents of NSE and protein S-100b are not significantly higher in group B than in group A. On-pump beating-heart procedures do not make more serious cerebral dysfunction than the

  1. Organ bath in detecting the effect of one-hour warm ischemia on pulmonic arteries and bronchi from non-heart-beating donor lungs

    Institute of Scientific and Technical Information of China (English)

    ZHAO Song; WANG Jia-xiang; YANG Yang; HE Zhan-feng; LIAO Qiu-ming

    2009-01-01

    Background Non-heart-beating donor lung has been a promising source of lung transplantation. Many studies on non-heart-beating donor lungs are based on animal lung transplantation. In this study, we assessed by organ bath the effect of one-hour warm ischemia on the non-heart-beating donor lung in terms of the integrity of contractile and relaxant functions and tissue structures of pulmonic arteries and bronchi.Methods Sixteen Swedish pigs were randomly classified into two groups: heart-beating donor group and 1-hour warm ischemia non-heart-beating donor group. Pulmonic and bronchial rings were taken from the isolated left lungs of the pigs. The pulmonic rings were stimulated by U-46619 (5.7 mol/L) and acetylcholine (10~(-4) mmol/L) to assess the contractile abilities of smooth muscle and the endothelium-dependent relaxation response, respectively. As such, acetylcholine (10~(-5) mmol/L) and natrium arachidonic acid (0.01%) were used to detect the contraction of bronchial smooth muscle and epithelium-dependent relaxation response. Meanwhile, the variances of precontraction tension of control groups were recorded to measure whether there was spontaneous relaxation during endothelium/epithelium-dependent relaxation course. Finally, papaverine solution (10~(-4) mmol/L) was used to detect the non-endothelium/epithelium-dependent relaxant abilities of pulmonic and bronchial smooth muscles.Results There was no significant difference in the tension values of precontraction of pulmonic rings (P>0.05), endothelium-dependent relaxation (P>0.05), precontraction of bronchial rings (P>0.05) and epithelium-dependent relaxation (P>0.05) between the heart-beating donor group and the 1-hour warm ischemia non-heart-beating donor group. And the pulmonic and bronchial rings of each subgroup B had no spontaneous relaxation. Finally, papaverine solution relaxed the smooth muscle of all the rings completely.Conclusions The results of this experiment suggest that the contractile

  2. Levonorgestrel decreases cilia beat frequency of human fallopian tubes and rat oviducts without changing morphological structure.

    Science.gov (United States)

    Zhao, Weihong; Zhu, Qian; Yan, Mingxing; Li, Cheng; Yuan, Jiangjing; Qin, Guojuan; Zhang, Jian

    2015-02-01

    Levonorgestrel, a derivative of progesterone, effectively protects women against unwanted pregnancy as an emergency contraceptive. Previous studies have not been successful in determining the mechanism by which levonorgestrel acts. In the present study we analysed cilia beat action and cilia morphology following levonorgestrel exposure in vitro and in vivo using both light and electron microscopy. There was a significant decrease in the ciliary beat frequency (CBF) of human fallopian tubes between mucosal explants bathed in 5 μmol/L levonorgestrel and those bathed in medium alone (P levonorgestrel produced a similar reduction in CBF (~ 10%) compared with the saline control group (P levonorgestrel treatment in either system. Thus, levonorgestrel reduces CBF without damaging cilia morphology. Decreases in CBF may indicate a pathological role for levonorgestrel in the transportation of the ovum and zygote in the fallopian tube.

  3. Preservation of non-heart-beating donor livers in extracorporeal liver perfusion and histidine-trytophan-ketoglutarate solution.

    Science.gov (United States)

    Gong, Jin; Lao, Xue-Jun; Wang, Xi-Mo; Long, Gang; Jiang, Tao; Chen, Shi

    2008-04-21

    To compare the preservation of non-heart-beating donor (NHBD) livers in cold histidine-trytophan-ketoglutarate (HTK) solution and extracorporeal liver perfusion (ECLP). Livers harvested from healthy pigs were stored for 10 h in cold HTK solution (group A, n = 4) or perfused with oxygenated autologous blood at body temperature (group B, n = 4). Both groups were then tested on the circuit for 4 h. Bile production, hemodynamic parameters, hepatocyte markers and reperfusion injury of extracorporeal livers were tested in each group. Liver tissues from each group were examined at the end of reperfusion. At 1, 2, 3 and 4 h after reperfusion, bile production, hemodynamic parameters, hepatocyte markers and reperfusion injury of livers in group A were statistically different from those in group B (P < 0.05 or P < 0.01). ECLP is better than HTK solution to preserve NHBD livers. ECLP can assess the graft viability before liver transplantation.

  4. Common multifractality in the heart rate variability and brain activity of healthy humans

    Science.gov (United States)

    Lin, D. C.; Sharif, A.

    2010-06-01

    The influence from the central nervous system on the human multifractal heart rate variability (HRV) is examined under the autonomic nervous system perturbation induced by the head-up-tilt body maneuver. We conducted the multifractal factorization analysis to factor out the common multifractal factor in the joint fluctuation of the beat-to-beat heart rate and electroencephalography data. Evidence of a central link in the multifractal HRV was found, where the transition towards increased (decreased) HRV multifractal complexity is associated with a stronger (weaker) multifractal correlation between the central and autonomic nervous systems.

  5. General anesthesia suppresses normal heart rate variability in humans

    Science.gov (United States)

    Matchett, Gerald; Wood, Philip

    2014-06-01

    The human heart normally exhibits robust beat-to-beat heart rate variability (HRV). The loss of this variability is associated with pathology, including disease states such as congestive heart failure (CHF). The effect of general anesthesia on intrinsic HRV is unknown. In this prospective, observational study we enrolled 100 human subjects having elective major surgical procedures under general anesthesia. We recorded continuous heart rate data via continuous electrocardiogram before, during, and after anesthesia, and we assessed HRV of the R-R intervals. We assessed HRV using several common metrics including Detrended Fluctuation Analysis (DFA), Multifractal Analysis, and Multiscale Entropy Analysis. Each of these analyses was done in each of the four clinical phases for each study subject over the course of 24 h: Before anesthesia, during anesthesia, early recovery, and late recovery. On average, we observed a loss of variability on the aforementioned metrics that appeared to correspond to the state of general anesthesia. Following the conclusion of anesthesia, most study subjects appeared to regain their normal HRV, although this did not occur immediately. The resumption of normal HRV was especially delayed on DFA. Qualitatively, the reduction in HRV under anesthesia appears similar to the reduction in HRV observed in CHF. These observations will need to be validated in future studies, and the broader clinical implications of these observations, if any, are unknown.

  6. 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 pa

  7. 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.

  8. 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 worko...

  9. On-pump with beating heart or cardioplegic arrest for emergency conversion to cardiopulmonary bypass during off-pump coronary artery bypass.

    Science.gov (United States)

    Yu, Lei; Gu, Tianxiang; Shi, Enyi; Wang, Chun; Fang, Qin; Zhang, Yuhai; Lu, Chunmao

    2014-01-01

    Intraoperative conversion, especially under emergent circumstances during off-pump coronary artery bypass (OPCAB), is associated with a significantly higher rate of hospital mortality. This study compared the clinical early outcomes of patients emergently converting to cardiopulmonary bypass (CPB) with or without cardioplegic arrest and evaluated the efficacy of an on-pump beating heart technique for these critically ill patients. A retrospective study of patients treated at The First Affiliated Hospital of China Medical University over an 8-year period (2005 to 2013). Between January 2005 and September 2013, 104 patients were emergently converted to CPB during OPCAB. In the first 55 patients (53%), the cardioplegic arrest was performed. In the most recent 49 patients (47%), the on-pump beating heart procedure was used without cardioplegic arrest. There were no significant differences in their baseline clinical characteristics, number of anastomoses performed per patient, and reasons for conversions (P > .05). A significant reduction occurred in the observed mortality between the cardioplegic arrest group and the on-pump beating heart group (25.6% vs 6.1%, P=.008). A statistical difference was found between the cardioplegic arrest group and the on-pump beating heart group in the time of CPB, peak cardiac troponin I, duration of inotropic support, time to extubation, intensive care unit stay, postoperative hospital stay, incidence of new intra-aortic balloon pump support, and pulmonary complications (P .05). The on-pump beating heart technique is the preferred method of emergency conversion to CPB during OPCAB. It has lower postoperative mortality and morbidity than the cardioplegic arrest.

  10. 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.

  11. 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

  12. Relation between heart beat fluctuations and cyclic alternating pattern during sleep in insomnia patients.

    Science.gov (United States)

    de Leon-Lomeli, R; Murguia, J S; Chouvarda, I; Mendez, M O; Gonzalez-Galvan, E; Alba, A; Milioli, G; Grassi, A; Terzano, M G; Parrino, L

    2014-01-01

    Insomnia is a condition that affects the nervous and muscular system. Thirty percent of the population between 18 and 60 years suffers from insomnia. The effects of this disorder involve problems such as poor school or job performance and traffic accidents. In addition, patients with insomnia present changes in the cardiac function during sleep. Furthermore, the structure of electroencephalographic A-phases, which builds up the Cyclic Alternating Pattern during sleep, is related to the insomnia events. Therefore, the relationship between these brain activations (A-phases) and the autonomic nervous system would be of interest, revealing the interplay of central and autonomic activity during insomnia. With this goal, a study of the relationship between A-phases and heart rate fluctuations is presented. Polysomnography recording of five healthy subjects, five sleep misperception patients and five patients with psychophysiological insomnia were used in the study. Detrended Fluctuation Analysis (DFA) was used in order to evaluate the heart rate dynamics and this was correlated with the number of A-phases. The results suggest that pathological patients present changes in the dynamics of the heart rate. This is reflected in the modification of A-phases dynamics, which seems to modify of heart rate dynamics.

  13. Microwave Doppler Radar for Heart Beat Detection Versus Electrocardiogram: A Validation Approach

    OpenAIRE

    Obeid, Dany; Sadek, Sawsan; Zaharia, Gheorghe; El Zein, Ghais

    2013-01-01

    International audience; This paper provides a validation approach for a microwave Doppler Radar system used for heartbeat detection. The proposed system is tested at 16 GHz with several transmitted power, simultaneously with a pc-based electrocardiogram. Obtained results show accurate detection for the heartbeat signal in terms of heartbeat rate and heart rate variability.

  14. 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.

  15. Mouse heart rate in a human: diagnostic mystery of an extreme tachyarrhythmia.

    Science.gov (United States)

    Chhabra, Lovely; Goel, Narender; Prajapat, Laxman; Spodick, David H; Goyal, Sanjeev

    2012-01-01

    We report telemetry recording of an extreme non-fatal tachyarrhythmia noted in a hospitalized quadriplegic male with history of atrial fibrillation where the average ventricular conduction rate was found to be about 600 beats per minute and was associated with transient syncope. A medical literature review suggests that the fastest human ventricular conduction rate reported to date in a tachyarrhythmia is 480 beats per minute. We therefore report the fastest human heart rate noted in a tachyarrhythmia and the most probable mechanism of this arrhythmia being a rapid atrial fibrillation with 1:1 conduction in the setting of probable co-existing multiple bypass tracts.

  16. Multiscale analysis of heart beat interval increment series and its clinical significance

    Institute of Scientific and Technical Information of China (English)

    HUANG XiaoLin; NING XinBao; WANG XinLong

    2009-01-01

    Analysis of multiscale entropy (MSE) and multiscale standard deviation (MSD) are performed for both the heart rate interval series and the interval increment series. For the interval series, it is found that, it is impractical to discriminate the diseases of atrial fibrillation (AF) and congestive heart failure (CHF) unambiguously from the healthy. A clear discrimination from the healthy, both young and old, however, can be made in the MSE analysis of the increment series where we find that both CHF and AF sufferers have significantly low MSE values in the whole range of time scales investigated, which reveals that there are common dynamic characteristics underlying these two different diseases. In addition, we propose the sample entropy (SE) corresponding to time scale factor 4 of increment series as a diag-nosis index of both AF and CHF, and the reference threshold is recommended. Further indication that this index can help discriminate sensitively the mild heart failure (cardiac function classes 1 and 2) from the healthy gives a clue to early clinic diagnosis of CHF.

  17. 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...

  18. [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.

  19. Early detection of biliary complications and graft rejection in a non-RH Identitical liver transplant recipient from a non-heart-beating donor: a case report.

    Science.gov (United States)

    Turiño-Luque, J; Zambudio-Carroll, N; Muffak-Granero, K; Villegas-Herrera, T; Garrote-Lara, D; Ferrón-Orihuela, J-A

    2012-09-01

    Because of a shortage of organs, non-heart-beating donors have been proposed to be a possible source of grafts for orthotopic liver transplantation. Herein, we have presented a blood group A+ patient with primary biliary cirrhosis, who underwent orthotopic liver transplantation from a non-heart-beating blood group A- donor. On day 5 after transplantation the patient displayed a low hemoglobin levels as well as an increased total bilirubin with progressive encephalopathy, hypotension, and oligoanuria on day 11. The patient responded to steroid treatment. We assume the main cause of organ dysfunction was a passenger lymphocyte syndrome (ABO-Rh incompatibility). Biliary complications were detected at a 6-month follow-up visit by increased hepatic enzymes. We thus concluded that it is useful to take Rh group into account.

  20. 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.

  1. [IV Consensus meeting of the Spanish Society of Liver Transplantation (SETH) 2012. Liver transplant with non-conventional grafts: Split liver transplantation and non-heart beating donors].

    Science.gov (United States)

    Abradelo, Manuel; Fondevila, Constantino

    2014-03-01

    The disbalance between the number of candidates to liver transplant and the number of liver grafts leads to waiting list mortality. Two potential ways of increasing the number of liver grafts are split liver transplantation and the transplantation of grafts from non-heart beating donors. Both of them were discussed in a consensus meeting of the Spanish Society of Liver Transplantation in October 2012. This paper outlines the conclusions of that meeting.

  2. Finding the beat: From socially coordinated vocalizations in songbirds to rhythmic entrainment in humans.

    Directory of Open Access Journals (Sweden)

    Jonathan Isaac Benichov

    2016-06-01

    Full Text Available Humans and oscine songbirds share the rare capacity for vocal learning. Songbirds have the ability to acquire songs and calls of various rhythms through imitation. In several species, birds can even coordinate the timing of their vocalizations with other individuals in duets that are synchronized with millisecond-accuracy. It is not known, however, if songbirds can perceive rhythms holistically nor if they are capable of spontaneous entrainment to complex rhythms, in a manner similar to humans. Here we review emerging evidence from studies of rhythm generation and vocal coordination across songbirds and humans. In particular, recently developed experimental methods have revealed neural mechanisms underlying the temporal structure of song and have allowed us to test birds’ abilities to predict the timing of rhythmic social signals. Surprisingly, zebra finches can readily learn to anticipate the calls of a vocal robot partner and alter the timing of their answers to avoid jamming, even in reference to complex rhythmic patterns. This capacity resembles, to some extent, human predictive motor response to an external beat. In songbirds, this is driven, at least in part, by the forebrain song system, which controls song timing and is essential for vocal learning. Building upon previous evidence for spontaneous entrainment in human and non-human vocal learners, we propose a comparative framework for future studies aimed at identifying shared mechanism of rhythm production and perception across songbirds and humans.

  3. Heart rate monitoring on the stroke unit. What does heart beat tell about prognosis? An observational study

    Directory of Open Access Journals (Sweden)

    Stypmann Jörg

    2011-04-01

    Full Text Available Abstract Background Guidelines recommend maintaining the heart rate (HR of acute stroke patients within physiological limits; data on the frequency and predictors of significant deviations from these limits are scarce. Methods Demographical data, stroke risk factors, NIH stroke scale score, lesion size and location, and ECG parameters were prospectively assessed in 256 patients with ischemic stroke. Patients were continuously monitored for at least 24 hours on a certified stroke unit. Tachycardia (HR ≥120 bpm and bradycardia (HR Results HR ≥120 bpm occurred in 39 patients (15%. Stroke severity (larger lesion size/higher NIHSS-score on admission, atrial fibrillation and HR on admission predicted its occurrence. HR Conclusions Significant tachycardia and bradycardia are frequent phenomena in acute stroke; however they do not independently predict clinical course or outcome. Continuous monitoring allows detecting rhythm disturbances in stroke patients and allows deciding whether urgent medical treatment is necessary.

  4. 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.

  5. 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...

  6. Transmural Heterogeneity and Remodeling of Ventricular Excitation-Contraction Coupling in Human Heart Failure

    Science.gov (United States)

    Lou, Qing; Fedorov, Vadim V.; Glukhov, Alexey V.; Moazami, Nader; Fast, Vladimir G.; Efimov, Igor R.

    2011-01-01

    Background Excitation-contraction (EC) coupling is altered in the end-stage heart failure (HF). However, spatial heterogeneity of this remodeling has not been established at the tissue level in failing human heart. The objective is to study functional remodeling of EC coupling and calcium handling in failing and nonfailing human hearts. Methods and Results We simultaneously optically mapped action potentials (AP) and calcium transients (CaT) in coronary-perfused left ventricular wedge preparations from nonfailing (n = 6) and failing (n = 5) human hearts. Our major findings are: (1) CaT duration minus AP duration was longer at sub-endocardium in failing compared to nonfailing hearts during bradycardia (40 beats/min). (2) The transmural gradient of CaT duration was significantly smaller in failing hearts compared with nonfailing hearts at fast pacing rates (100 beats/min). (3) CaT in failing hearts had a flattened plateau at the midmyocardium; and exhibited a “two-component” slow rise at sub-endocardium in three failing hearts. (4) CaT relaxation was slower at sub-endocardium than that at sub-epicardium in both groups. Protein expression of sarcoplasmic reticulum Ca2+-ATPase 2a (SERCA2a) was lower at sub-endocardium than that at sub-epicardium in both nonfailing and failing hearts. SERCA2a protein expression at sub-endocardium was lower in hearts with ischemic cardiomyopathy compared with nonischemic cardiomyopathy. Conclusions For the first time, we present direct experimental evidence of transmural heterogeneity of EC coupling and calcium handling in human hearts. End-stage HF is associated with the heterogeneous remodeling of EC coupling and calcium handling. PMID:21502574

  7. [Complete revascularization for multi-vessel coronary diseases through lower ministernotomy on beating heart off-pump surgery].

    Science.gov (United States)

    Xiao, Z B; Zhang, Y; Guo, J Z; Li, Y Y; Zhang, Y P

    2017-06-01

    Objective: To discuss a novel method of complete revascularization for multi-vessel coronary diseases on beating heart off-pump surgery through lower ministernotomy. Methods: Clinical data of 79 patients underwent ministernotomy off-pump coronary artery bypass from January 2015 to May 2016 at Department of Cardiac Surgery, Heart Center, Beijing Friendship Hospital, Capital Medical University were analyzed retrospectively. There were 62 male and 17 female patients, with an average age of (65±9) years. All the patients were multi-vessel coronary diseases and planned to receive coronary artery bypass grafting. Left internal mammary artery, radial artery and great saphenous veins were harvested and prepared, respectively. The perioperative clinical data was observed and collected. Postoperative ventilator-assisted time, intensive care time, and 24-hour thoracic mediastinal drainage volume were recorded. Postoperative cardiac function was evaluated by echocardiography. The data were compared between pre- and post-operative using paired t test. Results: Cardiopulmonary bypass was used in 2 patients during operation because of unstable hemodynamic status, but the incision was not needed to extend for those 2 patients. The lower ministernotomy was converted to traditional full sternotomy in 2 patients due to limited space for proximal anastomosis. In total, 79 patients had an average of (2.8±0.6) grafts. One proximal anastomosis was performed in 75 patients and 2 anastomoses in 4 patients. Distal target vessels consisted of left descending arteries for 79 patients, posterior descending artery for 60 patients, obtuse marginal branch and intermediate branch for 56 patients and diagonal branches for 25 patients, respectively. Average postoperative ventilation time was (19.0±2.2) hours and ICU stay was (60±20) hours. One patient developed postoperative myocardial infarction and needed temporary intra-aortic balloon pump support. One patient was subjected to incision

  8. Analysis of Scalp Potential Activity and Heart Rate Variability during Volitional Control of Heart Beat%意识控制心率过程中头皮脑电活动和心率变异性分析

    Institute of Scientific and Technical Information of China (English)

    于晓琳; 张建保; 王珏

    2009-01-01

    介绍了通过小波包能量和近似熵方法,研究了意识控制心率过程中头皮脑电活动和心率变异性的变化规律.实验结果表明,心率的减慢和加快可以通过意识活动对自主神经的主动调节进行控制,并且脑电活动的变化先于心率的变化.但是,这种控制与运动神经系统不同,因为不同的皮层位置分别与心率的减慢和加快相关联.中央前区与副交感神经活动相关,控制心率减慢,而中央后区与交感神经活动相关,控制心率加快.%In the study the changes of scalp potential and cardiac autonomic nervous system during volitional control of heart beat are explored with the wavelet packet parameters and approximate entropy (ApEn) of Electroencephalogram (EEG) and heart rate variability.The results show that volition can control heart beat and the changes of brain activity are earlier than that of autonomic activity.But its control of heart beat is very different from the motor nervous system because different cortical positions are respectively concerned during the quick and slow control of heart beat.The pre-central areas of brain are correlated with parasympathetic activity by which HR is controlled to slow down.The post-central areas of brain are correlated with sympathetic activity by which HR is controlled to accelerate.

  9. 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.

  10. Beating Heart of Art

    Science.gov (United States)

    Kelin, Daniel A., II

    2015-01-01

    This article presents a critical and comparative look at how two theatre programs help young people develop an artistic voice and sense of self as an artist. Each program begins with art. Individuals explore basic tenets of dramatic expression through foundational activities. As they play and experiment, the individuals discover their capacity for…

  11. Beating Heart of Art

    Science.gov (United States)

    Kelin, Daniel A., II

    2015-01-01

    This article presents a critical and comparative look at how two theatre programs help young people develop an artistic voice and sense of self as an artist. Each program begins with art. Individuals explore basic tenets of dramatic expression through foundational activities. As they play and experiment, the individuals discover their capacity for…

  12. Evaluation on Effects of Donor Heart Preservation for On-Pump Beating-Heart Transplantation%体外循环下不停跳供心保存植入的效果评价▲

    Institute of Scientific and Technical Information of China (English)

    朱蔚琳; 黄爱兰; 胡彦艳; 温红; 林辉; 莫安胜

    2013-01-01

    Objective To study the effects of donor heart preserved with continuous on-pump beating-heart warm-blood perfusion and University of Wisconsin (UW) solution on hemodynamics and cardiac function after transplantation in pigs.Methods Twenty-four Bama miniature pigs were randomly divided into two groups:In beating-heart group (n=12),donor hearts were stored by on-pump perfusion with warm blood;In cold UW storage group (n=12),donor hearts were stored in cold UW solution .There were six pigs for donors and six for recipients in each group .Donor hearts were stored for 8 hours after isolation,and then were implanted into recipient pigs by orthotopic heart transplantation . Automatically rebeating of implanted heart and the frequency of defibrillation in both groups were recorded two hours after the aortic cross-clamp released,left and right ventricular function were measured as well .The changes of hemodynamics were observed 30 minutes after cardiopulmonary bypass.Results After being implanted into recipient pigs,6 donor hearts recovered automatic-beating 3 minutes after the aortic cross-clamp released in the beating-heart group;All of 6 donor hearts did not recovered automatic-beating in the cold UW storage group,and the frequency of defibrillation accounted for 12;Significant difference was found in the automatically rebeating rate of implanted heart between two groups (P<0.05).Two hours after the aortic cross-clamp released,left and right ventricular systolic pressure in the beating-heart group were significantly better than those in the cold UW storage group (all P<0.05);Thirty minutes after cardiopulmonary bypass, central venous pressure (CVP) and pulmonary capillary wedge pressure (PCWP) in the beating-heart group were significantly lower than those in the cold UW storage group (all P<0.05);Cardiac output(CO) and cardiac index(CI) in the beating-heart group were significantly higher than those in the cold UW storage group (P<0.05),and the dosages of dopamine and

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

    Science.gov (United States)

    Bonnemains, Laurent; Odille, Freddy; Meyer, Christophe; Hossu, Gabriella; Felblinger, Jacques; Vuissoz, Pierre-André

    2015-01-01

    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.

  14. 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.

  15. Ex Vivo Rehabilitation of Non-Heart-Beating Donor Lungs in a Preclinical Porcine Model: Delayed Perfusion Results in Superior Lung Function

    Science.gov (United States)

    Mulloy, Daniel P.; Stone, Matthew L.; Crosby, Ivan K.; LaPar, Damien J.; Sharma, Ashish K.; Webb, David V.; Lau, Christine L.; Laubach, Victor E.; Kron, Irving L.

    2012-01-01

    Objectives Ex vivo lung perfusion (EVLP) is a promising modality for the evaluation and treatment of marginal donor lungs. The optimal timing of EVLP initiation and potential for rehabilitation of donor lungs with extended warm-ischemic times is unknown. This study compares the efficacy of different treatment strategies for uncontrolled non-heart-beating donor lungs. Methods Mature swine underwent hypoxic arrest followed by 60 minutes of no-touch warm-ischemia. Lungs were harvested and flushed with 4°C Perfadex®. Three groups (n=5/group) were stratified according to preservation method: cold-static preservation (CSP: 4 hrs 4°C storage), immediate EVLP (I-EVLP: 4 hrs EVLP at 37°C), and delayed EVLP (D-EVLP: 4 hrs cold storage followed by 4 hrs EVLP). EVLP groups were perfused with Steen solution™ supplemented with heparin, methylprednisolone, cefazolin, and an adenosine 2A receptor agonist. Lungs then underwent allotransplantation and four hours of recipient reperfusion prior to allograft assessment for resultant ischemia-reperfusion injury. Results Donor blood oxygenation (PO2:FiO2) prior to euthanasia was not different between groups. Oxygenation after transplantation was significantly higher in the D-EVLP group compared to the I-EVLP or CSP groups. Mean airway pressure, pulmonary artery pressure, and expression of IL-8, IL-1β, and TNF-α were all significantly reduced in the D-EVLP group. Importantly, post-transplant oxygenation exceeded acceptable clinical levels only in D-EVLP lungs. Conclusions Uncontrolled non-heart-beating donor lungs with extended warm-ischemia can be reconditioned for successful transplantation. The combination of CSP and EVLP present in the D-EVLP group was necessary to obtain optimal post-transplant function. This finding, if confirmed clinically, will allow expanded use of non-heart-beating donor lungs. PMID:22944084

  16. A Multidisciplinary Approach to Unplanned Conversion from Off-Pump to On-Pump Beating Heart Coronary Artery Revascularization in Patients with Compromised Left Ventricular Function

    Directory of Open Access Journals (Sweden)

    Georgia Tsaousi

    2014-01-01

    Full Text Available Aim. To comparably assess the perioperative risk factors that differentiate off-pump coronary artery bypass (OPCAB grafting cases from those sustaining unplanned conversion to on-pump beating heart (ONCAB/BH approach, in patients with left ventricular ejection fraction (LVEF 2 days (P=0.007. Conclusions. Patients with LVEF < 40% undergoing ONCAB/BH are subjected to more preoperative comorbidities and implicated ICU stay than their OPCAB counterparts, which influences adversely short-term morbidity, while operative mortality remains unaffected.

  17. Binaural beat technology in humans: a pilot study to assess neuropsychologic, physiologic, and electroencephalographic effects.

    Science.gov (United States)

    Wahbeh, Helané; Calabrese, Carlo; Zwickey, Heather; Zajdel, Dan

    2007-03-01

    When two auditory stimuli of different frequency are presented to each ear, binaural beats are perceived by the listener. The binaural beat frequency is equal to the difference between the frequencies applied to each ear. Our primary objective was to assess whether steady-state entrainment of electroencephalographic activity to the binaural beat occurs when exposed to a specific binaural beat frequency as has been hypothesized. Our secondary objective was to gather preliminary data on neuropsychologic and physiologic effects of binaural beat technology. A randomized, blinded, placebo-controlled crossover experiment in 4 healthy adult subjects. Subjects were randomized to experimental auditory stimulus of 30 minutes of binaural beat at 7 Hz (carrier frequencies: 133 Hz L; 140 Hz R) with an overlay of pink noise resembling the sound of rain on one session and control stimuli of the same overlay without the binaural beat carrier frequencies on the other session. Data were collected during two separate sessions 1 week apart. Neuropsychologic and blood pressure data were collected before and after the intervention; electroencephalographic data were collected before, during, and after listening to either binaural beats or control. Neuropsychologic measures included State Trait Anxiety Inventory, Profile of Mood States, Rey Auditory Verbal List Test, Stroop Test, and Controlled Oral Word Association Test. Spectral and coherence analysis was performed on the electroencephalogram (EEG), and all measures were analyzed for changes between sessions with and without binaural beat stimuli. There were no significant differences between the experimental and control conditions in any of the EEG measures. There was an increase of the Profile of Mood States depression subscale in the experimental condition relative to the control condition (p = 0.02). There was also a significant decrease in immediate verbal memory recall (p = 0.03) in the experimental condition compared to control

  18. 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.

  19. 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

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

    Science.gov (United States)

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

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

  1. Interactions between heart rate variability and pulmonary gas exchange efficiency in humans.

    Science.gov (United States)

    Sin, Peter Y W; Webber, Matthew R; Galletly, Duncan C; Ainslie, Philip N; Brown, Stephen J; Willie, Chris K; Sasse, Alexander; Larsen, Peter D; Tzeng, Yu-Chieh

    2010-07-01

    The respiratory component of heart rate variability (respiratory sinus arrhythmia, RSA) has been associated with improved pulmonary gas exchange efficiency in humans via the apparent clustering and scattering of heart beats in time with the inspiratory and expiratory phases of alveolar ventilation, respectively. However, since human RSA causes only marginal redistribution of heart beats to inspiration, we tested the hypothesis that any association between RSA amplitude and pulmonary gas exchange efficiency may be indirect. In 11 patients with fixed-rate cardiac pacemakers and 10 healthy control subjects, we recorded R-R intervals, respiratory flow, end-tidal gas tension and the ventilatory equivalents for carbon dioxide and oxygen during 'fast' (0.25 Hz) and 'slow' paced breathing (0.10 Hz). Mean heart rate, mean arterial blood pressure, mean arterial pressure fluctuations, tidal volume, end-tidal CO(2), and were similar between pacemaker and control groups in both the fast and slow breathing conditions. Although pacemaker patients had no RSA and slow breathing was associated with a 2.5-fold RSA amplitude increase in control subjects (39 +/- 21 versus 97 +/- 45 ms, P exchange efficiency during variable-frequency paced breathing observed in prior human work is not contingent on RSA being present. Therefore, whether RSA serves an intrinsic physiological function in optimizing pulmonary gas exchange efficiency in humans requires further experimental validation.

  2. Data from acellular human heart matrix

    Directory of Open Access Journals (Sweden)

    Pedro L Sánchez

    2016-09-01

    Full Text Available Perfusion decellularization of cadaveric hearts removes cells and generates a cell-free extracellular matrix scaffold containing acellular vascular conduits, which are theoretically sufficient to perfuse and support tissue-engineered heart constructs. This article contains additional data of our experience decellularizing and testing structural integrity and composition of a large series of human hearts, “Acellular human heart matrix: a critical step toward whole heat grafts” (Sanchez et al., 2015 [1]. Here we provide the information about the heart decellularization technique, the valve competence evaluation of the decellularized scaffolds, the integrity evaluation of epicardial and myocardial coronary circulation, the pressure volume measurements, the primers used to assess cardiac muscle gene expression and, the characteristics of donors, donor hearts, scaffolds and perfusion decellularization process.

  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. 先心病心脏不停跳下心内直视手术(附555例报告)%The open-heart operation of congenital heart disea se with beating heart

    Institute of Scientific and Technical Information of China (English)

    陈林; 肖颖彬; 王学峰; 钟前进; 陈柏成; 陈进劲

    2001-01-01

    Objective:To introduce the experience of open-hear t operation of congenital heart disease in 555 cases on beating heart.Method:The operations were done under mild hypothermi c cardiopulmonary bypass .Cardiopulmonary bypass were initiated by cannulation of the aorta,and superior and inferior venae cavae,Only snailed the cava tapes without cross-clampping th e aorta.The perfusion rate was kept blood pressure at 60 mmHg and the body temp erature was around 32℃.The technique of repair the intracardiac malformation un der beating heart was just as same as under aorta cross-clamping.Result:There were eleven patients died(mortality rate 2.0%).Th e others were cured and followed-up for 1~13 months.The recovery were good.Conclusion:Our results shows that the technique i s a new good way for myocardial protection.It can reduce the complicationrate,si mp lify the operative procedure and shorten the mean cardiopulmonary bypass time.%目的:介绍浅低温体外循环心脏不停跳心内直视手 术治疗先天性心脏病心内畸形的应用体会。方法:555例先心病患者 采用该手术,常规建立体外循环,置左心房引流管,降温至32±1℃并维持,仅阻断上下腔 静脉,不阻断主动脉,维持灌注压在60 mmHg左右,心脏跳动下施行畸形矫正,方法同停跳 手术。结果:死亡11例(死亡率2.0%),其余均痊愈出院,随访1~13个月 ,恢复良好。结论:浅低温心脏不停跳心内直视手术,是一种有效的心肌保护方 法,能减少并发症的发生,缩短体外循环时间。

  5. Human fetal cardiac progenitors: The role of stem cells and progenitors in the fetal and adult heart.

    Science.gov (United States)

    Bulatovic, Ivana; Månsson-Broberg, Agneta; Sylvén, Christer; Grinnemo, Karl-Henrik

    2016-02-01

    The human fetal heart is formed early during embryogenesis as a result of cell migrations, differentiation, and formative blood flow. It begins to beat around gestation day 22. Progenitor cells are derived from mesoderm (endocardium and myocardium), proepicardium (epicardium and coronary vessels), and neural crest (heart valves, outflow tract septation, and parasympathetic innervation). A variety of molecular disturbances in the factors regulating the specification and differentiation of these cells can cause congenital heart disease. This review explores the contribution of different cardiac progenitors to the embryonic heart development; the pathways and transcription factors guiding their expansion, migration, and functional differentiation; and the endogenous regenerative capacity of the adult heart including the plasticity of cardiomyocytes. Unfolding these mechanisms will become the basis for understanding the dynamics of specific congenital heart disease as well as a means to develop therapy for fetal as well as postnatal cardiac defects and heart failure.

  6. Are there intracellular Ca2+ oscillations correlated with flagellar beating in human sperm? A three vs. two-dimensional analysis.

    Science.gov (United States)

    Corkidi, G; Montoya, F; Hernández-Herrera, P; Ríos-Herrera, W A; Müller, M F; Treviño, C L; Darszon, A

    2017-09-01

    Are there intracellular Ca2+ ([Ca2+]i) oscillations correlated with flagellar beating in human sperm? The results reveal statistically significant [Ca2+]i oscillations that are correlated with the human sperm flagellar beating frequency, when measured in three-dimensions (3D). Fast [Ca2+]i oscillations that are correlated to the beating flagellar frequency of cells swimming in a restricted volume have been detected in hamster sperm. To date, such findings have not been confirmed in any other mammalian sperm species. An important question that has remained regarding these observations is whether the fast [Ca2+]i oscillations are real or might they be due to remaining defocusing effects of the Z component arising from the 3D beating of the flagella. Healthy donors whose semen samples fulfill the WHO criteria between the age of 18-28 were selected. Cells from at least six different donors were utilized for analysis. Approximately the same number of experimental and control cells were analyzed. Motile cells were obtained by the swim-up technique and were loaded with Fluo-4 (Ca2+ sensitive dye) or with Calcein (Ca2+ insensitive dye). Ni2+ was used as a non-specific plasma membrane Ca2+ channel blocker. Fluorescence data and flagella position were acquired in 3D. Each cell was recorded for up to 5.6 s within a depth of 16 microns with a high speed camera (coupled to an image intensifier) acquiring at a rate of 3000 frames per second, while an oscillating objective vibrated at 90 Hz via a piezoelectric device. From these samples, eight experimental and nine control sperm cells were analyzed in both 2D and 3D. We have implemented a new system that allows [Ca2+]i measurements of the human sperm flagellum beating in 3D. These measurements reveal statistically significant [Ca2+]i oscillations that correlate with the flagellar beating frequency. These oscillations may arise from intracellular sources and/or Ca2+ transporters, as they were insensitive to external Ni2+, a non

  7. Testing of Dhoulath's method to speed up diagnose by separating up crying sound of a baby from normal heart beats – ‘An innovative time saving technique’

    Directory of Open Access Journals (Sweden)

    J. Dhoulath Beegum

    2016-09-01

    Full Text Available Medical world offers unforeseen ways and techniques in diagnosis of the rarest of rare diseases, of early detection, of prompt and speedy aid and treatment but, many are the hurdles to be overcome by doctors. The case undertaken precedes one such problem doctors confront during auscultation. The baby crying sound necessitates a pause – a pause to distract the baby and stop its cry without which diagnosis becomes impossible and erratic too, leading to time delay. An innovative time saving facility was pondered upon as the way out to gear up doctors to facilitate auscultation even when the baby continues to cry. Dhoulath's method is utilized for separation of the baby cry and normal heart beats. This time saving facility is highly effective during cardiac failures. The diagnosing time and the death rate is considered, while organizing the concept.

  8. Non-heart-beating donors of organs: are the distinctions between direct and indirect effects & between killing and letting die relevant and helpful?

    Science.gov (United States)

    Childress, J F

    1993-06-01

    This essay analyzes the principle of double effect and, to a lesser extent, the distinction between killing and letting die in the context of the Pittsburgh protocol for managing patients who may become non-heart-beating donors or sources of organs for transplantation. It notes several ambiguities and unresolved issues in the Pittsburgh protocol but concludes that neither the principle of double effect nor the distinction between killing and letting die (with the prohibition of the former and the allowance of the latter under some circumstances) erects insurmountable obstacles to the implementation of the protocol. Nevertheless, the requirement of the principle of double effect that the intended good effects outweigh the unintended side effects necessitates careful attention to the probable overall impact of the proposed policy on organ procurement, particularly because public mistrust plays such a significant role in limiting the number of organ donations.

  9. 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...

  10. Improved Cardiac Contractility of Human Recombinant Growth Hormone on the Congestive Heart Failure of Pig

    Institute of Scientific and Technical Information of China (English)

    Yang Ping; He Yu-quan; Zeng Hong; Ni Jin-song; Yun Qing-jun; Huang Xiao-ping; Li Shu-mei

    2005-01-01

    The enhanced cardiac contractility effect of human recombinant growth hormone (hr-GH) on the congestive heart failure (CHF) was studied on the pig. To build a pig model of congestive heart failure, a temporary artificial cardiac pacemaker was implanted in the pig's body and paced at 220 beats to 240 beats per minute for 1 week. After the model of congestive heart failure was successfully set up, the frequency of the pacemaker was changed to 150 beats to 180 beats per minute to maintain the CHF model stable. Pigs were divided into three groups: The hr-GH group in which 0.5 mg/kg per day of hr-GH was administrated intramuscularly for 15 days, the injection control group in which an equal amount of physiological saline was injected intramuscularly, and a normal control group. The left ventricular diastolic end pressure was (10.60±2.41 ) mmHg in the hr-GH group, but (19.00±3.81) mmHg in the saline control group (P<0.01); Cardiac output was (1.86±0.13) L/min in the hr-GH group, but (1.56 ±0.18) L/min in the saline control group (P<0.05); Peripheral min) -1 in the saline control group (P<0.05); ± dp/dtmax was (2900 ±316.23) and (2280 ±286.36) in the hr-HG group and the saline control group respectively (P<0.05). The results show that hr-GH enhances myocardial contractility of CHF, and the CHF model built by a temporary artificial cardiac pacemaker at a high rate of stimulation is reasonable and applicable.

  11. Clinical comparison of beating-heart and arrested-heart intracardiac procedure in pediatrics%婴幼儿心脏不停跳和停跳心内直视手术的临床对比

    Institute of Scientific and Technical Information of China (English)

    吴军; 何巍; 冯旭

    2011-01-01

    Objective;To compare the effects of mild hypothermia beating-heart cardiopulmonary bypass (CPB) with those of moderate hypothermia arrested-heat CPB in pediatric intracardiac procedure. Methods;56 patients whose age were under 3 years underwent open heart surgery. They were divided to group 1, 26 patients underwent arrested-heart operation, and group 2,30 patients underwent beating-heart operations. Duration of CPB and surgery,postoperative mechanical respiratory assistance duration and incidence of low cardiac output, ect,were compared between the tow groups. Results: Duration of CPB and operative duration in group 2 were shorter than those in group 1 ( P < 0.01), and postoperative mechanical respiratory assistance duration was shorter in group 2. The incidence of low cardiac output syndrome and serious cardiac arrhythmia in group 2 was lower than those in group 1, and postoperative residential duration was shorter in group 2. Conclusion:The mild hypothermia beating-heart CPB is a safe abd effective technique applied to pediatric cardiac surgery.%目的:比较浅低温心脏不停跳和中低温停跳技术,在婴幼儿心内直视手术的应用.方法:分析56例3岁以下心脏手术患者,将其分为停跳组(组Ⅰ)26例和不停跳组(组Ⅱ)30例.比较2组患者的体外循环(CPB)时间、手术时间、术后呼吸机辅助时间、术后低心排出量综合征(低心排)发生率等指标.结果:不停跳组患者的体外循环时间和手术时间均较停跳组短(P<0.01),并且术后呼吸机辅助时间、术后住院时间较停跳组短(P<0.05);不停跳组患者术后低心排发生率和严重心律失常发生率,均较停跳组低(P<0.05).结论:表明浅低温体外循环心脏不停跳,可作为一项安全、有效的技术应用于婴幼儿先天性心脏畸形的矫治.

  12. Total excitation of the isolated human heart

    NARCIS (Netherlands)

    Durrer, D.; Dam, R.Th. van; Freud, G.E.; Janse, M.J.; Meijler, F.L.; Arzbaecher, R.C.

    1970-01-01

    To obtain information conceming the time course and instantaneous distribution of the excitatory process of the normal human healt, studies were made on isolated human hearts from seven individuals who died from various cerebral conditions, but who had no history of cardiac disease. Measurements wer

  13. Heart rate variability, overnight urinary norepinephrine, and plasma cholesterol in apparently healthy human adults.

    Science.gov (United States)

    Thayer, Julian F; Fischer, Joachim E

    2013-01-20

    The aim of this study was to assess the relationship between autonomic nervous system activity as indexed by measures of heart rate variability and overnight urinary norepinephrine, and plasma cholesterol levels in a large sample of working adults. The study population comprised 611 apparently healthy employees of an airplane manufacturing plant in Southern Germany. Heart rate variability was calculated as beat-to-beat intervals over the course of one 24-hour weekday measured with an ambulatory ECG recorder. Overnight urine collection and blood samples were also obtained. We found an inverse association between indices of vagally-mediated heart rate variability and plasma levels of total cholesterol, low density lipoprotein (LDL), and the ratio of LDL to high density lipoprotein (HDL) that remained significant in multivariate models after controlling for relevant covariates including norepinephrine. Urinary norepinephrine was not significantly related to any measure of cholesterol in multivariate models. We report here for the first time, in a large sample of healthy human adults, evidence supporting the hypothesis of a clinically relevant inverse relationship between measures of plasma cholesterol and vagally-mediated heart rate variability after controlling for sympathetic nervous system activity. This suggests an important role for the vagal control of plasma cholesterol levels in cardiovascular disease. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

  14. Beat to beat variability in cardiovascular variables: noise or music?

    Science.gov (United States)

    Appel, M. L.; Berger, R. D.; Saul, J. P.; Smith, J. M.; Cohen, R. J.

    1989-01-01

    Cardiovascular variables such as heart rate, arterial blood pressure, stroke volume and the shape of electrocardiographic complexes all fluctuate on a beat to beat basis. These fluctuations have traditionally been ignored or, at best, treated as noise to be averaged out. The variability in cardiovascular signals reflects the homeodynamic interplay between perturbations to cardiovascular function and the dynamic response of the cardiovascular regulatory systems. Modern signal processing techniques provide a means of analyzing beat to beat fluctuations in cardiovascular signals, so as to permit a quantitative, noninvasive or minimally invasive method of assessing closed loop hemodynamic regulation and cardiac electrical stability. This method promises to provide a new approach to the clinical diagnosis and management of alterations in cardiovascular regulation and stability.

  15. Tissue microarray profiling in human heart failure.

    Science.gov (United States)

    Lal, Sean; Nguyen, Lisa; Tezone, Rhenan; Ponten, Fredrik; Odeberg, Jacob; Li, Amy; Dos Remedios, Cristobal

    2016-09-01

    Tissue MicroArrays (TMAs) are a versatile tool for high-throughput protein screening, allowing qualitative analysis of a large number of samples on a single slide. We have developed a customizable TMA system that uniquely utilizes cryopreserved human cardiac samples from both heart failure and donor patients to produce formalin-fixed paraffin-embedded sections. Confirmatory upstream or downstream molecular studies can then be performed on the same (biobanked) cryopreserved tissue. In a pilot study, we applied our TMAs to screen for the expression of four-and-a-half LIM-domain 2 (FHL2), a member of the four-and-a-half LIM family. This protein has been implicated in the pathogenesis of heart failure in a variety of animal models. While FHL2 is abundant in the heart, not much is known about its expression in human heart failure. For this purpose, we generated an affinity-purified rabbit polyclonal anti-human FHL2 antibody. Our TMAs allowed high-throughput profiling of FHL2 protein using qualitative and semiquantitative immunohistochemistry that proved complementary to Western blot analysis. We demonstrated a significant relative reduction in FHL2 protein expression across different forms of human heart failure. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  16. 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

  17. Electron-conformational transformations in nanoscopic RyR channels govern both the heart's contraction and beating

    CERN Document Server

    Moskvin, A S; Solovyova, O E; Markhasin, V S

    2011-01-01

    We show that a simple biophysically based electron-conformational model of RyR channel is able to explain and describe on equal footing the oscillatory regime of the heart's cell release unit both in sinoatrial node (pacemaker) cells under normal physiological conditions and in ventricular myocytes under Ca$^{2+}$ SR overload.

  18. Beneficial effect of antibiotics on ciliary beat frequency of human nasal epithelial cells exposed to bacterial toxins.

    Science.gov (United States)

    Mallants, Roel; Jorissen, Mark; Augustijns, Patrick

    2008-04-01

    In the present study, we explored whether the cilio-inhibitory effect induced by toxins derived from bacterial infections could be compensated for by a cilio-stimulatory effect of antibiotics. Human nasal epithelial cells (HNEC) expressing beating cilia were grown as monolayers. Ciliary beat frequency (CBF) was determined using an inverted microscope coupled with a high-speed digital camera. Clarithromycin and neomycin did not influence ciliary activity. Bacitracin, clindamycin, gramicidin and roxithromycin increased CBF significantly: by 50 +/- 12%, 54 +/- 16%, 31 +/- 16% and 31 +/- 18%, respectively. A 30 min exposure to Staphylococcus aureus enterotoxin B (SEB) and Pseudomonas aeruginosa lipopolysaccharide (PAL) decreased CBF significantly, by 37 +/- 16 and 28 +/- 12%, respectively. In contrast with exposure to the toxin alone, co-incubation of the nasal monolayer cells with PAL and bacitracin or clindamycin did not result in a decrease in CBF after 30 and 60 min. The effect of SEB could be compensated for by bacitracin but not by clindamycin. After a 12 h preincubation period with SEB, co-incubation with either bacitracin or clindamycin resulted in the complete recovery of CBF. This study suggests that topical antibiotic treatment of nasal infections could result in a dual positive effect, namely treatment of the bacterial infection and recovery of ciliary activity.

  19. Morphology and biomechanics of human heart

    Science.gov (United States)

    Chelnokova, Natalia O.; Golyadkina, Anastasiya A.; Kirillova, Irina V.; Polienko, Asel V.; Ivanov, Dmitry V.

    2016-03-01

    Object of study: A study of the biomechanical characteristics of the human heart ventricles was performed. 80 hearts were extracted during autopsy of 80 corpses of adults (40 women and 40 men) aged 31-70 years. The samples were investigated in compliance with the recommendations of the ethics committee. Methods: Tension and compression tests were performed with help of the uniaxial testing machine Instron 5944. Cardiometry was also performed. Results: In this work, techniques for human heart ventricle wall biomechanical properties estimation were developed. Regularities of age and gender variability in deformative and strength properties of the right and left ventricle walls were found. These properties were characterized by a smooth growth of myocardial tissue stiffness and resistivity at a relatively low strain against reduction in their strength and elasticity from 31-40 to 61-70 years. It was found that tissue of the left ventricle at 61-70 years had a lower stretchability and strength compared with tissues of the right ventricle and septum. These data expands understanding of the morphological organization of the heart ventricles, which is very important for the development of personalized medicine. Taking into account individual, age and gender differences of the heart ventricle tissue biomechanical characteristics allows to rationally choosing the type of patching materials during reconstructive operations on heart.

  20. Polyhexanide-containing solution reduces ciliary beat frequency of human nasal epithelial cells in vitro.

    Science.gov (United States)

    Birk, Richard; Aderhold, C; Stern-Sträter, J; Hörmann, K; Stuck, B A; Sommer, J U

    2015-02-01

    In ENT, polyhexanide-containing solutions are used to treat nasal infections caused by multiresistant bacteria like methicillin-resistant Staphylococcus aureus. Many forms of commercial nasal solutions containing polyhexanide exist, such as gels or solutions for topical use. Data regarding the influence of polyhexanide on ciliary beat frequency (CBF) are lacking to date. We tested the CBF of nasal ciliated epithelial cells under the influence of a commercially available polyhexanide-containing solution (Lavasept(®) Concentrate) in a therapeutic concentration (0.04, 0.02%). In addition, we tested the concentrations of 0.1 and 0.01%. Cells were visualized with a phase contrast microscope, and the CBF was measured with the SAVA system's region of interest method. Ringer's solution and macrogol served as negative controls. A therapeutic concentration of Lavasept significantly reduced CBF in a time- and concentration-dependent manner. After 1 min, the CBF was reduced from 8.90 ± 1.64 to 5.00 ± 3.72 Hz with a concentration of 0.04% (p value = 0.001). After 10 min, all cilia stopped beating. After 5 min, a 0.02% solution of Lavasept concentrate decreased CBF significantly from 8.64 ± 1.71 to 3.30 ± 3.27 Hz (p value polyhexanide-containing solution Lavasept in some therapeutic concentrations. Due to our findings in this study, Lavasept should be used on ciliated mucosa only with caution and in a concentration of 0.02%.

  1. Cryodissection of vessels of the human heart

    Directory of Open Access Journals (Sweden)

    Okolokulak E.S.

    2015-03-01

    Full Text Available Background. One of the most actual problems of applied morphology is the problem of demonstrativeness. In the educational process it is important to demonstrate the organs taken from the human body with all features of their structure preserved. The basic method of normal anatomy is a dissection of cadaveric material. It gives anatomical preparations demonstrating the structure of the human body. But classical dissection has certain difficulties: the complexity of layer-by-layer tissue separation and extraction of important anatomical structures. Currently for the manufacture of anatomical preparations a number of other methods are used: method of corrosion and polymeric embalming. However these techniques are time consuming, expensive, and also can cause damage to the structures of the heart during their extraction out of adipose tissue. Objective. To create a new method for the dissection of the human heart, allowing to reduce the time and to improve the quality of the preparations. Methods. We have prepared two solutions with different freezing temperature. Tissue which needed to be preserved (myocardium was impregnated with solution №1. Tissue that need to be deleted (adipose tissue, impregnated with solution №2. After freezing the heart myocardium frizzes, but unfrozen adipose tissue could be easily separated. We examined 30 human hearts: 15 preparations by the classical dissection, 15 preparations with the help of cryodissection. Results. Preparation of hearts by the classical method took about 180 minutes, with the help of cryodissection – 30 minutes. Visualization of the coronary arteries and their branches after our method is better, myocardium is smooth, also preserve the natural color of the drug. Additionally, there is no contact of the researcher with harmful conservatives (for example formaldehyde. Conclusion. We have developed a method for dissection of cadaveric material, which improves the quality of anatomical

  2. Cardiac tamponade and para-aortic hematoma post elective surgical myocardial revascularization on a beating heart - a possible complication of the Lima-stitch and sequential venous anastomosis.

    Science.gov (United States)

    Marcinkiewicz, Anna; Jaszewski, Ryszard; Piestrzeniewicz, Katarzyna; Zwoliński, Radosław

    2014-06-04

    Off-pump coronary artery bypass (OPCAB) surgery can be associated with some intrinsic, but relatively rare complications. A pericardial effusion is a common finding after cardiac surgeries, but the prevalence of a cardiac tamponade does not exceed 2% and is less frequent after myocardial revascularization.Authors believe that in our patient an injury of a nutritional pericardial or descending aorta vessel caused by the Lima stitch resulted in oozing bleeding, which gradually leaded to cardiac tamponade. The bleeding increased after introduction of double antiplatelet therapy and caused life-threatening hemodynamic destabilization. According to our knowledge it is the first report of such a complication after OPCAB. We present a case of a 61-year old man, who underwent elective surgical myocardial revascularization on a beating heart. On the 11th postoperative day the patient was readmitted emergently to the intensive care unit for severe chest pain, dyspnoea and hypotension. Coronary angiographic control showed a patency of the bypass grafts and significant narrowing of circumflex artery, treated with angioplasty and stenting. The symptoms and hemodynamic instability exacerbated. A suspicion of dissection of the ascending aorta and para-aortic hematoma was stated on 16-slice cardiac computed tomography. The patient was referred to the Cardiovascular Surgery Clinic. Transthoracic echocardiography revealed cardiac tamponade. On transesophageal echocardiography there were no signs of the ascending aorta dissection, but a possible lesion of the descending aorta with para-aortic hematoma was visualized. Emergent rethoracotomy and cardiac tamponade decompression were performed. 12 days after intervention the control 64-slice computed tomography showed no lesions of the ascending or descending aorta. On one-year follow-up patient is in a good condition, the left ventricular function is preserved and there is no pathology in thoracic aorta on echocardiography. Mechanical

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

    Directory of Open Access Journals (Sweden)

    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

  4. 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, ...

  5. Scaling analysis of heart beat fluctuations data and its relationship with cyclic alternating pattern data during sleep

    Science.gov (United States)

    de León-Lomelí, R.; Murguía, J. S.; Chouvarda, I.; Méndez, M. O.; González-Galván, E.; Alba, A.

    2016-01-01

    During sleep there exists a nonlinear dynamic phenomenon, which is called cyclic alternating pattern. This phenomenon is generated in the brain and is composed of a series of events of short duration known as A-phases. It has been shown that A-phases can be found in other physiological systems such as the cardiovascular. However, there is no evidence that shows the temporal influence of the A-phases with the cardiovascular system. For this purpose, we consider the scaling method known as detrended fluctuation analysis (DFA). The analysis was carried out in well sleepers and insomnia people, and the numerical results show an increment in the scaling parameter for the insomnia subjects compared with the normal ones. In addition, the results of the heart dynamics suggests a persistent behavior toward the 1/f-noise.

  6. The beat of social cognition: exploring the role of Heart Rate Variability as marker of mentalizing abilities.

    Science.gov (United States)

    Okruszek, Łukasz; Dolan, Kirsty; Lawrence, Megan; Cella, Matteo

    2016-10-04

    There is a long standing debate on the influence of physiological signals on social behavior. Recent studies suggested that heart rate variability (HRV) may be a marker of social cognitive processes. However, this evidence is preliminary and limited to laboratory studies. In this study 25 participants were assessed with a social cognition battery and asked to wear a wearable device measuring HRV for 6 consecutive days. The results showed that reduced HRV correlated with higher hostility attribution bias. However, no relationship was found between HRV and other social cognitive measures including facial emotion recognition, theory of mind or emotional intelligence. These results suggest that HRV may be linked to specific social cognitive processes requiring online emotional processing, in particular those related to social threat. These findings are discussed in the context of the neurovisceral integration model.

  7. Effects of whole body heating on dynamic baroreflex regulation of heart rate in humans

    Science.gov (United States)

    Crandall, C. G.; Zhang, R.; Levine, B. D.

    2000-01-01

    The purpose of this project was to identify whether dynamic baroreflex regulation of heart rate (HR) is altered during whole body heating. In 14 subjects, dynamic baroreflex regulation of HR was assessed using transfer function analysis. In normothermic and heat-stressed conditions, each subject breathed at a fixed rate (0. 25 Hz) while beat-by-beat HR and systolic blood pressure (SBP) were obtained. Whole body heating significantly increased sublingual temperature, HR, and forearm skin blood flow. Spectral analysis of HR and SBP revealed that the heat stress significantly reduced HR and SBP variability within the high-frequency range (0.2-0.3 Hz), reduced SBP variability within the low-frequency range (0.03-0.15 Hz), and increased the ratio of low- to high-frequency HR variability (all P regulation of HR within the high-frequency range (from 1.04 +/- 0.06 to 0.54 +/- 0.6 beats. min(-1). mmHg(-1); P body heating reduced high-frequency dynamic baroreflex regulation of HR associated with spontaneous changes in blood pressure. Reduced vagal baroreflex regulation of HR may contribute to reduced orthostatic tolerance known to occur in humans during heat stress.

  8. 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.

  9. Non-Heart-Beating Donor Kidney Transplantation Survival Is Similar to Donation After Brain Death: Comparative Study With Controls in a Regional Program.

    Science.gov (United States)

    Gentil, M A; Castro de la Nuez, P; Gonzalez-Corvillo, C; de Gracia, M C; Cabello, M; Mazuecos, M A; Rodriguez-Benot, A; Ballesteros, L; Osuna, A; Alonso, M

    2016-11-01

    Non-heart-beating donors (NHBD) are an increasing source of organs for kidney transplantation (KT) compared with donation after brain death (DBD), but the results in each regional transplantation program require local analysis. We compared 164 KT from NHBD (83 Maastrich type II A-B [T2] and 81 type III [T3]) with 328 DBD controls. NHBD kidneys were implanted with less cold ischemia, mean time on renal replacement therapy for NHBD recipients before transplantation was less too, and a higher proportion of thymoglobulin was also used. Besides NHBD-T2 more frequently showing the A group and patients being younger (48.9 ± 11 vs DBD 55.2 ± 15 years old; P DBD 4.3 and 26.9% (P DBD; P DBD, respectively (not significant [NS]). Graft survival rates censored by death were 91% and 89% (1st and 3rd years, respectively) versus 95% and 94% for DBD, respectively (NS). We did not find significant differences about survival between NHBD-T2 and T3. In the multivariable survival study (Cox, covariables with statistical significance demonstrated previously in our region), NHBD is not a prognosis factor for recipient or graft survival. Regarding current criteria for choosing donors and the graft allocation applied in Andalusia, short-term survival for NHBD transplantation is similar to DBD. Renal function in the short term is slightly worse, which is why it is important to monitor results over a long term, especially those from NHBD-T2.

  10. Dynamical changing patterns of histological structure and ultrastructure of liver graft undergoing warm ischemia injury from non-heart-beating donor in rats

    Institute of Scientific and Technical Information of China (English)

    Yi Ma; Guo-Dong Wang; Lin-Wei Wu; Rui-De Hu

    2006-01-01

    AIM: To investigate the histological and ultra-structural characteristics of liver graft during different of warm ischemia time (WIT) in rats and to predict the maximum limitation of liver graft to warm ischemia. METHODS: The rats were randomized into 7 groups undergoing warm ischemia injury for 0, 10, 15, 20, 30,45 and 60 min, respectively. All specimens having undergone warm ischemia injury were investigated dynamically by light and electron microscopy, and histochemistry staining. After orthotopic liver transplantation (OLT), the recovery of morphology of liver grafts after 6, 24 and 48 h was observed. RESULTS: The donor liver from non-heart-beating donors (NHBD) underwent ischemia injury both in the warm ischemia period and in the reperfusion period. Morphological changes were positively related to warm ischemia injury in a time-dependent manner during the reperfusion period. The results demonstrated that different degrees of histocyte degeneration were observed when WIT was within 30 min, and became more severe with the prolongation of WIT, no obvious hepatocyte necrosis was noted in any specimen. In the group undergolng warm ischemia injury for 45 min, small focal necrosis occurred in the central area of hepatic lobule first. In the group undergoing warm ischemia injury for 60 min, patchy or diffused necrosis was observed and the area was gradually extended, while hepatic sinusoid endothe lial cells were obviously swollen. Hepatic sinusoid was obstructed and microcirculation was in disorder. CONCLUSION: The rat liver graft undergoing warm ischemia injury is in the reversible stage when the WIT is within 30 min. The 45 min WIT may be a critical point of rat liver graft to endure warm ischemia injury. When the WIT is over 60 min, the damage is irreversible.

  11. 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 bradycardia...

  12. Parallel computing simulation of electrical excitation and conduction in the 3D human heart.

    Science.gov (United States)

    Di Yu; Dongping Du; Hui Yang; Yicheng Tu

    2014-01-01

    A correctly beating heart is important to ensure adequate circulation of blood throughout the body. Normal heart rhythm is produced by the orchestrated conduction of electrical signals throughout the heart. Cardiac electrical activity is the resulted function of a series of complex biochemical-mechanical reactions, which involves transportation and bio-distribution of ionic flows through a variety of biological ion channels. Cardiac arrhythmias are caused by the direct alteration of ion channel activity that results in changes in the AP waveform. In this work, we developed a whole-heart simulation model with the use of massive parallel computing with GPGPU and OpenGL. The simulation algorithm was implemented under several different versions for the purpose of comparisons, including one conventional CPU version and two GPU versions based on Nvidia CUDA platform. OpenGL was utilized for the visualization / interaction platform because it is open source, light weight and universally supported by various operating systems. The experimental results show that the GPU-based simulation outperforms the conventional CPU-based approach and significantly improves the speed of simulation. By adopting modern computer architecture, this present investigation enables real-time simulation and visualization of electrical excitation and conduction in the large and complicated 3D geometry of a real-world human heart.

  13. Stretchable, multiplexed pH sensors with demonstrations on rabbit and human hearts undergoing ischemia.

    Science.gov (United States)

    Chung, Hyun-Joong; Sulkin, Matthew S; Kim, Jong-Seon; Goudeseune, Camille; Chao, Hsin-Yun; Song, Joseph W; Yang, Sang Yoon; Hsu, Yung-Yu; Ghaffari, Roozbeh; Efimov, Igor R; Rogers, John A

    2014-01-01

    Stable pH is an established biomarker of health, relevant to all tissues of the body, including the heart. Clinical monitoring of pH in a practical manner, with high spatiotemporal resolution, is particularly difficult in organs such as the heart due to its soft mechanics, curvilinear geometry, heterogeneous surfaces, and continuous, complex rhythmic motion. The results presented here illustrate that advanced strategies in materials assembly and electrochemical growth can yield interconnected arrays of miniaturized IrOx pH sensors encapsulated in thin, low-modulus elastomers to yield conformal monitoring systems capable of noninvasive measurements on the surface of the beating heart. A thirty channel custom data acquisition system enables spatiotemporal pH mapping with a single potentiostat. In vitro testing reveals super-Nernstian sensitivity with excellent uniformity (69.9 ± 2.2 mV/pH), linear response to temperature (-1.6 mV °C(-1) ), and minimal influence of extracellular ions (sensor arrays on balloon catheters and on skin-like stretchable membranes. Real-time measurement of pH on the surfaces of explanted rabbit hearts and a donated human heart during protocols of ischemia-reperfusion illustrate some of the capabilities. Envisioned applications range from devices for biological research, to surgical tools and long-term implants.

  14. Three-Dimensional Human Cardiac Tissue Engineered by Centrifugation of Stacked Cell Sheets and Cross-Sectional Observation of Its Synchronous Beatings by Optical Coherence Tomography.

    Science.gov (United States)

    Haraguchi, Yuji; Hasegawa, Akiyuki; Matsuura, Katsuhisa; Kobayashi, Mari; Iwana, Shin-Ichi; Kabetani, Yasuhiro; Shimizu, Tatsuya

    2017-01-01

    Three-dimensional (3D) tissues are engineered by stacking cell sheets, and these tissues have been applied in clinical regenerative therapies. The optimal fabrication technique of 3D human tissues and the real-time observation system for these tissues are important in tissue engineering, regenerative medicine, cardiac physiology, and the safety testing of candidate chemicals. In this study, for aiming the clinical application, 3D human cardiac tissues were rapidly fabricated by human induced pluripotent stem (iPS) cell-derived cardiac cell sheets with centrifugation, and the structures and beatings in the cardiac tissues were observed cross-sectionally and noninvasively by two optical coherence tomography (OCT) systems. The fabrication time was reduced to approximately one-quarter by centrifugation. The cross-sectional observation showed that multilayered cardiac cell sheets adhered tightly just after centrifugation. Additionally, the cross-sectional transmissions of beatings within multilayered human cardiac tissues were clearly detected by OCT. The observation showed the synchronous beatings of the thicker 3D human cardiac tissues, which were fabricated rapidly by cell sheet technology and centrifugation. The rapid tissue-fabrication technique and OCT technology will show a powerful potential in cardiac tissue engineering, regenerative medicine, and drug discovery research.

  15. Heart Disease: A Price Humans Pay for Fertility?

    Science.gov (United States)

    ... page: https://medlineplus.gov/news/fullstory_166826.html Heart Disease: A Price Humans Pay for Fertility? Study finds ... 22, 2017 (HealthDay News) -- Certain genes linked to heart disease may also improve your chances of having children, ...

  16. Management of cardiopulmonary bypass for open heart surgery with beating heart%心脏跳动下心内直视手术的体外循环管理

    Institute of Scientific and Technical Information of China (English)

    杨宗英; 马瑞彦; 肖颖彬; 刘梅; 彭莉; 胡卫

    2011-01-01

    Objective To discuss the management melhods of cardiopulmonary bypass ( CPB) for palienls underwent open heart surgery with healing heart. Methods The CPB management melhods for 2 290 palienls underwenl open heart surgery with healing heart were summed-up. The left heart venling was established during the surgery and inlegraled sequelial de-airing procedure was conducted al the end of the surgery. The temperalure of nasopharynx was mainlained between 30 ~32 ℃, hemalocril was kept between 20% ~30% and the flow was controlled belween 2.4 ~3. 2 L·m-1· min-2 . Α-stat blood gas strategies were applied, meanwhile conventional ullrafilltration or modified ul-trafillralion was performed according to the condition. Results CPB went sucessful in all cases, the CPB time was 22 ~ 179 minules. Ventricular fibrillation was occurred in 256 cases and 181 cases experienced automatic recovery to healing. There were 22 cases died including 15 cases of complex congenital heart disease and 7 cases of severe valvular heart disease. No complication correlated wilh perfusion was oberved. Conclusion Open heart sugery wilh beating heart under mild hypothermia by cardiopulmonary bypass is safe and feasible, meanwhile it is easy for management and il can effectively prevenl ischemia reperfusion injury.%目的 探讨心脏跳动下心内直视手术中体外循环的管理方法.方法 总结分析2 290例心脏跳动下行心内直视手术的体外循环管理方法.术中均常规建立左心引流,术毕采用综合序贯排气技术.转流中鼻咽温维持在30~32 ℃,红细胞压积维持在20%~30%,流量控制在2.4~3.2 L·m-1·min-2,采用α稳态血气管理方法,术中酌情行常规超滤或改良超滤.结果 全组体外循环均顺利停机,转流时间22~179 min.术中室颤256例,其中181例自动复跳.全组死亡22例,其中复杂先天性心脏病15例,重症瓣膜病7例.全组无体外循环气栓并发症.结论 浅低温体外循环方法在心脏跳动

  17. Discrete Scale Invariance in the Cascade Heart Rate Variability Of Healthy Humans

    CERN Document Server

    Lin, D C

    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.

  18. Functional improvement and maturation of rat and human engineered heart tissue by chronic electrical stimulation.

    Science.gov (United States)

    Hirt, Marc N; Boeddinghaus, Jasper; Mitchell, Alice; Schaaf, Sebastian; Börnchen, Christian; Müller, Christian; Schulz, Herbert; Hubner, Norbert; Stenzig, Justus; Stoehr, Andrea; Neuber, Christiane; Eder, Alexandra; Luther, Pradeep K; Hansen, Arne; Eschenhagen, Thomas

    2014-09-01

    Spontaneously beating engineered heart tissue (EHT) represents an advanced in vitro model for drug testing and disease modeling, but cardiomyocytes in EHTs are less mature and generate lower forces than in the adult heart. We devised a novel pacing system integrated in a setup for videooptical recording of EHT contractile function over time and investigated whether sustained electrical field stimulation improved EHT properties. EHTs were generated from neonatal rat heart cells (rEHT, n=96) or human induced pluripotent stem cell (hiPSC)-derived cardiomyocytes (hEHT, n=19). Pacing with biphasic pulses was initiated on day 4 of culture. REHT continuously paced for 16-18 days at 0.5Hz developed 2.2× higher forces than nonstimulated rEHT. This was reflected by higher cardiomyocyte density in the center of EHTs, increased connexin-43 abundance as investigated by two-photon microscopy and remarkably improved sarcomere ultrastructure including regular M-bands. Further signs of tissue maturation include a rightward shift (to more physiological values) of the Ca(2+)-response curve, increased force response to isoprenaline and decreased spontaneous beating activity. Human EHTs stimulated at 2Hz in the first week and 1.5Hz thereafter developed 1.5× higher forces than nonstimulated hEHT on day 14, an ameliorated muscular network of longitudinally oriented cardiomyocytes and a higher cytoplasm-to-nucleus ratio. Taken together, continuous pacing improved structural and functional properties of rEHTs and hEHTs to an unprecedented level. Electrical stimulation appears to be an important step toward the generation of fully mature EHT.

  19. Sodium MRI in human heart: a review.

    Science.gov (United States)

    Bottomley, Paul A

    2016-02-01

    This paper offers a critical review of the properties, methods and potential clinical application of sodium ((23)Na) MRI in human heart. Because the tissue sodium concentration (TSC) in heart is about ~40 µmol/g wet weight, and the (23)Na gyromagnetic ratio and sensitivity are respectively about one-quarter and one-11th of that of hydrogen ((1)H), the signal-to-noise ratio of (23)Na MRI in the heart is about one-6000th of that of conventional cardiac (1)H MRI. In addition, as a quadrupolar nucleus, (23)Na exhibits ultra-short and multi-component relaxation behavior (T1 ~ 30 ms; T2 ~ 0.5-4 ms and 12-20 ms), which requires fast, specialized, ultra-short echo-time MRI sequences, especially for quantifying TSC. Cardiac (23)Na MRI studies from 1.5 to 7 T measure a volume-weighted sum of intra- and extra-cellular components present at cytosolic concentrations of 10-15 mM and 135-150 mM in healthy tissue, respectively, at a spatial resolution of about 0.1-1 ml in 10 min or so. Currently, intra- and extra-cellular sodium cannot be unambiguously resolved without the use of potentially toxic shift reagents. Nevertheless, increases in TSC attributable to an influx of intra-cellular sodium and/or increased extra-cellular volume have been demonstrated in human myocardial infarction consistent with prior animal studies, and arguably might also be seen in future studies of ischemia and cardiomyopathies--especially those involving defects in sodium transport. While technical implementation remains a hurdle, a central question for clinical use is whether cardiac (23)Na MRI can deliver useful information unobtainable by other more convenient methods, including (1)H MRI.

  20. Protective effects of L-arginine against ischemia-reper fusion injur y in non-heart beating rat liver graft

    Institute of Scientific and Technical Information of China (English)

    Jin Gong; Xue-Jun Lao; Shui-Jun Zhang; Shi Chen

    2008-01-01

    BACKGROUND: Although the use of non-heart beating donors (NHBDs) could bridge the widening gap between organ demand and supply, its application to liver transplantation is limited due to the high incidence of primary graft loss. Prevention of liver injury in NHBDs will beneift the results of transplantation. This study was conducted to evaluate the protective effects of L-arginine on liver grafts from NHBDs. METHODS: One hundred and four Wistar rats were randomly divided into 7 groups: normal control (n=8), controls 1, 2 and 3 (C1, C2, C3, n=16), and experimental 1, 2 and 3 (E1, E2, E3, n=16). For groups C1 and E1, C2 and E2, and C3 and E3, the warm ischemia time was 0, 30, and 45 minutes, respectively. Liver grafts were lfushed with and preserved in 4 ℃ Euro-collins solution containing 1 mmol/L L-arginine for 1 hour in each experimental group. Recipients of each experimental group were injected with L-arginine (10 mg/kg body weight) by tail vein 10 minutes before portal vein reperfusion. Donors and recipients of each experimental control group were treated with normal saline. Then transplantation was performed. At 1, 3, and 24 hours after portal vein reperfusion, blood samples were obtained to determine the levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), nitric oxide (NO) and plasma endothelin (ET). At 3 hours after portal vein reperfusion, grafts samples were ifxed in 2.5%glutaraldehyde for electron microscopic observation. RESULTS: At 1 hour after portal vein reperfusion, the levels of NO in groups E1, E2, E3 and C1, C2, C3 were lower, while the levels of plasma ET, serum ALT and AST were higher than those in the normal control group (P CONCLUSIONS: The imbalance between NO and ET plays an important role in the development of ischemia-reperfusion injury of liver grafts from NHBDs. L-arginine can attenuate injury in liver grafts from NHBDs by improving the balance between NO and ET.

  1. Model human heart or brain signals

    CERN Document Server

    Tuncay, Caglar

    2008-01-01

    A new model is suggested and used to mimic various spatial or temporal designs in biological or non biological formations where the focus is on the normal or irregular electrical signals coming from human heart (ECG) or brain (EEG). The electrical activities in several muscles (EMG) or neurons or other organs of human or various animals, such as lobster pyloric neuron, guinea pig inferior olivary neuron, sepia giant axon and mouse neocortical pyramidal neuron and some spatial formations are also considered (in Appendix). In the biological applications, several elements (cells or tissues) in an organ are taken as various entries in a representative lattice (mesh) where the entries are connected to each other in terms of some molecular diffusions or electrical potential differences. The biological elements evolve in time (with the given tissue or organ) in terms of the mentioned connections (interactions) besides some individual feedings. The anatomical diversity of the species (or organs) is handled in terms o...

  2. Global transcriptional profiles of beating clusters derived from human induced pluripotent stem cells and embryonic stem cells are highly similar

    Directory of Open Access Journals (Sweden)

    Gupta Manoj K

    2010-09-01

    Full Text Available Abstract Background Functional and molecular integrity of cardiomyocytes (CMs derived from induced pluripotent stem (iPS cells is essential for their use in tissue repair, disease modelling and drug screening. In this study we compared global transcriptomes of beating clusters (BCs microdissected from differentiating human iPS cells and embryonic stem (ES cells. Results Hierarchical clustering and principal component analysis revealed that iPS-BCs and ES-BCs cluster together, are similarly enriched for cardiospecific genes and differ in expression of only 1.9% of present transcripts. Similarly, sarcomeric organization, electrophysiological properties and calcium handling of iPS-CMs were indistinguishable from those of ES-CMs. Gene ontology analysis revealed that among 204 genes that were upregulated in iPS-BCs vs ES-BCs the processes related to extracellular matrix, cell adhesion and tissue development were overrepresented. Interestingly, 47 of 106 genes that were upregulated in undifferentiated iPS vs ES cells remained enriched in iPS-BCs vs ES-BCs. Most of these genes were found to be highly expressed in fibroblasts used for reprogramming and 34% overlapped with the recently reported iPS cell-enriched genes. Conclusions These data suggest that iPS-BCs are transcriptionally highly similar to ES-BCs. However, iPS-BCs appear to share some somatic cell signature with undifferentiated iPS cells. Thus, iPS-BCs may not be perfectly identical to ES-BCs. These minor differences in the expression profiles may occur due to differential cellular composition of iPS-BCs and ES-BCs, due to retention of some genetic profile of somatic cells in differentiated iPS cell-derivatives, or both.

  3. Human engineered heart tissue as a versatile tool in basic research and preclinical toxicology.

    Directory of Open Access Journals (Sweden)

    Sebastian Schaaf

    Full Text Available Human embryonic stem cell (hESC progenies hold great promise as surrogates for human primary cells, particularly if the latter are not available as in the case of cardiomyocytes. However, high content experimental platforms are lacking that allow the function of hESC-derived cardiomyocytes to be studied under relatively physiological and standardized conditions. Here we describe a simple and robust protocol for the generation of fibrin-based human engineered heart tissue (hEHT in a 24-well format using an unselected population of differentiated human embryonic stem cells containing 30-40% α-actinin-positive cardiac myocytes. Human EHTs started to show coherent contractions 5-10 days after casting, reached regular (mean 0.5 Hz and strong (mean 100 µN contractions for up to 8 weeks. They displayed a dense network of longitudinally oriented, interconnected and cross-striated cardiomyocytes. Spontaneous hEHT contractions were analyzed by automated video-optical recording and showed chronotropic responses to calcium and the β-adrenergic agonist isoprenaline. The proarrhythmic compounds E-4031, quinidine, procainamide, cisapride, and sertindole exerted robust, concentration-dependent and reversible decreases in relaxation velocity and irregular beating at concentrations that recapitulate findings in hERG channel assays. In conclusion this study establishes hEHT as a simple in vitro model for heart research.

  4. Pathogenic Mineralization of Calcium Phosphate on Human Heart Valves

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    When calcium phosphate forms in soft tissues such as blood vessels and heart valves, it causes disease. The abnormal formation of calcium phosphate is called pathogenic mineralization or pathogenic calcification. Cases of rheumatic heart disease (RHD) always occur with fibrotic and calcified tissue of heart valve. In this article, samples taken from calcified human heart valves were studied. The characterization was performed by scanning electronic micrascope, X-ray Diffraction and transmission electron microscopy with selective diffraction patterns. It is found for the first time that calcium phosphate grains existing in the calcified human heart valves contain octacalcium phosphate (OCP).

  5. Rhythminotropic Reactions of Human Myocardium in Ischemic and Rheumatic Heart Diseases against the Background of Amiodarone

    Directory of Open Access Journals (Sweden)

    Boris N. Kozlov, PhD, ScD

    2012-03-01

    Full Text Available In human heart failure, Ca2+ homeostasis gets disturbed due to a decrease in the function of the sarcoplasmic reticulum (SR. We studied the differences in the SR function in patients with rheumatic and coronary heart disease, against the background of amiodarone. Cardiac preparations from the atrium of 21 patients with coronary artery disease (CAD and 14 patients with rheumatic heart disease (RHD were used in this study. Myocardial strips perfused with oxygenated Krebs-Henzelait solution without and with amiodarone (1 mM/l at 37°C. The steady state stimulation rate of the muscle strips was 0.5 Hz. The single extraordinary impulse was given as 0.2-1.5 sec after the steady state beat. Then, the first beat after a 4- to 60-sec rest period was evaluated. The extrasystoles of the myocardium in both groups, after long intervals, were decreased after amiodarone treatment. The amplitude of post extrasystoles of amiodarone-treated myocardium showed differences only after long intervals in both groups. Two types of inotropic responses of a failing myocardium after rest periods were observed. Type I post-rest contractions maintained the steady state amplitude after all rests. However, type II was characterized by a reduction in the amplitude of the contractions. Amiodarone treatment of the myocardium showing type I reactions led to an increase in the potentiation after rests, but showed no effect on the reaction of the muscle with the type II response. The results suggested that SR dysfunction was different in CAD and RHD. The realization of the therapeutic effect of amiodarone was found to be dependent on the functional activity of the SR.

  6. ILK induces cardiomyogenesis in the human heart.

    Directory of Open Access Journals (Sweden)

    Alexandra Traister

    Full Text Available BACKGROUND: Integrin-linked kinase (ILK is a widely conserved serine/threonine kinase that regulates diverse signal transduction pathways implicated in cardiac hypertrophy and contractility. In this study we explored whether experimental overexpression of ILK would up-regulate morphogenesis in the human fetal heart. METHODOLOGY/PRINCIPAL FINDINGS: Primary cultures of human fetal myocardial cells (19-22 weeks gestation yielded scattered aggregates of cardioblasts positive for the early cardiac lineage marker nk × 2.5 and containing nascent sarcomeres. Cardiac cells in colonies uniformly expressed the gap junction protein connexin 43 (C × 43 and displayed a spectrum of differentiation with only a subset of cells exhibiting the late cardiomyogenic marker troponin T (cTnT and evidence of electrical excitability. Adenovirus-mediated overexpression of ILK potently increased the number of new aggregates of primitive cardioblasts (p<0.001. The number of cardioblast colonies was significantly decreased (p<0.05 when ILK expression was knocked down with ILK targeted siRNA. Interestingly, overexpression of the activation resistant ILK mutant (ILK(R211A resulted in much greater increase in the number of new cell aggregates as compared to overexpression of wild-type ILK (ILK(WT. The cardiomyogenic effects of ILK(R211A and ILK(WT were accompanied by concurrent activation of β-catenin (p<0.001 and increase expression of progenitor cell marker islet-1, which was also observed in lysates of transgenic mice with cardiac-specific over-expression of ILK(R211A and ILK(WT. Finally, endogenous ILK expression was shown to increase in concert with those of cardiomyogenic markers during directed cardiomyogenic differentiation in human embryonic stem cells (hESCs. CONCLUSIONS/SIGNIFICANCE: In the human fetal heart ILK activation is instructive to the specification of mesodermal precursor cells towards a cardiomyogenic lineage. Induction of cardiomyogenesis by ILK

  7. How Is Heart Failure Diagnosed?

    Science.gov (United States)

    ... your heart pumps blood when it beats. Doppler Ultrasound A Doppler ultrasound uses sound waves to measure ... when your heart is working hard and beating fast. During stress testing , you exercise to make your ...

  8. 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

  9. 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.

  10. 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

  11. [Heart rate measurement algorithm based on artificial intelligence].

    Science.gov (United States)

    Chengxian, Cai; Wei, Wang

    2010-01-01

    Based on the heart rate measurement method using time-lapse image of human cheek, this paper proposes a novel measurement algorithm based on Artificial Intelligence. The algorithm combining with fuzzy logic theory acquires the heart beat point by using the defined fuzzy membership function of each sampled point. As a result, it calculates the heart rate by counting the heart beat points in a certain time period. Experiment shows said algorithm satisfies in operability, accuracy and robustness, which leads to constant practical value.

  12. Comparative study of myocardial protection in cardiac arrest and beating heart surgery%心脏停跳与不停跳手术心肌保护的临床对比研究

    Institute of Scientific and Technical Information of China (English)

    王建堂; 马增山; 董铭峰; 马胜军

    2013-01-01

    目的 评价心脏停跳与不停跳手术对先天性心脏病患者的心肌保护效果.方法 房间隔缺损(ASD)、室间隔缺损(VSD)、肺动脉瓣狭窄(PS)患者共116例,随机分为实验组(不停跳组)和对照组(停跳组).实验组在体外循环(CPB)心脏跳动状态下手术,对照组在CPB心脏停跳下手术,分别于术前及术后2、6、24、48 h采集血标本,检测血清肌酸激酶同工酶(CK-MB)、肌钙蛋白Ⅰ(cTnⅠ)、天冬氨酸氨基转移酶(AST)、乳酸脱氢酶(LDH)含量;记录CPB时间、术后48 h心律失常发生率、残余分流发生率、呼吸机支持时间、ICU滞留时间、术后住院天数.结果 两组术后各时点血清CK-MB、cTnⅠ、AST、LDH含量均显著高于术前(P<0.01),但两组间各时点比较差异无统计学意义(P>0.05);实验组CPB时间较对照组短(P<0.01),其他临床观察指标与对照组比较差异无统计学意义(P>0.05).结论 体外循环心脏不停跳心内直视手术能缩短CPB时间,但手术效果与停跳手术比较差异无统计学意义.%Objective To evaluate the protective effects of cardiac arrest and beating heart on patients with congenital heart disease (CHD).Methods One hundred and sixteen CHD patients were randomly divided into experimental group (beating heart group) and control group (cardioplegia group).The experimental group received surgery on beating heart with cardiopulmonary bypass (CPB),cardiac arrest operation under CPB in the control group,respectively.Blood samples were taken and the serum levels of creatine kinase MB (CK-MB),troponin Ⅰ(cTnⅠ),aspartate aminotransferase (AST),lactate dehydrogenase (LDH) were detected before operation and 2,6,24,48 hours after operation.The clinical parameters including CPB times,incidence of arrhythmia,residual shunt occurred rate,duration of mechanical ventilation,ICU stay time and postoperative hospital stay were detected respectively.Results Postoperatively,the CK

  13. Beat-to-beat cycle length variability of spontaneously beating guinea pig sinoatrial cells: relative contributions of the membrane and calcium clocks.

    Directory of Open Access Journals (Sweden)

    Massimiliano Zaniboni

    Full Text Available The heartbeat arises rhythmically in the sino-atrial node (SAN and then spreads regularly throughout the heart. The molecular mechanism underlying SAN rhythm has been attributed by recent studies to the interplay between two clocks, one involving the hyperpolarization activated cation current If (the membrane clock, and the second attributable to activation of the electrogenic NaCa exchanger by spontaneous sarcoplasmic releases of calcium (the calcium clock. Both mechanisms contain, in principle, sources of beat-to-beat cycle length variability, which can determine the intrinsic variability of SAN firing and, in turn, contribute to the heart rate variability. In this work we have recorded long sequences of action potentials from patch clamped guinea pig SAN cells (SANCs perfused, in turn, with normal Tyrode solution, with the If inhibitor ivabradine (3 µM, then back to normal Tyrode, and again with the ryanodine channels inhibitor ryanodine (3 µM. We have found that, together with the expected increase in beating cycle length (+25%, the application of ivabradine brought about a significant and dramatic increase in beat-to-beat cycle length variability (+50%. Despite the similar effect on firing rate, ryanodine did not modify significantly beat-to-beat cycle length variability. Acetylcholine was also applied and led to a 131% increase of beating cycle length, with only a 70% increase in beat-to-beat cycle length variability. We conclude that the main source of inter-beat variability of SANCs firing rate is related to the mechanism of the calcium clock, whereas the membrane clock seems to act in stabilizing rate. Accordingly, when the membrane clock is silenced by application of ivabradine, stochastic variations of the calcium clock are free to make SANCs beating rhythm more variable.

  14. Heart pacemaker - discharge

    Science.gov (United States)

    ... pacemaker can be used for patients with heart failure. It has three leads to help the heart beat in a more coordinated manner. Some pacemakers also can deliver electric shocks to the heart that can stop life-threatening ...

  15. Do lambs perceive regular human stroking as pleasant? Behavior and heart rate variability analyses.

    Directory of Open Access Journals (Sweden)

    Marjorie Coulon

    Full Text Available Stroking by humans is beneficial to the human-animal relationship and improves welfare in many species that express intraspecific allogrooming, but very few studies have looked at species like sheep that do not express such contact except around parturition. This study investigated the way lambs perceive regular human tactile contact using behavioral and physiological responses. Twenty-four lambs were reared and bucket-fed in groups of four. All were stroked daily by their familiar caregiver. At 8 weeks of age, the lambs were individually tested in their home pen but in a 1×1m open-barred pen after a 15 h period of habituation to physical separation from peers while remaining in visual and auditory contact. Half of the lambs received stroking by their caregiver for 8 min and half were exposed to their caregiver's immobile presence. Heart rate and heart rate variability were recorded and analyzed by 2-min slots over the same interval based on three measures: mean heart rate value (HR, root mean square of successive differences (RMSSD and standard deviation of all intervals measured between consecutive sinus beats (SDNN. Behavioral responses (ear postures of the lamb and time spent in contact with the familiar caregiver, on the knees of the familiar caregiver, and moving were recorded throughout the test. Lamb HR decreased continuously while in the presence of their caregiver. Lambs being stroked showed slower HR and higher RMSSD which reflected positive emotional states compared to lambs left unstroked. All behavioral variables were highly correlated with the main component axis of the PCA analyses: the more the animals stayed in contact with their caregiver, the less they moved and the more their ears were hanging. This first component clearly differentiates lambs being stroked or not. Behavioral and physiological observations support the hypothesis that gentle physical contact with the caregiver is perceived positively by lambs.

  16. 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

  17. 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.

  18. Minimally invasive robotic coronary bypass on the beating heart using da Vinci S system%机器人非体外循环冠状动脉旁路移植术

    Institute of Scientific and Technical Information of China (English)

    高长青; 杨明; 王刚; 吴扬; 赵悦; 李丽霞; 王加利; 肖苍松; 周琪

    2009-01-01

    Objective To summarize the experience of minimally invasive robotic caronary bypass on beating heart using da Vinci S in China. Methods Fifty-six patients underwent selected robotic coronary bypass on beating heart from April 2007 to December 2008. All the patients had history of angina and the coronary arteriography showed severe stenosis in the left anterior descending artery (LAD), of which 10 cases had right coronary artery or left circumflex coronary (LCX) stenosis. The age was 33 to 74 years old, with a mean of (55.8±9. 4) years old. The weight was (71.4 ± 13.2) kg, All the patients had good lung function and had no medical history of pleurisy and thoracic surgery. CT scan of double internal thoracic artery (ITA) was routinely checked preoperatively. The procedures included : (1) The robotically assisted endoscopic atranmatic coronary artery bypass surgery. The approach was via a small left anterior thoracotomy (6 to 8 cm) after robotic ITA was taken down. The ITA was manually anastomosed to the LAD or LCX on beating heart. (2) Totally endoscopic coronary bypass graft on beating heart. After ITA harvesting, the endostabilizer was inserted via the fourth pert in the xiphoid area under endoscopic vision. The left ITA to the LAD grafting was done using U-clips on beating heart in a totally endoscopic manner using da Vinci S system through 4 ports. For all patients the ITA flow was checked by the Doppler flowmeter after anastomosis was completed. After the surgery was completed, the thoracic port was checked carefully to avoid bleeding, The operating procedures and a variety of clinical parameters were recorded and analyzed. (3) Stent placement after robotic surgery in a hybrid manner. The graft pateney rate was evaluated by CT or orteriography. Results All patients successfully accepted robotic minimally invasive coronary bypass on the beating heart using da Vinci S surgical system without complications. The mean graft flow was (23.2 ± 16. 7) mL/min. And

  19. Phase-dependent chronotropic response of the heart during running in humans.

    Science.gov (United States)

    Nomura, Kunihiko; Takei, Yoshiaki; Yoshida, Masaki; Yanagida, Yasuyoshi

    2006-05-01

    Heartbeat modulation by muscle contraction during rhythmic exercise involving a small muscle mass is phase-dependent, reflecting the timing of the muscle contraction within the cardiac cycle, but it remains unclear whether such modulation occurs during whole body exercise. To determine whether phase-dependent chronotropic changes in the heart would occur during running, we investigated the relationship between R-R interval (RRI) and the timing of vastus lateralis muscle contractions within the cardiac cycle. Seven healthy subjects were examined during high intensity running where the target heart rate was 160 beats . min(-1). The running pitch was made to wax and wane periodically in the neighborhood of the target heart rate to scan the effect of footfall timing within the cardiac cycle on heart period. We found that when muscle contraction occurred early in the cardiac cycle, RRI was reduced from the mean RRI (Pincrease (P>0.05). Thus, the curve reflecting this phase-dependent relationship between heart period and timing of muscle contraction showed a positive slope within the first one-quarter to three-quarters of the cardiac cycle. Our results suggest the existence of a mechanism that provides beat-by-beat regulation of RRI even when it is very short (approximately 375 ms), i.e., a cardio-locomotor synchronization develops during running, when the frequencies of the two rhythms approach one another.

  20. Beat-to-beat T-wave amplitude variability in the long QT syndrome.

    Science.gov (United States)

    Extramiana, Fabrice; Tatar, Charif; Maison-Blanche, Pierre; Denjoy, Isabelle; Messali, Anne; Dejode, Patrick; Iserin, Frank; Leenhardt, Antoine

    2010-09-01

    Long QT syndrome (LQTS) is a primary electrical disease characterized by QT prolongation and increased repolarization dispersion leading to T-wave amplitude beat-to-beat changes. We aimed to quantify beat-to-beat T-wave amplitude variability from ambulatory Holter recordings in genotyped LQTS patients. Seventy genotyped LQTS patients (mean age 23 +/- 15 years, 42 males, 50% LQT1, 39% LQT2, and 11% LQT3) and 70 normal matched control subjects underwent a 24-h digital Holter recording. Using the Tvar software (Ela Medical, Sorin group), the beat-to-beat variance of the T-wave amplitude (TAV in microV) [corrected] was assessed on 50-ms consecutive clusters during three 1-h periods: one with around average diurnal heart rate (Day Fast), one nocturnal period (Night), and one diurnal period with around average nocturnal heart rate (Day Slow). TAV was increased in LQTS patients during the two diurnal periods but not at night (during the Day Fast period, mean TAV was 34 +/- 20 microV [corrected] in LQTS patients vs. 27 +/- 10 microV [corrected] in controls, P < 0.05). This effect depended on the genotype. In LQT1, TAV was larger when compared with controls for both Day Fast and Slow periods, but in LQT2 only Day Fast shows higher TAV. Oppositely, in LQT3 the TAV was higher than in the control group during the Day slow period (mean TAV = 34 +/- 20 vs. 25 +/- 8 microV [corrected] in controls, P < 0.05). In genotyped LQTS patients beat-to-beat T-wave amplitude variability was increased when compared with control subjects. That pattern was modulated by circadian influences in a gene-dependent manner.

  1. Scaling Behaviour and Memory in Heart Rate of Healthy Human

    Institute of Scientific and Technical Information of China (English)

    CAI Shi-Min; PENG Hu; YANG Hui-Jie; ZHOU Tao; ZHOU Pei-Ling; WANG Bing-Hong

    2007-01-01

    We investigate a set of complex heart rate time series from healthy human in different behaviour states with the detrended fluctuation analysis and diffusion entropy (DE) method. It is proposed that the scaling properties are influenced by behaviour states. The memory detected by DE exhibits an approximately same pattern after a detrending procedure. Both of them demonstrate the long-range strong correlations in heart rate. These findings may be helpful to understand the underlying dynamical evolution process in the heart rate control system, as well as to model the cardiac dynamic process.

  2. How Live Performance Moves the Human Heart.

    Science.gov (United States)

    Shoda, Haruka; Adachi, Mayumi; Umeda, Tomohiro

    2016-01-01

    We investigated how the audience member's physiological reactions differ as a function of listening context (i.e., live versus recorded music contexts). Thirty-seven audience members were assigned to one of seven pianists' performances and listened to his/her live performances of six pieces (fast and slow pieces by Bach, Schumann, and Debussy). Approximately 10 weeks after the live performance, each of the audience members returned to the same room and listened to the recorded performances of the same pianists' via speakers. We recorded the audience members' electrocardiograms in listening to the performances in both conditions, and analyzed their heart rates and the spectral features of the heart-rate variability (i.e., HF/TF, LF/HF). Results showed that the audience's heart rate was higher for the faster than the slower piece only in the live condition. As compared with the recorded condition, the audience's sympathovagal balance (LF/HF) was less while their vagal nervous system (HF/TF) was activated more in the live condition, which appears to suggest that sharing the ongoing musical moments with the pianist reduces the audience's physiological stress. The results are discussed in terms of the audience's superior attention and temporal entrainment to live performance.

  3. Relationship between ischemic area of coronary heart disease and origin part of ventricular premature beat%冠心病缺血区与室性早搏起源部位之间的关系

    Institute of Scientific and Technical Information of China (English)

    宋红艳; 刘相丽; 许纲

    2012-01-01

    目的 探讨冠心病与室性心律失常的关系.方法 对行冠脉造影并行Holter检查者根据造影结果分成阴性组和阳性组,以冠状动脉狭窄大于或等于70%者为阳性.分析两组Holter结果,主要是分析其室性心律失常数量、形态,记录年龄、性别、高血压史、糖尿病史、心脏彩超及室早治疗方法等.结果 冠心病室性心律失常合并高血压、糖尿病者多于特发性室性早搏,室早消融比例及室早次数多于特发性室早(P<0.05).结论 冠心病室早患者有自身的特点,对其治疗有一定指导意义.%Objective To investigate the relationship between ventricular arrhythmias and coronary heart disease(CHD). Methods The patients who underwent coronary angigraphy(CAG) and Holter were enrolled in the study. All patients were divided into negative and positive groups according to the results of CAG. The stenosis of coronary artery≥70% was positive. The Holter results, age,sex, history of hypertension and diabetes mellitus(DM) ,echocardiographic examination, therapeutic measures were analyzed in the two groups. Results The CHD patients with ventricular arrhythmias complicating hypertension and DM were more than those with idiopatic ventricular premature beat, so did the ratio of catheter ablation and the frequency of ventricular premature beat(P<0. 05). Conclusion The CHD patients complicating ventricular premature beats have own characteristics, which has some guidance significance to choose therapy.

  4. Signaling pathways in failing human heart muscle cells.

    Science.gov (United States)

    Drexler, H; Hasenfuss, G; Holubarsch, C

    1997-07-01

    Experimental studies have delineated important signaling pathways in cardiomyocytes and their alterations in heart failure; however, there is now evidence that these observations are not necessarily applicable to human cardiac muscle cells. For example, angiotensin II (A II) does not exert positive inotropic effects in human ventricular muscle cells, in contrast to observation in rats. Thus, it is important to elucidate cardiac signaling pathways in humans in order to appreciate the functional role of neurohumoral or mechanical stimulation in human myocardium in health and disease. In the present article, we review signal pathways in the failing human heart based on studies in human cardiac tissues and in vivo physiological studies related to A II, nitric oxide, and β-adrenergic stimulation. (Trends Cardiovasc Med 1997; 7:151-160). © 1997, Elsevier Science Inc.

  5. Organization of ventricular fibrillation in the human heart.

    Science.gov (United States)

    Ten Tusscher, Kirsten H W J; Hren, Rok; Panfilov, Alexander V

    2007-06-22

    Sudden cardiac death is a major cause of death in the industrialized world, claiming approximately 300,000 victims annually in the United States alone. In most cases, sudden cardiac death is caused by ventricular fibrillation (VF). Experimental studies in large animal hearts have shown that the uncoordinated contractions during VF are caused by large numbers of chaotically wandering reentrant waves of electrical activity. However, recent clinical data on VF in the human heart seem to suggest that human VF may have a markedly different organization. Here, we use a detailed model of the human ventricles, including a detailed description of cell electrophysiology, ventricular anatomy, and fiber direction anisotropy, to study the organization of human VF. We show that characteristics of our simulated VF are qualitatively similar to the clinical data. Furthermore, we find that human VF is driven by only approximately 10 reentrant sources and thus is much more organized than VF in animal hearts of comparable size, where VF is driven by approximately 50 sources. We investigate the influence of anisotropy ratio, tissue excitability, and restitution properties on the number of reentrant sources driving VF. We find that the number of rotors depends strongest on minimum action potential duration, a property that differs significantly between human and large animal hearts. Based on these findings, we suggest that the simpler spatial organization of human VF relative to VF in large animal hearts may be caused by differences in minimum action potential duration. Both the simpler spatial organization of human VF and its suggested cause may have important implications for treating and preventing this dangerous arrhythmia in humans.

  6. Day-to-day reproducibility of Holter beat-by-beat analysis of repolarisation.

    Science.gov (United States)

    Baranowski, Rafał; Popławska, Wanda; Buchner, Teodor; Chojnowska, Lidia; Rydlewska-Sadowska, Wanda

    2003-06-01

    Reproducibility of Holter QT analysis is not well established and has been assessed only in one study. We evaluated the day-to-day reproducibility of different QT parameters--mean and max (four beats basis) 24h QT and QTc (Bazett formula), QT for heart rate 55-60 [QT60], 75-80 [QT80] and 95-100 [QT100] beats/min and QT/RR slope (calculated in moving window of 3000 beats in 50 beat steps). QT intervals were measured from 48h digital ECG (sampled at 256 Hz) recordings using Del Mar Medical's QT software in beat-to-beat fashion. The analysed group consisted of 6 women and 24 men--13 patients with hypertrophic cardiomyopathy, 5 healthy family members of the patients with hypertrophic cardiomyopathy, 7 patients with CAD and 5 with other diseases (hypertension, arrhythmia, aborted sudden death without organic heart disease). Reproducibility was analysed with the methods proposed by Bland and Altman. The overall reproducibility of repolarisation parameters was acceptable. Coefficient of reproducibility for mean 24h QT was 24ms, mean QTc 12ms, max QT 22ms, max QTc 24ms. The best reproducibility was observed for QT60, QT80 and QT100 - 12ms, respectively. The poorest day-to-day reproducibility was recorded for the QT/RR slope parameters, which was related to lower heart rate reproducibility. We can conclude that day-to-day reproducibility of Holter repolarisation analysis is acceptable. QT measurement in narrow heart rate windows has the best reproducibility. Accurate QT analysis requires good quality recording, T wave amplitude above 0.2mV and an interactive QT measurement tool which includes verification, editing abilities.

  7. Isoproterenol effects evaluated in heart slices of human and rat in comparison to rat heart in vivo

    Energy Technology Data Exchange (ETDEWEB)

    Herrmann, Julia E.; Heale, Jason; Bieraugel, Mike; Ramos, Meg [Drug Safety Evaluation, Allergan Inc., 2525 Dupont Dr, Irvine, CA 92612 (United States); Fisher, Robyn L. [Vitron Inc., Tucson, AZ (United States); Vickers, Alison E.M., E-mail: vickers_alison@allergan.com [Drug Safety Evaluation, Allergan Inc., 2525 Dupont Dr, Irvine, CA 92612 (United States)

    2014-01-15

    Human response to isoproterenol induced cardiac injury was evaluated by gene and protein pathway changes in human heart slices, and compared to rat heart slices and rat heart in vivo. Isoproterenol (10 and 100 μM) altered human and rat heart slice markers of oxidative stress (ATP and GSH) at 24 h. In this in vivo rat study (0.5 mg/kg), serum troponin concentrations increased with lesion severity, minimal to mild necrosis at 24 and 48 h. In the rat and the human heart, isoproterenol altered pathways for apoptosis/necrosis, stress/energy, inflammation, and remodeling/fibrosis. The rat and human heart slices were in an apoptotic phase, while the in vivo rat heart exhibited necrosis histologically and further progression of tissue remodeling. In human heart slices genes for several heat shock 70 kD members were altered, indicative of stress to mitigate apoptosis. The stress response included alterations in energy utilization, fatty acid processing, and the up-regulation of inducible nitric oxide synthase, a marker of increased oxidative stress in both species. Inflammation markers linked with remodeling included IL-1α, Il-1β, IL-6 and TNFα in both species. Tissue remodeling changes in both species included increases in the TIMP proteins, inhibitors of matrix degradation, the gene/protein of IL-4 linked with cardiac fibrosis, and the gene Ccl7 a chemokine that induces collagen synthesis, and Reg3b a growth factor for cardiac repair. This study demonstrates that the initial human heart slice response to isoproterenol cardiac injury results in apoptosis, stress/energy status, inflammation and tissue remodeling at concentrations similar to that in rat heart slices. - Highlights: • Human response to isoproterenol induced cardiac injury evaluated in heart slices. • Isoproterenol altered apoptosis, energy, inflammation and remodeling pathways. • Human model verified by comparison to rat heart slices and rat heart in vivo. • Human and rat respond to isoproterenol

  8. Reorganized PKA-AKAP associations in the failing human heart.

    Science.gov (United States)

    Aye, Thin-Thin; Soni, Siddarth; van Veen, Toon A B; van der Heyden, Marcel A G; Cappadona, Salvatore; Varro, Andras; de Weger, Roel A; de Jonge, Nicolaas; Vos, Marc A; Heck, Albert J R; Scholten, Arjen

    2012-02-01

    Here we reveal that the characterization of large-scale re-arrangements of signaling scaffolds induced by heart failure can serve as a novel concept to identify more specific therapeutic targets. In the mammalian heart, the cAMP pathway, with the cAMP-dependent protein kinase (PKA) in a central role, acts directly downstream of adrenergic receptors to mediate cardiac contractility and rhythm. Heart failure, characterized by severe alterations in adrenergic stimulation is, amongst other interventions, often treated with β-blockers. Contrasting results, however, have shown both beneficial and detrimental effects of decreased cAMP levels in failing hearts. We hypothesize that the origin of this behavior lies in the complex spatiotemporal organization of the regulatory subunit of PKA (PKA-R), which associates tightly with various A-kinase anchoring proteins (AKAPs) to specifically localize PKA's activity. Using chemical proteomics directly applied to human patient and control heart tissue we demonstrate that the association profile of PKA-R with several AKAPs is severely altered in the failing heart, for instance effecting the interaction between PKA and the novel AKAP SPHKAP was 6-fold upregulated upon failing heart conditions. Also a significant increase in captured cGMP-dependent protein kinase (PKG) and phosphodiesterase 2 (PDE2) was observed. The observed altered profiles can already explain many aspects of the aberrant cAMP-response in the failing human heart, validating that this dataset may provide a resource for several novel, more specific, treatment options. This article is part of a Special Issue entitled "Local Signaling in Myocytes".

  9. FISH CONSUMPTION, METHYLMERCURY, AND HUMAN HEART DISEASE.

    Energy Technology Data Exchange (ETDEWEB)

    LIPFERT, F.W.; SULLIVAN, T.M.

    2005-09-21

    Environmental mercury continues to be of concern to public health advocates, both in the U.S. and abroad, and new research continues to be published. A recent analysis of potential health benefits of reduced mercury emissions has opened a new area of public health concern: adverse effects on the cardiovascular system, which could account for the bulk of the potential economic benefits. The authors were careful to include caveats about the uncertainties of such impacts, but they cited only a fraction of the applicable health effects literature. That literature includes studies of the potentially harmful ingredient (methylmercury, MeHg) in fish, as well as of a beneficial ingredient, omega-3 fatty acids or ''fish oils''. The U.S. Food and Drug Administration (FDA) recently certified that some of these fat compounds that are primarily found in fish ''may be beneficial in reducing coronary heart disease''. This paper briefly summarizes and categorizes the extensive literature on both adverse and beneficial links between fish consumption and cardiovascular health, which are typically based on studies of selected groups of individuals (cohorts). Such studies tend to comprise the ''gold standard'' of epidemiology, but cohorts tend to exhibit a great deal of variability, in part because of the limited numbers of individuals involved and in part because of interactions with other dietary and lifestyle considerations. Note that eating fish will involve exposure to both the beneficial effects of fatty acids and the potentially harmful effects of contaminants like Hg or PCBs, all of which depend on the type of fish but tend to be correlated within a population. As a group, the cohort studies show that eating fish tends to reduce mortality, especially due to heart disease, for consumption rates up to about twice weekly, above which the benefits tend to level off. A Finnish cohort study showed increased mortality risks

  10. Heritability of ambulatory and beat-to-beat office blood pressure in large multigenerational Arab pedigrees: the 'Oman Family study'.

    Science.gov (United States)

    Albarwani, Sulayma; Muñoz, M Loretto; Voruganti, V Saroja; Jaju, Deepali; Al-Yahyaee, V Saeed; Rizvi, Syed G; Lopez-Alvarenga, Juan C; Al-Anqoudi, Zahir M; Bayoumi, Riad A; Comuzzie, Anthony G; Snieder, Harold; Hassan, Mohammed O

    2012-12-01

    To estimate the heritability of ambulatory blood pressure (BP), heart rate (HR), and beat-to-beat office BP and HR in an isolated, environmentally and genetically homogeneous Omani Arab population. Ambulatory BP measurements were recorded in 1,124 subjects with a mean age of 33.8 ± 16.2 years, using the auscultatory mode of the validated Schiller ambulatory BP Monitor. Beat-to-beat BP and HR were recorded by the Task Force Monitor. Heritability was estimated using quantitative genetic analysis. This was achieved by applying the maximum-likelihood-based variance decomposition method implemented in SOLAR software. We detected statistically significant heritability estimates for office beat-to-beat, 24-hour, daytime, and sleep HR of 0.31, 0.21, 0.20, and 0.07, respectively. Heritability estimates in the above mentioned conditions for systolic BP (SBP)/diastolic BP (DBP)/mean BP (MBP)were all significant and estimated at 0.19/0.19/0.19, 0.30/0.44/0.41, 0.28/0.38/0.39, and 0.21/0.18/0.20,respectively. Heritability estimates for 24-hour and daytime ambulatory SBP, DBP, and MBP ranged from 0.28 to 0.44, and were higher than the heritability estimates for beat-to-beat recordings and sleep periods,which were estimated within a narrow range of 0.18-0.21. In this cohort, because shared environments are common to all, the environmental influence that occurs is primarily due to the variation in non-shared environment that is unique to the individual. We demonstrated significant heritability estimates for both beat-to-beat office and ambulatory BP and HR recordings, but 24-hour and daytime ambulatory heritabilities are higher than those from beat-to-beat resting levels and ambulatory night-time recordings.

  11. 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 o

  12. 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

  13. From zebrafish heart jogging genes to mouse and human orthologs: using Gene Ontology to investigate mammalian heart development.

    Science.gov (United States)

    Khodiyar, Varsha K; Howe, Doug; Talmud, Philippa J; Breckenridge, Ross; Lovering, Ruth C

    2013-01-01

    For the majority of organs in developing vertebrate embryos, left-right asymmetry is controlled by a ciliated region; the left-right organizer node in the mouse and human, and the Kuppfer's vesicle in the zebrafish. In the zebrafish, laterality cues from the Kuppfer's vesicle determine asymmetry in the developing heart, the direction of 'heart jogging' and the direction of 'heart looping'.  'Heart jogging' is the term given to the process by which the symmetrical zebrafish heart tube is displaced relative to the dorsal midline, with a leftward 'jog'. Heart jogging is not considered to occur in mammals, although a leftward shift of the developing mouse caudal heart does occur prior to looping, which may be analogous to zebrafish heart jogging. Previous studies have characterized 30 genes involved in zebrafish heart jogging, the majority of which have well defined orthologs in mouse and human and many of these orthologs have been associated with early mammalian heart development.    We undertook manual curation of a specific set of genes associated with heart development and we describe the use of Gene Ontology term enrichment analyses to examine the cellular processes associated with heart jogging.  We found that the human, mouse and zebrafish 'heart jogging orthologs' are involved in similar organ developmental processes across the three species, such as heart, kidney and nervous system development, as well as more specific cellular processes such as cilium development and function. The results of these analyses are consistent with a role for cilia in the determination of left-right asymmetry of many internal organs, in addition to their known role in zebrafish heart jogging.    This study highlights the importance of model organisms in the study of human heart development, and emphasises both the conservation and divergence of developmental processes across vertebrates, as well as the limitations of this approach.

  14. Towards real-time 3D US-CT registration on the beating heart for guidance of minimally invasive cardiac interventions

    Science.gov (United States)

    Li, Feng; Lang, Pencilla; Rajchl, Martin; Chen, Elvis C. S.; Guiraudon, Gerard; Peters, Terry M.

    2012-02-01

    Compared to conventional open-heart surgeries, minimally invasive cardiac interventions cause less trauma and sideeffects to patients. However, the direct view of surgical targets and tools is usually not available in minimally invasive procedures, which makes image-guided navigation systems essential. The choice of imaging modalities used in the navigation systems must consider the capability of imaging soft tissues, spatial and temporal resolution, compatibility and flexibility in the OR, and financial cost. In this paper, we propose a new means of guidance for minimally invasive cardiac interventions using 3D real-time ultrasound images to show the intra-operative heart motion together with preoperative CT image(s) employed to demonstrate high-quality 3D anatomical context. We also develop a method to register intra-operative ultrasound and pre-operative CT images in close to real-time. The registration method has two stages. In the first, anatomical features are segmented from the first frame of ultrasound images and the CT image(s). A feature based registration is used to align those features. The result of this is used as an initialization in the second stage, in which a mutual information based registration is used to register every ultrasound frame to the CT image(s). A GPU based implementation is used to accelerate the registration.

  15. Influence of heart failure on nucleolar organization and protein expression in human hearts

    Energy Technology Data Exchange (ETDEWEB)

    Rosello-Lleti, Esther; Rivera, Miguel; Cortes, Raquel [Cardiocirculatory Unit, Research Center, Hospital Universitario La Fe, Valencia (Spain); Azorin, Inmaculada [Experimental Neurology, Research Center, Hospital Universitario La Fe, Valencia (Spain); Sirera, Rafael [Biotechnology Department, Universidad Politecnica, Valencia (Spain); Martinez-Dolz, Luis [Cardiology Unit, Hospital Universitario La Fe, Valencia (Spain); Hove, Leif; Cinca, Juan [Cardiology Unit, Hospital San Pau, Barcelona (Spain); Lago, Francisca; Gonzalez-Juanatey, Jose R. [Cardiology Unit, Institute of Biomedical Research, Hospital Clinicode Santiagode Compostela (Spain); Salvador, Antonio [Experimental Neurology, Research Center, Hospital Universitario La Fe, Valencia (Spain); Portoles, Manuel, E-mail: portoles_man@gva.es [Cell Biology and Pathology Unit, Research Center, Hospital Universitario La Fe, Valencia (Spain)

    2012-02-10

    Highlights: Black-Right-Pointing-Pointer Heart failure alters nucleolar morphology and organization. Black-Right-Pointing-Pointer Nucleolin expression is significant increased in ischemic and dilated cardiomyopathy. Black-Right-Pointing-Pointer Ventricular function of heart failure patients was related with nucleolin levels. -- Abstract: We investigate for the first time the influence of heart failure (HF) on nucleolar organization and proteins in patients with ischemic (ICM) or dilated cardiomyopathy (DCM). A total of 71 human hearts from ICM (n = 38) and DCM (n = 27) patients, undergoing heart transplantation and control donors (n = 6), were analysed by western-blotting, RT-PCR and cell biology methods. When we compared protein levels according to HF etiology, nucleolin was increased in both ICM (117%, p < 0.05) and DCM (141%, p < 0.01). Moreover, mRNA expression were also upregulated in ICM (1.46-fold, p < 0.05) and DCM (1.70-fold, p < 0.05. Immunofluorescence studies showed that the highest intensity of nucleolin was into nucleolus (p < 0.0001), and it was increased in pathological hearts (p < 0.0001). Ultrastructure analysis by electron microscopy showed an increase in the nucleus and nucleolus size in ICM (17%, p < 0.05 and 131%, p < 0.001) and DCM (56%, p < 0.01 and 69%, p < 0.01). Nucleolar organization was influenced by HF irrespective of etiology, increasing fibrillar centers (p < 0.001), perinucleolar chromatin (p < 0.01) and dense fibrillar components (p < 0.01). Finally, left ventricular function parameters were related with nucleolin levels in ischemic hearts (p < 0.0001). The present study demonstrates that HF influences on morphology and organization of nucleolar components, revealing changes in the expression and in the levels of nucleolin protein.

  16. Progress of Anesthetic Management of Robotic Totally Endoscopic Coronary Artery Bypass on Beating Heart%全机器人不停跳冠状动脉旁路移植术的麻醉管理进展

    Institute of Scientific and Technical Information of China (English)

    姚优修(综述); 孟秀丽(审校)

    2015-01-01

    [Summary] Robotic totally endoscopic coronary artery bypass on beating heart (BH-TECAB), a minimally invasive surgical approach with rapid postoperative recovery , is becoming the future trend of minimally invasive coronary surgery , which demands a higher standard for anesthetic management . It comprises pressured pneumothorax , unilateral lung ventilation , transesophageal echocardiography monitoring , hemodynamics maintaining , preparation for cardiopulmonary bypass and conversion to sternotomy , and ventricular fibrillation treatment , which require anesthesiologists to achieve more refined perioperative management and pathophysiological regulation .%全机器人不停跳冠状动脉旁路移植术创伤小,术后恢复快,是未来微创冠状动脉外科的趋势,对麻醉管理提出更高的要求,主要包括加压CO2气胸、单肺通气的应用、经食道超声心动图的监测、术中血流动力学的维持、体外循环及中转开胸手术的准备、室颤的处理等,要求麻醉医师对患者病理生理的调控及围术期的管理达到更精细化。

  17. 从IBM深度问答系统战胜顶尖人类选手所想到的%Thinking about DeepQA beating Human Champions

    Institute of Scientific and Technical Information of China (English)

    黄昌宁

    2011-01-01

    The DeepQA question answering system of IBM beat two human champions on U. S. Jeopardy Show in 14th-16th February, 2011. It obviously shows that Watson, IBM's super computer, outperforms human intelligent behaviors. It is a great milestone in the history of Artificial Intelligence. This paper reviews some gain and loss of natural language processing and automatic question answering technologies. The paper is written for the thirty-year ceremony of the Chinese Information Processing Society of China.%2011年2月14-16日,IBM的深度问答系统在美国Jeopardy电视竞答节目中一举打败该节目的两住前冠军,凸显了计算机在自然语言处理(NLP)技术上超越人类的智能行为,这是人工智能研究历史上意义非凡的里程碑.该文通过这一事件来回顾国内外自然语言处理和自动问答技术研究的某些得失,借此纪念中国中文信息学会成立30周年华诞.

  18. Anatomy of the Heart

    Science.gov (United States)

    ... Share this page from the NHLBI on Twitter. Anatomy of the Heart Your heart is located under your ribcage in the center of your chest between your right and left lungs. Its muscular walls beat, or contract, pumping blood ...

  19. 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.

  20. 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.

  1. Haploinsufficiency of TAB2 causes congenital heart defects in humans

    DEFF Research Database (Denmark)

    Thienpont, Bernard; Zhang, Litu; Postma, Alex V;

    2010-01-01

    Congenital heart defects (CHDs) are the most common major developmental anomalies and the most frequent cause for perinatal mortality, but their etiology remains often obscure. We identified a locus for CHDs on 6q24-q25. Genotype-phenotype correlations in 12 patients carrying a chromosomal deletion...... in cardiac development was further supported by its conserved expression in the developing human and zebrafish heart. Moreover, a critical, dosage-sensitive role during development was demonstrated by the cardiac defects observed upon titrated knockdown of tab2 expression in zebrafish embryos...

  2. Heart research advances using database search engines, Human Protein Atlas and the Sydney Heart Bank.

    Science.gov (United States)

    Li, Amy; Estigoy, Colleen; Raftery, Mark; Cameron, Darryl; Odeberg, Jacob; Pontén, Fredrik; Lal, Sean; Dos Remedios, Cristobal G

    2013-10-01

    This Methodological Review is intended as a guide for research students who may have just discovered a human "novel" cardiac protein, but it may also help hard-pressed reviewers of journal submissions on a "novel" protein reported in an animal model of human heart failure. Whether you are an expert or not, you may know little or nothing about this particular protein of interest. In this review we provide a strategic guide on how to proceed. We ask: How do you discover what has been published (even in an abstract or research report) about this protein? Everyone knows how to undertake literature searches using PubMed and Medline but these are usually encyclopaedic, often producing long lists of papers, most of which are either irrelevant or only vaguely relevant to your query. Relatively few will be aware of more advanced search engines such as Google Scholar and even fewer will know about Quertle. Next, we provide a strategy for discovering if your "novel" protein is expressed in the normal, healthy human heart, and if it is, we show you how to investigate its subcellular location. This can usually be achieved by visiting the website "Human Protein Atlas" without doing a single experiment. Finally, we provide a pathway to discovering if your protein of interest changes its expression level with heart failure/disease or with ageing. Crown Copyright © 2013. Published by Elsevier B.V. All rights reserved.

  3. Off beat: pluralizing rhythm

    NARCIS (Netherlands)

    Hoogstad, J.H.; Stougaard Pedersen, B.

    2013-01-01

    Off Beat: Pluralizing Rhythm draws attention to rhythm as a tool for analyzing various cultural objects. In fields as diverse as music, culture, nature, and economy, rhythm can be seen as a phenomenon that both connects and divides. It suggests a certain measure with which people, practices, and cul

  4. Stem cell markers in the heart of the human newborn

    Directory of Open Access Journals (Sweden)

    Armando Faa

    2016-07-01

    Full Text Available The identification of cardiac progenitor cells in mammals raises the possibility that the human heart contains a population of stem cells capable of generating cardiomyocytes and coronary vessels. Several recent studies now show that the different cell types that characterize the adult human heart arise from a common ancestor. Human cardiac stem cells differentiate into cardiomyocytes, and, in lesser extent, into smooth muscle and endothelial cells. The characterization of human cardiac stem cells (CSCs has important clinical implications. In recent years, CD117 (c-kit has been reported to mark a subtype of stem/progenitor cells in the human heart, with stem cell-like properties, including the ability to self-renewal and clonogenicity multipotentiality. Proceedings of the 2nd International Course on Perinatal Pathology (part of the 11th International Workshop on Neonatology · October 26th-31st, 2015 · Cagliari (Italy · October 31st, 2015 · Stem cells: present and future Guest Editors: Gavino Faa, Vassilios Fanos, Antonio Giordano

  5. Heart Failure in Children and Adolescents

    Science.gov (United States)

    ... the heart to beat too slow or too fast. Sometimes one of the heart valves does not open properly causing pressure to back up inside the heart chambers. Rarely, severe chest trauma may damage the heart. Children with muscular dystrophy ...

  6. 心脏不停跳主动脉瓣及联合瓣膜替换术%Aortic and mitral valve replacement with retrograde perfusion in the beating heart

    Institute of Scientific and Technical Information of China (English)

    林辉; 何巍; 刘唐威; 覃家锦; 罗玉忠; 廖寿合; 郑宝石

    2001-01-01

    Objective To estimate the value of aortic valves and combined mitral valve replacement with retrograde perfusion in beating hearts.Methods Continuous retrograde coronary sinus perfusion with beating hearts was used in 83 patients undergoing aortic valve or aortic valve combined with mitral valve replacement,without application of cardioplegia.After aortic valve replacement,the retrograde perfusion wes changed to antegrade perfusion for mitral valve replacement or correction of the other deformities(group A).Cold blood cardioplegia solution(15℃)was infused at intervals in 20 cases(group B).The following parameters were tested:lactate,ET,CTn-T and MDA in blood;myocardial ultra-structure;and cardiac rhythm and cardiac output (co).Results All biochemical values increased after cardiopulmonary bypass(P < 0.05 - 0.01).Empty and beating heart sinus rhythm was maintained in group A.Myocardial ultrastructure did not change significantly.The pump was stopped smoothly as the surgical procedure finished.No postoperative low cardiac output syndrome or arrhythmia was observed.Eight-one patients recovered smoothly,two died from renal failure or infective shock.When the pump stopped,all patients in group B were supported by 5 - 10 μg· kg-1· min-1 dopamine.Transient pacing was used in 9 patients.One patient died from low cardiac output syndrome.Conclusion This method is a good myocardial protection which simulates physiologic status.It is applicable to aortic valve and combined mitral valve replacement of patients with large heart or heart failure and long time aortic cross-clamping.Ideal clinical effect can be achieved.%目的评价逆行灌注心脏不停跳主动脉瓣及联合瓣膜替换术的价值.方法经冠状静脉窦逆行持续灌注机器氧合血,使心脏在有节律的空跳中完成主动脉瓣和二尖瓣替换,或改为非置管顺行灌注,再行二尖瓣替换或其他合并症的处理,共83例(A组);随机选择20例在间歇灌注冷血K+心停搏

  7. 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.

  8. Nonlinear Control of Heart Rate Variability in Human Infants

    Science.gov (United States)

    Sugihara, George; Allan, Walter; Sobel, Daniel; Allan, Kenneth D.

    1996-03-01

    Nonlinear analyses of infant heart rhythms reveal a marked rise in the complexity of the electrocardiogram with maturation. We find that normal mature infants (gestation >= 35 weeks) have complex and distinctly nonlinear heart rhythms (consistent with recent reports for healthy adults) but that such nonlinearity is lacking in preterm infants (gestation parasympathetic-sympathetic interaction and function are presumed to be less well developed. Our study further shows that infants with clinical brain death and those treated with atropine exhibit a similar lack of nonlinear feedback control. These three lines of evidence support the hypothesis championed by Goldberger et al. [Goldberger, A. L., Rigney, D. R. & West, B. J. (1990) Sci. Am. 262, 43-49] that autonomic nervous system control underlies the nonlinearity and possible chaos of normal heart rhythms. This report demonstrates the acquisition of nonlinear heart rate dynamics and possible chaos in developing human infants and its loss in brain death and with the administration of atropine. It parallels earlier work documenting changes in the variability of heart rhythms in each of these cases and suggests that nonlinearity may provide additional power in characterizing physiological states.

  9. In vivo CH3(CH2)11SAu SAM electrodes in the beating heart: in situ analytical studies relevant to pacemakers and interstitial biosensors.

    Science.gov (United States)

    Chou, Howard A; Zavitz, Daniel H; Ovadia, Marc

    2003-01-01

    To study in vivo modification of the SAM equivalent circuit when a highly ordered SAM is used as a bioelectrode, dodecanethiolate SAM-Au intramuscular electrodes were studied in living rat heart in a challenging in situ perfused rat model by impedance spectroscopy, cyclic voltammetry, and neutron activation analysis (NAA). The SAM layer experienced disintegration in vivo biological system, as NAA detected the presence of Au atoms that had leached into the surrounding living tissue. Therefore, the underlying Au surface became exposed during biological implant. Study by impedance spectroscopy, however, revealed perfect capacitive behavior for the SAM, similar to in vitro behavior. Electrodes showed a pure capacitive Nyquist plot with 86.1-89.4 degrees near-vertical line segments as the equivalent circuit locus, as for a parallel plate capacitor. Impedance magnitude varied linearly with 1/omega excluding diffusionally limited ionic charge transport. There was no diffusional conductive element Z(W infinity ) or spatially confined Warburg impedance Z(D). The effect of in vivo exposure of a highly ordered SAM is a 'sealing over' effect of new defects by the binding of proteinaceous or lipid species in the biological milieu, a fact of significance for SAM electrodes used either as pacemaker electrodes or as a platform for in vivo biosensors.

  10. Fusion beat in patients with heart failure treated with left ventricular pacing: may ECG morphology relate to mechanical synchrony? A pilot study

    Directory of Open Access Journals (Sweden)

    Sassone Biagio

    2008-01-01

    Full Text Available Abstract Background Electrical fusion between left ventricular pacing and spontaneous right ventricular activation is considered the key to resynchronisation in sinus rhythm patients treated with single-site left ventricular pacing. Aim Use of QRS morphology to optimize device programming in patients with heart failure (HF, sinus rhythm (SR, left bundle branch block (LBBB, treated with single-site left ventricular pacing. Methods and Results We defined the "fusion band" (FB as the range of AV intervals within which surface ECG showed an intermediate morphology between the native LBBB and the fully paced right bundle branch block patterns. Twenty-four patients were enrolled. Echo-derived parameters were collected in the FB and compared with the basal LBBB condition. Velocity time integral and ejection time did not improve significantly. Diastolic filling time, ejection fraction and myocardial performance index showed a statistically significant improvement in the FB. Interventricular delay and mitral regurgitation progressively and significantly decreased as AV delay shortened in the FB. The tissue Doppler asynchrony index (Ts-SD-12-ejection showed a non significant decreasing trend in the FB. The indications provided by the tested parameters were mostly concordant in that part of the FB corresponding to the shortest AV intervals. Conclusion Using ECG criteria based on the FB may constitute an attractive option for a safe, simple and rapid optimization of resynchronization therapy in patients with HF, SR and LBBB.

  11. A new method for change-point detection developed for on-line analysis of the heart beat variability during sleep

    Science.gov (United States)

    Staudacher, M.; Telser, S.; Amann, A.; Hinterhuber, H.; Ritsch-Marte, M.

    2005-04-01

    We present a novel scaling-dependent measure for times series analysis, the progressive detrended fluctuation analysis (PDFA). Since this method progressively includes and analyzes all data points of the time series, it is suitable for on-line change-point detection: Sudden changes in the statistics of the data points, in the type of correlation or in the statistical variance, or both, are reliably indicated and localized in time. This is first shown for numerous artificially generated data sets of Gaussian random numbers. Also time series with various non-stationarities, such as non-polynomial trends and “spiking”, are included as examples. Although generally applicable, our method was specifically developed as a tool for numerical sleep evaluation based on heart rate variability in the ECG-channel of polysomnographic whole night recordings. It is demonstrated that PDFA can detect specific sleep stage transitions, typically ascending transitions involving sympathetic activation as for example short episodes of wakefulness, and that the method is capable to discern between NREM sleep and REM sleep.

  12. 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

    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...... was similarly increased from rest during PEI-M and further elevated during PEI-H (P Collectively, these findings suggest that the muscle metaboreflex increases cardiac SNA during PEI in humans; however, it requires a robust muscle metaboreflex activation to offset the influence...

  13. Second heart field and the development of the outflow tract in human embryonic heart.

    Science.gov (United States)

    Yang, Yan-Ping; Li, Hai-Rong; Cao, Xi-Mei; Wang, Qin-Xue; Qiao, Cong-Jin; Ya, Jing

    2013-04-01

    The second heart field (SHF) is indicated to contribute to the embryonic heart development. However, less knowledge is available about SHF development of human embryo due to the difficulty of collecting embryos. In this study, serial sections of human embryos from Carnegie stage 10 (CS10) to CS16 were stained with antibodies against Islet-1 (Isl-1), Nkx2.5, GATA4, myosin heavy chain (MHC) and α-smooth muscle actin (α-SMA) to observe spatiotemporal distribution of SHF and its contribution to the development of the arterial pole of cardiac tube. Our findings suggest that during CS10 to CS12, SHF of the human embryo is composed of the bilateral pharyngeal mesenchyme, the central mesenchyme of the branchial arch and splanchnic mesoderm of the pericardial cavity dorsal wall. With development, SHF translocates and consists of ventral pharyngeal mesenchyme and dorsal wall of the pericardial cavity. Hence, the SHF of human embryo shows a dynamic spatiotemporal distribution pattern. The formation of the Isl-1 positive condense cell prongs provides an explanation for the saddle structure formation at the distal pole of the outflow tract. In human embryo, the Isl-1 positive cells of SHF may contribute to the formation of myocardial outflow tract (OFT) and the septum during different development stages.

  14. Totally robotic atrial septal defect closure using da vinci S surgical system on beating heart%全机器人心脏不停跳下房间隔缺损修补术

    Institute of Scientific and Technical Information of China (English)

    杨明; 高长青; 肖苍松; 王刚; 王加利

    2011-01-01

    目的 总结使用"达芬奇S"(da Vinci S)机器人手术系统,心脏不停跳下房间隔缺损修补或房间隔缺损修补+三尖瓣成形术的经验体会.方法 2009年3月至2010年12月,使用da Vinic S机器人系统,心脏不停跳下完成继发孔型房间隔缺损修补或房间隔缺损修补+三尖瓣成形术40例.患者女23例,男17例;年龄平均(38±13)岁.房间隔缺损直径为1.5~3.5 cm,平均(2.8±1.3)cm,无右向左分流,伴有或不伴有三尖瓣重度关闭不全.手术经股动、静脉及右侧颈内静脉插管建立体外循环.于右侧胸壁打直径为0.8 cm的器械臂孔3个,直径为2 cm工作孔1个,术中不阻断升主动脉,经内窥镜套管持续给予二氧化碳,心脏跳动下,术者于操作台前遥控机器人进行房间隔缺损修补,三尖瓣重度关闭不全患者同期行三尖瓣成形术.其中直接缝合房间隔缺损22例,心包补片修补房间隔缺损18例,同期三尖瓣成形9例.术中食管超声评估修补及三尖瓣成形效果.对比不停跳与心脏停跳下全机器人房间隔缺损修补术的手术时间及体外循环时间.结果 所有患者均成功接受全机器人心脏不停跳下房间隔缺损修补术或房间隔缺损修补+三尖瓣成形术,无体循环气体栓子及残余分流等并发症.不停跳组的手术时间、机器人使用时间或体外循环时间少于停跳组.结论 机器人心脏不停跳下房间隔缺损修补术无需阻断升主动脉,简化了全机器人手术过程,手术效果安全可靠.%Objective To Summary the first 40 cases underwent robotic atrial septal defect (ASD) closure or atrial septal defect closure combined bicuspid valve plasty (TVP) using "da Vinci S" surgical System on beating heart. Methods 40 cases of atrial septal defect or combined sever tricuspid valve regurgitation were repaired using "da Vinic S" surgical system on beating heart from March 2009 to December 2010 in cardiovascular department of PLA general

  15. Binaural auditory beats affect vigilance performance and mood.

    Science.gov (United States)

    Lane, J D; Kasian, S J; Owens, J E; Marsh, G R

    1998-01-01

    When two tones of slightly different frequency are presented separately to the left and right ears the listener perceives a single tone that varies in amplitude at a frequency equal to the frequency difference between the two tones, a perceptual phenomenon known as the binaural auditory beat. Anecdotal reports suggest that binaural auditory beats within the electroencephalograph frequency range can entrain EEG activity and may affect states of consciousness, although few scientific studies have been published. This study compared the effects of binaural auditory beats in the EEG beta and EEG theta/delta frequency ranges on mood and on performance of a vigilance task to investigate their effects on subjective and objective measures of arousal. Participants (n = 29) performed a 30-min visual vigilance task on three different days while listening to pink noise containing simple tones or binaural beats either in the beta range (16 and 24 Hz) or the theta/delta range (1.5 and 4 Hz). However, participants were kept blind to the presence of binaural beats to control expectation effects. Presentation of beta-frequency binaural beats yielded more correct target detections and fewer false alarms than presentation of theta/delta frequency binaural beats. In addition, the beta-frequency beats were associated with less negative mood. Results suggest that the presentation of binaural auditory beats can affect psychomotor performance and mood. This technology may have applications for the control of attention and arousal and the enhancement of human performance.

  16. The Sydney Heart Bank: improving translational research while eliminating or reducing the use of animal models of human heart disease.

    Science.gov (United States)

    Dos Remedios, C G; Lal, S P; Li, A; McNamara, J; Keogh, A; Macdonald, P S; Cooke, R; Ehler, E; Knöll, R; Marston, S B; Stelzer, J; Granzier, H; Bezzina, C; van Dijk, S; De Man, F; Stienen, G J M; Odeberg, J; Pontén, F; Linke, W; van der Velden, J

    2017-08-14

    The Sydney Heart Bank (SHB) is one of the largest human heart tissue banks in existence. Its mission is to provide high-quality human heart tissue for research into the molecular basis of human heart failure by working collaboratively with experts in this field. We argue that, by comparing tissues from failing human hearts with age-matched non-failing healthy donor hearts, the results will be more relevant than research using animal models, particularly if their physiology is very different from humans. Tissue from heart surgery must generally be used soon after collection or it significantly deteriorates. Freezing is an option but it raises concerns that freezing causes substantial damage at the cellular and molecular level. The SHB contains failing samples from heart transplant patients and others who provided informed consent for the use of their tissue for research. All samples are cryopreserved in liquid nitrogen within 40 min of their removal from the patient, and in less than 5-10 min in the case of coronary arteries and left ventricle samples. To date, the SHB has collected tissue from about 450 failing hearts (>15,000 samples) from patients with a wide range of etiologies as well as increasing numbers of cardiomyectomy samples from patients with hypertrophic cardiomyopathy. The Bank also has hearts from over 120 healthy organ donors whose hearts, for a variety of reasons (mainly tissue-type incompatibility with waiting heart transplant recipients), could not be used for transplantation. Donor hearts were collected by the St Vincent's Hospital Heart and Lung transplantation team from local hospitals or within a 4-h jet flight from Sydney. They were flushed with chilled cardioplegic solution and transported to Sydney where they were quickly cryopreserved in small samples. Failing and/or donor samples have been used by more than 60 research teams around the world, and have resulted in more than 100 research papers. The tissues most commonly requested are

  17. The human heart: application of the golden ratio and angle.

    Science.gov (United States)

    Henein, Michael Y; Zhao, Ying; Nicoll, Rachel; Sun, Lin; Khir, Ashraf W; Franklin, Karl; Lindqvist, Per

    2011-08-04

    The golden ratio, or golden mean, of 1.618 is a proportion known since antiquity to be the most aesthetically pleasing and has been used repeatedly in art and architecture. Both the golden ratio and the allied golden angle of 137.5° have been found within the proportions and angles of the human body and plants. In the human heart we found many applications of the golden ratio and angle, in addition to those previously described. In healthy hearts, vertical and transverse dimensions accord with the golden ratio, irrespective of different absolute dimensions due to ethnicity. In mild heart failure, the ratio of 1.618 was maintained but in end-stage heart failure the ratio significantly reduced. Similarly, in healthy ventricles mitral annulus dimensions accorded with the golden ratio, while in dilated cardiomyopathy and mitral regurgitation patients the ratio had significantly reduced. In healthy patients, both the angles between the mid-luminal axes of the pulmonary trunk and the ascending aorta continuation and between the outflow tract axis and continuation of the inflow tract axis of the right ventricle approximate to the golden angle, although in severe pulmonary hypertension, the angle is significantly increased. Hence the overall cardiac and ventricular dimensions in a normal heart are consistent with the golden ratio and angle, representing optimum pump structure and function efficiency, whereas there is significant deviation in the disease state. These findings could have anatomical, functional and prognostic value as markers of early deviation from normality. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

  18. 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

  19. Anatomically accurate high resolution modeling of human whole heart electromechanics: A strongly scalable algebraic multigrid solver method for nonlinear deformation

    Science.gov (United States)

    Augustin, Christoph M.; Neic, Aurel; Liebmann, Manfred; Prassl, Anton J.; Niederer, Steven A.; Haase, Gundolf; Plank, Gernot

    2016-01-01

    Electromechanical (EM) models of the heart have been used successfully to study fundamental mechanisms underlying a heart beat in health and disease. However, in all modeling studies reported so far numerous simplifications were made in terms of representing biophysical details of cellular function and its heterogeneity, gross anatomy and tissue microstructure, as well as the bidirectional coupling between electrophysiology (EP) and tissue distension. One limiting factor is the employed spatial discretization methods which are not sufficiently flexible to accommodate complex geometries or resolve heterogeneities, but, even more importantly, the limited efficiency of the prevailing solver techniques which is not sufficiently scalable to deal with the incurring increase in degrees of freedom (DOF) when modeling cardiac electromechanics at high spatio-temporal resolution. This study reports on the development of a novel methodology for solving the nonlinear equation of finite elasticity using human whole organ models of cardiac electromechanics, discretized at a high para-cellular resolution. Three patient-specific, anatomically accurate, whole heart EM models were reconstructed from magnetic resonance (MR) scans at resolutions of 220 μm, 440 μm and 880 μm, yielding meshes of approximately 184.6, 24.4 and 3.7 million tetrahedral elements and 95.9, 13.2 and 2.1 million displacement DOF, respectively. The same mesh was used for discretizing the governing equations of both electrophysiology (EP) and nonlinear elasticity. A novel algebraic multigrid (AMG) preconditioner for an iterative Krylov solver was developed to deal with the resulting computational load. The AMG preconditioner was designed under the primary objective of achieving favorable strong scaling characteristics for both setup and solution runtimes, as this is key for exploiting current high performance computing hardware. Benchmark results using the 220 μm, 440 μm and 880 μm meshes demonstrate

  20. Rotationally acquired 4D-optical coherence tomography of embryonic chick hearts using retrospective gating on the common central A-scan

    DEFF Research Database (Denmark)

    Thommes, Jan; Happel, Christoph M.; Thrane, Lars

    2010-01-01

    In vivo analysis of cardiac physiology and non-invasive imaging of the beating early embryonic heart in 2 and 3D remain a challenge in cardiovascular development research. 3D-imaging of the beating heart relies on gating of the acquired images according to the cardiac cycle. Mostly ECG triggering...... is used for this purpose, e.g. in MRT or CT of human hearts. For visualization of embryonic chick hearts with high-resolution optical coherence tomography (OCT), a gating trigger generated by laser Doppler velocimetry has been successfully demonstrated (1). But this takes time and adds to system...... complexity. More recently, retrospective gating technologies were described (2; 3). In these studies, a time series of 2D images at several positions along the heart volume was used to produce a time sequence of 3D volumes of the beating heart. Rearrangement and validation of the asynchronously acquired...

  1. 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.

  2. Scale Invariant Properties in Heart Rate Signals

    Science.gov (United States)

    Makowiec, D.; Dudkowska, A.; Zwierz, M.; Galaska, R.; Rynkiewicz, A.

    2006-05-01

    The rate of heart beat is controlled by autonomic nervous system: accelerated by the sympathetic system and slowed by the parasympathetic system. Scaling properties in heart rate are usually related to the intrinsic dynamics of this physiological regulatory system. The two packages calculating local exponent spectra: Wavelet Transform Modulus Maxima and Multifractal Detrended Fluctuation Analysis (accessible from Physionet home page http://circ.ahajournals.org/cgi/content/full/101/23/e215) are tested, and then used to investigate the spectrum of singularity exponents in series of heart rates obtained from patients suffering from reduced left ventricle systolic function. It occurs that this state of a heart could be connected to some perturbation in the regulatory system, because the heart rate appears to be less controlled than in a healthy human heart. The multifractality in the heart rate signal is weakened: the spectrum is narrower and moved to higher values what indicate the higher activity of the sympatethic nervous system.

  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 sodium reduction...

  4. Arrhythmogenic remodelling of activation and repolarization in the failing human heart.

    Science.gov (United States)

    Holzem, Katherine M; Efimov, Igor R

    2012-11-01

    Heart failure is a major cause of disability and death worldwide, and approximately half of heart failure-related deaths are sudden and presumably due to ventricular arrhythmias. Patients with heart failure have been shown to be at 6- to 9-fold increased risk of sudden cardiac death compared to the general population. (AHA. Heart Disease and Stroke Statistics-2003 Update. Heart and Stroke Facts. Dallas, TX: American Heart Association; 2002) Thus, electrophysiological remodelling associated with heart failure is a leading cause of disease mortality and has been a major investigational focus examined using many animal models of heart failure. While these studies have provided an important foundation for understanding the arrhythmogenic pathophysiology of heart failure, the need for corroborating studies conducted on human heart tissue has been increasingly recognized. Many human heart studies of conduction and repolarization remodelling have now been published and shed some light on important, potentially arrhythmogenic, changes in human heart failure. These studies are being conducted at multiple experimental scales from isolated cells to whole-tissue preparations and have provided insight into regulatory mechanisms such as decreased protein expression, alternative mRNA splicing of ion channel genes, and defective cellular trafficking. Further investigations of heart failure in the human myocardium will be essential for determining possible therapeutic targets to prevent arrhythmia in heart failure and for facilitating the translation of basic research findings to the clinical realm.

  5. A point-process model of human heartbeat intervals: new definitions of heart rate and heart rate variability.

    Science.gov (United States)

    Barbieri, Riccardo; Matten, Eric C; Alabi, Abdulrasheed A; Brown, Emery N

    2005-01-01

    Heart rate is a vital sign, whereas heart rate variability is an important quantitative measure of cardiovascular regulation by the autonomic nervous system. Although the design of algorithms to compute heart rate and assess heart rate variability is an active area of research, none of the approaches considers the natural point-process structure of human heartbeats, and none gives instantaneous estimates of heart rate variability. We model the stochastic structure of heartbeat intervals as a history-dependent inverse Gaussian process and derive from it an explicit probability density that gives new definitions of heart rate and heart rate variability: instantaneous R-R interval and heart rate standard deviations. We estimate the time-varying parameters of the inverse Gaussian model by local maximum likelihood and assess model goodness-of-fit by Kolmogorov-Smirnov tests based on the time-rescaling theorem. We illustrate our new definitions in an analysis of human heartbeat intervals from 10 healthy subjects undergoing a tilt-table experiment. Although several studies have identified deterministic, nonlinear dynamical features in human heartbeat intervals, our analysis shows that a highly accurate description of these series at rest and in extreme physiological conditions may be given by an elementary, physiologically based, stochastic model.

  6. Impaired mitochondrial function in chronically ischemic human heart

    DEFF Research Database (Denmark)

    Stride, Nis Ottesen; Larsen, Steen; Hey-Mogensen, Martin

    2013-01-01

    mitochondrial damage, hereby reinforcing a vicious circle. Ischemic preconditioning has been proven protective in acute ischemia, but the subject of chronic ischemic preconditioning has not been explored in humans. We hypothesized that mitochondrial respiratory capacity would be diminished in chronic ischemic...... regions of human myocardium but that these mitochondria would be more resistant to ex vivo ischemia and, second, that ROS generation would be higher in ischemic myocardium. The aim of this study was to test mitochondrial respiratory capacity during hyperoxia and hypoxia, to investigate ROS production......, and finally to assess myocardial antioxidant levels. Mitochondrial respiration in biopsies from ischemic and nonischemic regions from the left ventricle of the same heart was compared in nine human subjects. Maximal oxidative phosphorylation capacity in fresh muscle fibers was lower in ischemic compared...

  7. Resonant Bloch-wave beatings.

    Science.gov (United States)

    Kartashov, Yaroslav V; Vysloukh, Victor A; Torner, Lluis

    2014-07-01

    We introduce Bloch-wave beatings in arrays of multimode periodically bent waveguides with a transverse refractive index gradient. The new phenomenon manifests itself in the periodic drastic increase of the amplitude of the Bloch oscillations that accompanies resonant conversion of modes guided by the individual waveguides. The Bloch-wave beatings are found to be most pronounced when the length of the resonant mode conversion substantially exceeds the longitudinal period of the Bloch oscillations. The beating frequency decreases when the amplitude of waveguide bending decreases, while the beating amplitude is restricted by the amplitude of the Bloch oscillations that emerge from the second allowed band of the Floquet-Bloch lattice spectrum.

  8. Resonant Bloch-wave beatings

    CERN Document Server

    Kartashov, Yaroslav V; Torner, Lluis

    2014-01-01

    We introduce Bloch-wave beatings in arrays of multimode periodically bent waveguides with a transverse refractive index gradient. The new phenomenon manifests itself in the periodic drastic increase of the amplitude of the Bloch oscillations that accompanies resonant conversion of modes guided by the individual waveguides. The Bloch-wave beatings are found to be most pronounced when the length of the resonant mode conversion substantially exceeds the longitudinal period of the Bloch oscillations. The beating frequency decreases when the amplitude of waveguide bending decreases, while the beating amplitude is restricted by the amplitude of the Bloch oscillations that emerge from the second allowed band of the Floquet-Bloch lattice spectrum.

  9. IRAN THE BEATING HEART OF ASIA

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    @@ Iran is a vast country covering 1,648,000 square kilometers in southwestern Asia. Its neighbors are Turkmenistan, Azerbaijan and Armenia on the north, Afghanistan and Pakistan on the east, and Turkey and Iraq on the west.

  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. Open Kazakhstan, the Beating Heart of Eurasia

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    @@ Kazakhstan lies in the north of the central Asian republics and is bounded by Russia in the north, China in the east, Kyrgyzstan and Uzbekistan in the south, and the Caspian Sea and part of Turkmenistan in the west. It has almost 1,177 mi (about 1,894 km) of coastline on the Caspian Sea.

  12. 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.

  13. Myocardial commitment from human pluripotent stem cells: Rapid production of human heart grafts.

    Science.gov (United States)

    Garreta, Elena; de Oñate, Lorena; Fernández-Santos, M Eugenia; Oria, Roger; Tarantino, Carolina; Climent, Andreu M; Marco, Andrés; Samitier, Mireia; Martínez, Elena; Valls-Margarit, Maria; Matesanz, Rafael; Taylor, Doris A; Fernández-Avilés, Francisco; Izpisua Belmonte, Juan Carlos; Montserrat, Nuria

    2016-08-01

    Genome editing on human pluripotent stem cells (hPSCs) together with the development of protocols for organ decellularization opens the door to the generation of autologous bioartificial hearts. Here we sought to generate for the first time a fluorescent reporter human embryonic stem cell (hESC) line by means of Transcription activator-like effector nucleases (TALENs) to efficiently produce cardiomyocyte-like cells (CLCs) from hPSCs and repopulate decellularized human heart ventricles for heart engineering. In our hands, targeting myosin heavy chain locus (MYH6) with mCherry fluorescent reporter by TALEN technology in hESCs did not alter major pluripotent-related features, and allowed for the definition of a robust protocol for CLCs production also from human induced pluripotent stem cells (hiPSCs) in 14 days. hPSCs-derived CLCs (hPSCs-CLCs) were next used to recellularize acellular cardiac scaffolds. Electrophysiological responses encountered when hPSCs-CLCs were cultured on ventricular decellularized extracellular matrix (vdECM) correlated with significant increases in the levels of expression of different ion channels determinant for calcium homeostasis and heart contractile function. Overall, the approach described here allows for the rapid generation of human cardiac grafts from hPSCs, in a total of 24 days, providing a suitable platform for cardiac engineering and disease modeling in the human setting.

  14. ZebraBeat: a flexible platform for the analysis of the cardiac rate in zebrafish embryos

    Science.gov (United States)

    de Luca, Elisa; Zaccaria, Gian Maria; Hadhoud, Marwa; Rizzo, Giovanna; Ponzini, Raffaele; Morbiducci, Umberto; Santoro, Massimo Mattia

    2014-05-01

    Heartbeat measurement is important in assesssing cardiac function because variations in heart rhythm can be the cause as well as an effect of hidden pathological heart conditions. Zebrafish (Danio rerio) has emerged as one of the most useful model organisms for cardiac research. Indeed, the zebrafish heart is easily accessible for optical analyses without conducting invasive procedures and shows anatomical similarity to the human heart. In this study, we present a non-invasive, simple, cost-effective process to quantify the heartbeat in embryonic zebrafish. To achieve reproducibility, high throughput and flexibility (i.e., adaptability to any existing confocal microscope system and with a user-friendly interface that can be easily used by researchers), we implemented this method within a software program. We show here that this platform, called ZebraBeat, can successfully detect heart rate variations in embryonic zebrafish at various developmental stages, and it can record cardiac rate fluctuations induced by factors such as temperature and genetic- and chemical-induced alterations. Applications of this methodology may include the screening of chemical libraries affecting heart rhythm and the identification of heart rhythm variations in mutants from large-scale forward genetic screens.

  15. Newborn infants detect the beat in music.

    Science.gov (United States)

    Winkler, István; Háden, Gábor P; Ladinig, Olivia; Sziller, István; Honing, Henkjan

    2009-02-17

    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 origin of music. Theorists are divided on the issue whether this ability is innate or learned. We show that newborn infants develop expectation for the onset of rhythmic cycles (the downbeat), even when it is not marked by stress or other distinguishing spectral features. Omitting the downbeat elicits brain activity associated with violating sensory expectations. Thus, our results strongly support the view that beat perception is innate.

  16. Masses for Galactic Beat Cepheids

    Science.gov (United States)

    D'Cruz, Noella L.; Morgan, Siobahn M.; Böhm-Vitense, Erika

    2000-08-01

    Accurate mass determinations for Cepheids may be used to determine the degree of excess mixing in the interiors of their main-sequence progenitors: the larger the excess mixing, the larger the luminosity of the Cepheid of a given mass, or the smaller the mass of a Cepheid with given luminosity. Dynamical masses determined recently for a few Cepheid binaries indicate excess mixing somewhat stronger than that corresponding to the convective overshoot models by Schaller et al. Beat Cepheids can be used similarly to test main-sequence mixing in stellar interiors. The period ratios for beat Cepheids depend on luminosity, Teff, heavy element abundance, and mass. By comparing pulsational models and the observationally derived luminosity, Teff, metallicities, and period ratios it is possible to obtain masses for these stars, the so-called beat masses. With the old opacities masses much smaller than the evolutionary masses were obtained. With the new OPAL opacities a beat mass close to the dynamical mass was obtained for the binary beat Cepheid Y Carinae, showing that it is now possible to obtain reliable beat masses. In this paper, we determine beat masses for seven Galactic beat Cepheids for which photometric and spectroscopic data are available. We find an average mass around 4.2+/-0.3 Msolar for these stars, though the actual error limits for each star may be larger mainly because of uncertainties in E(B-V) and the heavy element abundances. (As derived spectroscopically, beat Cepheids are in general metal-poor, with -0.4relation between the derived beat masses and the luminosities again indicates excess mixing that is somewhat larger than that corresponding to the models by Schaller et al.

  17. Heart Rate Extraction from Vowel Speech Signals

    Institute of Scientific and Technical Information of China (English)

    Abdelwadood Mesleh; Dmitriy Skopin; Sergey Baglikov; Anas Quteishat

    2012-01-01

    This paper presents a novel non-contact heart rate extraction method from vowel speech signals.The proposed method is based on modeling the relationship between speech production of vowel speech signals and heart activities for humans where it is observed that the moment of heart beat causes a short increment (evolution) of vowel speech formants.The short-time Fourier transform (STFT) is used to detect the formant maximum peaks so as to accurately estimate the heart rate.Compared with traditional contact pulse oximeter,the average accuracy of the proposed non-contact heart rate extraction method exceeds 95%.The proposed non-contact heart rate extraction method is expected to play an important role in modern medical applications.

  18. Activation and inhibition of the endogenous opioid system in human heart failure.

    OpenAIRE

    Oldroyd, K. G.; Gray, C E; Carter, R.; Harvey, K.; Borland, W; BEASTALL, G; Cobbe, S M

    1995-01-01

    BACKGROUND--In a canine model of congestive heart failure beta endorphin concentrations were high and opioid receptor antagonists exerted beneficial haemodynamic effects. In humans previous studies have suggested that opioid peptides may modify the perception of breathlessness and fatigue in heart failure. METHODS--Plasma concentrations of beta endorphin were measured in patients with acute and chronic heart failure and cardiogenic shock. A subgroup of eight patients with New York Heart Assoc...

  19. Human heart rate variability relation is unchanged during motion sickness

    Science.gov (United States)

    Mullen, T. J.; Berger, R. D.; Oman, C. M.; Cohen, R. J.

    1998-01-01

    In a study of 18 human subjects, we applied a new technique, estimation of the transfer function between instantaneous lung volume (ILV) and instantaneous heart rate (HR), to assess autonomic activity during motion sickness. Two control recordings of ILV and electrocardiogram (ECG) were made prior to the development of motion sickness. During the first, subjects were seated motionless, and during the second they were seated rotating sinusoidally about an earth vertical axis. Subjects then wore prism goggles that reverse the left-right visual field and performed manual tasks until they developed moderate motion sickness. Finally, ILV and ECG were recorded while subjects maintained a relatively constant level of sickness by intermittent eye closure during rotation with the goggles. Based on analyses of ILV to HR transfer functions from the three conditions, we were unable to demonstrate a change in autonomic control of heart rate due to rotation alone or due to motion sickness. These findings do not support the notion that moderate motion sickness is manifested as a generalized autonomic response.

  20. In vivo re-distribution of intra-coronary transplanted stem cells into beating and arrested hearts by magnetic resonance imaging in an acute myocardial infarction swine model%磁共振成像对猪不同心脏状态下经冠状动脉干细胞移植后体内再分布的评价

    Institute of Scientific and Technical Information of China (English)

    陆敏杰; 马宁; 尹刚; 王琳琳; 唐跃; 赵世华; 宋鹏; 蒋世良; 刘琼; 闫朝武; 张岩; 凌坚; 程怀兵

    2010-01-01

    目的 探讨磁共振成像在停跳与不停跳两种心脏状态下,对猪心肌梗死模型经冠状动脉注射骨髓间充质干细胞后全身各主要脏器干细胞早期再分布中的应用价值.方法 用带球囊导管经股动脉选择性插管至雌猪左冠状动脉前降支,在第二对角支的近端将球囊扩张90 min建立急性心肌梗死模型.模型建立后7 d,随机分为4组,分别为不停跳心脏细胞移植组(不停跳组,n=6)与对照组(n=6),停跳心脏细胞移植组(停跳组,n=6)与对照组(n=6).超顺磁氧化铁颗粒(SPIO)标记的干细胞移植3 d后,行磁共振T2*WI示踪检查.取动物心、肝、脾、肺、肾脏的标本,用实时定量聚合酶链反应检测雄性细胞特异性的SRY基因,切片进行普鲁士蓝染色,观察细胞在体内的分布和形态.结果 除肾脏外,心、脾、肝中干细胞移植组T2*值较对照组差异均有统计学意义,但移植组在不同心脏状态下不停跳组与停跳组心肌T2*值差异无统计学意义[(-7.81±2.03)ms比(-6.56±1.72)ms,P>0.05],而不停跳组脾脏及肝脏的T2*值明显低于停跳组[脾脏:(-16.72±2.83)ms比(-22.18±3.98)ms,P<0.01,肝脏:(-2.40±0.44)ms比(-5.32±3.40)ms,P<0.05],在肾脏中两组差异无统计学意义.SRY基因在不停跳组及停跳组的脾脏及肝脏的表达差异有统计学意义,病理学检查见移植细胞呈普鲁士蓝染色阳性.结论 干细胞SPIO标记后,磁共振成像可以作为方便而有效的手段在移植早期活体示踪干细胞,评价其在体内的分布情况.经冠状动脉途径注射骨髓间充质干细胞后,许多细胞流向心脏以外的器官,尤其是脾脏.心脏停跳与不停跳状态下经冠状动脉注射骨髓间充质干细胞对干细胞在心脏的滞留无明显差别.%Objective To analyze the stem cell re-distribution after intra-coronary infusion (ICI)into arrested and beating hearts in a swine myocardial infarction ( MI ) model using magnetic

  1. Clinical study of acupuncture combined with medicine in the treatment of coronary heart disease complicated with ven-tricular premature beat%针药结合治疗冠心病复杂性室性早搏的临床研究

    Institute of Scientific and Technical Information of China (English)

    陈莘桃; 谭小华; 周全; 马俐; 朱文红; 陆青研; 谢月萍; 吴曙粤

    2015-01-01

    Objective To investigate the effect of acupuncture and medicine combined treatment on coronary heart disease (CHD)complicated with complex ventricular premature beat,and thus provide a new way of significant effect,safe,convenient operation and no adverse reactions for the clinical treatment of coronary heart disease complicated with ventricular premature beat. Methods Ninety-nine coronary heart disease patients complicated with complex ventricular premature beat were divided into Wenxin granule plus acupuncture treatment group,Wenxin granule group and acupuncture group. Patients were all deactivated other antiarrhythmic drugs,but still accepted treatment for primary disease drugs. The three groups were treated for 1 month,the clinical symptoms,electrocardiogram and dynamic electrocardiogram,liver and kidney function were observed. Results The treatment effect of Wenxin granule plus acupuncture treatment group was significantly better than that of Wenxin granule group and acupuncture group,the total effective rate was 90. 9% ;the effect of Wenxin granule group was better than that of acupuncture group,and the effective rate was 63. 6% . Before and after treatment,the effect had significant difference in the Wenxin granule plus acupuncture treatment group and Wenxin granule group(P 0. 05). After treatment,the 24 h dynamic electrocardiogram of ventricular premature beat reduce number of Wenxin granule plus acupuncture treatment group was better than that of Wenxin granule group(P 0.05)。治疗后,24 h 动态心电图室性早搏减少数针药组大于稳心组( P <0.05)及针刺组(P <0.01),且稳心组治疗后24 h 动态心电图室性早搏减少数大于针刺组(P <0.01)。结论针药结合治疗冠心病复杂性室性早搏的效果优于单用药物治疗或针刺治疗,单用药物治疗的结果优于单用针刺治疗。

  2. Emergence of dynamical complexity related to human heart rate variability

    Science.gov (United States)

    Chang, Mei-Chu; Peng, C.-K.; Stanley, H. Eugene

    2014-12-01

    We apply the refined composite multiscale entropy (MSE) method to a one-dimensional directed small-world network composed of nodes whose states are binary and whose dynamics obey the majority rule. We find that the resulting fluctuating signal becomes dynamically complex. This dynamical complexity is caused (i) by the presence of both short-range connections and long-range shortcuts and (ii) by how well the system can adapt to the noisy environment. By tuning the adaptability of the environment and the long-range shortcuts we can increase or decrease the dynamical complexity, thereby modeling trends found in the MSE of a healthy human heart rate in different physiological states. When the shortcut and adaptability values increase, the complexity in the system dynamics becomes uncorrelated.

  3. Human Error Assessment and Reduction Technique (HEART) and Human Factor Analysis and Classification System (HFACS)

    Science.gov (United States)

    Alexander, Tiffaney Miller

    2017-01-01

    Research results have shown that more than half of aviation, aerospace and aeronautics mishaps incidents are attributed to human error. As a part of Quality within space exploration ground processing operations, the identification and or classification of underlying contributors and causes of human error must be identified, in order to manage human error.This presentation will provide a framework and methodology using the Human Error Assessment and Reduction Technique (HEART) and Human Factor Analysis and Classification System (HFACS), as an analysis tool to identify contributing factors, their impact on human error events, and predict the Human Error probabilities (HEPs) of future occurrences. This research methodology was applied (retrospectively) to six (6) NASA ground processing operations scenarios and thirty (30) years of Launch Vehicle related mishap data. This modifiable framework can be used and followed by other space and similar complex operations.

  4. Tachycardia | Fast Heart Rate

    Science.gov (United States)

    ... SA) node --- the heart's natural pacemaker - sends out electrical signals faster than usual. The heart rate is fast, but the heart beats properly. Causes of sinus tachycardia A rapid heartbeat may be your body's response to common conditions such as: Fever Anxiety ...

  5. A Simple Dissection Method for the Conduction System of the Human Heart

    Science.gov (United States)

    Yanagawa, Nariaki; Nakajima, Yuji

    2009-01-01

    A simple dissection guide for the conduction system of the human heart is shown. The atrioventricular (AV) node, AV bundle, and right bundle branch were identified in a formaldehyde-fixed human heart. The sinu-atrial (SA) node could not be found, but the region in which SA node was contained was identified using the SA nodal artery. Gross…

  6. A Simple Dissection Method for the Conduction System of the Human Heart

    Science.gov (United States)

    Yanagawa, Nariaki; Nakajima, Yuji

    2009-01-01

    A simple dissection guide for the conduction system of the human heart is shown. The atrioventricular (AV) node, AV bundle, and right bundle branch were identified in a formaldehyde-fixed human heart. The sinu-atrial (SA) node could not be found, but the region in which SA node was contained was identified using the SA nodal artery. Gross…

  7. Rodent heart failure models do not reflect the human circulating microRNA signature in heart failure.

    Science.gov (United States)

    Vegter, Eline L; Ovchinnikova, Ekaterina S; Silljé, Herman H W; Meems, Laura M G; van der Pol, Atze; van der Velde, A Rogier; Berezikov, Eugene; Voors, Adriaan A; de Boer, Rudolf A; van der Meer, Peter

    2017-01-01

    We recently identified a set of plasma microRNAs (miRNAs) that are downregulated in patients with heart failure in comparison with control subjects. To better understand their meaning and function, we sought to validate these circulating miRNAs in 3 different well-established rat and mouse heart failure models, and correlated the miRNAs to parameters of cardiac function. The previously identified let-7i-5p, miR-16-5p, miR-18a-5p, miR-26b-5p, miR-27a-3p, miR-30e-5p, miR-199a-3p, miR-223-3p, miR-423-3p, miR-423-5p and miR-652-3p were measured by means of quantitative real time polymerase chain reaction (qRT-PCR) in plasma samples of 8 homozygous TGR(mREN2)27 (Ren2) transgenic rats and 8 (control) Sprague-Dawley rats, 6 mice with angiotensin II-induced heart failure (AngII) and 6 control mice, and 8 mice with ischemic heart failure and 6 controls. Circulating miRNA levels were compared between the heart failure animals and healthy controls. Ren2 rats, AngII mice and mice with ischemic heart failure showed clear signs of heart failure, exemplified by increased left ventricular and lung weights, elevated end-diastolic left ventricular pressures, increased expression of cardiac stress markers and reduced left ventricular ejection fraction. All miRNAs were detectable in plasma from rats and mice. No significant differences were observed between the circulating miRNAs in heart failure animals when compared to the healthy controls (all P>0.05) and no robust associations with cardiac function could be found. The previous observation that miRNAs circulate in lower levels in human patients with heart failure could not be validated in well-established rat and mouse heart failure models. These results question the translation of data on human circulating miRNA levels to experimental models, and vice versa the validity of experimental miRNA data for human heart failure.

  8. 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.

  9. Genome-wide analysis of alternative splicing during human heart development

    Science.gov (United States)

    Wang, He; Chen, Yanmei; Li, Xinzhong; Chen, Guojun; Zhong, Lintao; Chen, Gangbing; Liao, Yulin; Liao, Wangjun; Bin, Jianping

    2016-01-01

    Alternative splicing (AS) drives determinative changes during mouse heart development. Recent high-throughput technological advancements have facilitated genome-wide AS, while its analysis in human foetal heart transition to the adult stage has not been reported. Here, we present a high-resolution global analysis of AS transitions between human foetal and adult hearts. RNA-sequencing data showed extensive AS transitions occurred between human foetal and adult hearts, and AS events occurred more frequently in protein-coding genes than in long non-coding RNA (lncRNA). A significant difference of AS patterns was found between foetal and adult hearts. The predicted difference in AS events was further confirmed using quantitative reverse transcription-polymerase chain reaction analysis of human heart samples. Functional foetal-specific AS event analysis showed enrichment associated with cell proliferation-related pathways including cell cycle, whereas adult-specific AS events were associated with protein synthesis. Furthermore, 42.6% of foetal-specific AS events showed significant changes in gene expression levels between foetal and adult hearts. Genes exhibiting both foetal-specific AS and differential expression were highly enriched in cell cycle-associated functions. In conclusion, we provided a genome-wide profiling of AS transitions between foetal and adult hearts and proposed that AS transitions and deferential gene expression may play determinative roles in human heart development. PMID:27752099

  10. Genome-wide analysis of alternative splicing during human heart development

    Science.gov (United States)

    Wang, He; Chen, Yanmei; Li, Xinzhong; Chen, Guojun; Zhong, Lintao; Chen, Gangbing; Liao, Yulin; Liao, Wangjun; Bin, Jianping

    2016-10-01

    Alternative splicing (AS) drives determinative changes during mouse heart development. Recent high-throughput technological advancements have facilitated genome-wide AS, while its analysis in human foetal heart transition to the adult stage has not been reported. Here, we present a high-resolution global analysis of AS transitions between human foetal and adult hearts. RNA-sequencing data showed extensive AS transitions occurred between human foetal and adult hearts, and AS events occurred more frequently in protein-coding genes than in long non-coding RNA (lncRNA). A significant difference of AS patterns was found between foetal and adult hearts. The predicted difference in AS events was further confirmed using quantitative reverse transcription-polymerase chain reaction analysis of human heart samples. Functional foetal-specific AS event analysis showed enrichment associated with cell proliferation-related pathways including cell cycle, whereas adult-specific AS events were associated with protein synthesis. Furthermore, 42.6% of foetal-specific AS events showed significant changes in gene expression levels between foetal and adult hearts. Genes exhibiting both foetal-specific AS and differential expression were highly enriched in cell cycle-associated functions. In conclusion, we provided a genome-wide profiling of AS transitions between foetal and adult hearts and proposed that AS transitions and deferential gene expression may play determinative roles in human heart development.

  11. Structure and function relationship of human heart from DENSE MRI

    Science.gov (United States)

    Moghaddam, Abbas N.; Gharib, Morteza

    2007-03-01

    The study here, suggests a macroscopic structure for the Left Ventricle (LV), based on the heart kinematics which is obtained through imaging. The measurement of the heart muscle deformation using the Displacement ENcoding with Stimulated Echoes (DENSE) MRI, which describes the heart kinematics in the Lagrangian frame work, is used to determine the high resolution patterns of true myocardial strain. Subsequently, the tangential Shortening Index (SI) and the thickening of the LV wall are calculated for each data point. Considering the heart as a positive-displacement pump, the contribution of each segment of LV in the heart function, can be determined by the SI and thickening of the wall in the same portion. Hence the SI isosurfaces show the extent and spatial distribution of the heart activity and reveals its macro structure. The structure and function of the heart are, therefore, related which in turn results in a macroscopic model for the LV. In particular, it was observed that the heart functionality is not uniformly distributed in the LV, and the regions with greater effect on the pumping process, form a band which wraps around the heart. These results, which are supported by the established histological evidence, may be considered as a landmark in connecting the structure and function of the heart through imaging. Furthermore, the compatibility of this model with microscopic observations about the fiber direction is investigated. This method may be used for planning as well as post evaluation of the ventriculoplasty.

  12. Bioartificial heart: a human-sized porcine model--the way ahead.

    Directory of Open Access Journals (Sweden)

    Alexander Weymann

    Full Text Available BACKGROUND: A bioartificial heart is a theoretical alternative to transplantation or mechanical left ventricular support. Native hearts decellularized with preserved architecture and vasculature may provide an acellular tissue platform for organ regeneration. We sought to develop a tissue-engineered whole-heart neoscaffold in human-sized porcine hearts. METHODS: We decellularized porcine hearts (n = 10 by coronary perfusion with ionic detergents in a modified Langendorff circuit. We confirmed decellularization by histology, transmission electron microscopy and fluorescence microscopy, quantified residual DNA by spectrophotometry, and evaluated biomechanical stability with ex-vivo left-ventricular pressure/volume studies, all compared to controls. We then mounted the decellularized porcine hearts in a bioreactor and reseeded them with murine neonatal cardiac cells and human umbilical cord derived endothelial cells (HUVEC under simulated physiological conditions. RESULTS: Decellularized hearts lacked intracellular components but retained specific collagen fibers, proteoglycan, elastin and mechanical integrity; quantitative DNA analysis demonstrated a significant reduction of DNA compared to controls (82.6±3.2 ng DNA/mg tissue vs. 473.2±13.4 ng DNA/mg tissue, p<0.05. Recellularized porcine whole-heart neoscaffolds demonstrated re-endothelialization of coronary vasculature and measurable intrinsic myocardial electrical activity at 10 days, with perfused organ culture maintained for up to 3 weeks. CONCLUSIONS: Human-sized decellularized porcine hearts provide a promising tissue-engineering platform that may lead to future clinical strategies in the treatment of heart failure.

  13. 参麦注射液在体外循环心脏不停跳手术中的心肌保护作用%Myocardial protection of Shenmai injection in patients subject to beating-heart surgery

    Institute of Scientific and Technical Information of China (English)

    阳诺; 冼磊; 陈铭伍; 郭建极; 胡松

    2013-01-01

    Objective To evaluate the myocardial protective effects of Shenmai injection in patients udnergoing cardiopul-monary bypass (CPB) surgery on beating-heart.Methods Sixty patients with rheumatic heart disease preparing for mitral valve replacement were randomly divided into two groups:control group (group A,n =30) and experimental group (group B,n =30).The patients in group B were given Shenmai injection 0.6 ml/kg in circuit priming fluids,and those in group A were given equal volume of normal saline.Blood samples were collected before surgery (T1),at 30 min of CPB (T2),at the end of CPB (T3) and operation (T4),24 h after operation (T5),and 72 h after operation (T6) for assessment of lactate dehydrogenase (LDH),CK-MB,cardiac Troponin T (cTnT),superoxide dismutase (SOD) and malondialdehyde (MDA).Results (1) The levels of LDH were significantly lower in group B than in group A at T3 to T6 [(258.55 ± 21.83) U/L vs.(345.12 ± 25.28) U/L,(306.40 ± 26.11) U/L vs.(396.36 ± 22.66) U/L,(335.62 ± 26.72) U/L vs.(415.74 ± 39.56) U/L,(380.00 ± 31.53) U/L vs.(435.45 ±41.39) U/L] (P <0.05).The levels of CK-MB were significantly lower in group B than in group A at T2 to T5 [(33.70 ± 12.60) U/L vs.(42.31 ± 11.03) U/L,(48.91 ± 12.30) U/L vs.(78.81 ±15.03) U/L,(55.82±15.28) U/Lvs.(90.76±20.14) U/L,(73.09 ±24.34) U/Lvs.(109.05 ±24.33) U/L] (P <0.05).The levels of cTnT were significantly lower in group B than in group AatT2 to T6 [(0.89 ± 0.27) U/Lvs.(2.61 ±0.25) U/L,(5.49±1.79) U/Lvs.(11.48±2.41) U/L,(8.31 ±2.44) U/L vs.(18.34 ±3.76) U/L,(17.91 ±3.42) U/L vs.(27.05 ±4.24) U/L,(5.10 ± 1.42) U/L vs.(11.19 ±2.80) U/L] (P<0.05).(2) The levels of SOD were significantly higher in group B than in group A at T2 to T6[(68.69 ±7.26) U/L vs.(55.22 ±7.30) U/L,(54.28 ±7.94) U/L vs.(35.11 ±6.61) U/L,(44.03 ±6.17) U/L vs.(25.41 ±3.98) U/L,(53.93 ±6.76) U/L vs.(41.60 ± 3.79) U/L,(64.27 ± 7.13) U/L vs.(50.02 ± 4.45) U/L] (P < 0.05).The levels of MDA were

  14. 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.

  15. Muscarinic M3 receptor subtype gene expression in the human heart.

    Science.gov (United States)

    Hellgren, I; Mustafa, A; Riazi, M; Suliman, I; Sylvén, C; Adem, A

    2000-01-20

    The heart is an important target organ for cholinergic function. In this study, muscarinic receptor subtype(s) in the human heart were determined using reverse transcription-polymerase chain reaction. Our results demonstrated muscarinic receptor M2 and M3 subtype RNA in left/right atria/ventricles of donor hearts. Receptor autoradiography analysis using selective muscarinic ligands indicated an absence of M1 receptor subtype in the human heart. The level of muscarinic receptor binding in atria was two to three times greater than in ventricles. Our results suggest that muscarinic receptors in the human heart are of the M2 and M3 subtypes. This is the first report of M3 receptors in the human myocardium.

  16. How Is Heart Disease Diagnosed?

    Science.gov (United States)

    ... heart tests are done. If you can't exercise, you may be given medicines to increase your heart rate. When your heart is working hard and beating fast, it needs more blood and oxygen. Plaque-narrowed coronary (heart) arteries can' ...

  17. Protective effects of ulinastatin during non-heart-beating donors lung transplantation%乌司他丁对无心跳兔供肺的保护作用

    Institute of Scientific and Technical Information of China (English)

    倪斌; 马海涛; 谈震东; 祝冒善; 朱逸; 李畅; 宋心雨

    2009-01-01

    Objective To investigate the protective effects of treatment with ulinastatin (UTD during rabbit non-heart-beating donors lung transplantation, and explore the possible mechanism.Methods Thirty rabbits were divided randomly into three groups: group A as control group, group B as UTI flushing group, and group C as UTI preconditioning plus flushing group.In group A donors were exsanguinated to maintain hypotension for 30 rain before intravenous injection of potassium chloride to make heart arrest.After a period of 1 h warm ischemia in situ, topical cooling was executed.Meanwhile, the donor lungs were antegradely flushed through pulmonary arteries with low-potassium-dextron (LPD) solution at 4℃.After flushing in situ, lung-heart blocks were harvested and store at 4 ℃ for another 5 h, then perfused for 90 min in isolated, ventilated, blood-perfused rabbit lung models.Pulmonary venous blood samples were collected for blood gas analysis at 1st, 30th, 60th, and 90th min after initiation of reperfusion.At the same time, PAwP was recorded respectively.Lung samples were obtained at the end of reperfusion.The pulmonary water index (W/D), tissue myeloperoxidase (MPO) activity, tissue malondialdehyde (MDA) content, and mRNA expression of IL-8 and ICAM-1 were measured.Microscopic examination of donor lungs was conducted.In group B, the same procedures were conducted as in group A except for adding UTI (500 000 U/L) to LPD solution.In group C, except that a bolus of UTI (50 000 U/kg) was given to donors intravenously during hypotension, the same procedures were conducted as in group B.Results (1) In all three groups, there were same tendencies of gradually decreasing of PO2 levels; and as compared with groups B and C, PO2 levels in group A were significantly reduced.Similar results could be observed in PAwP values, but the tendency was increasing.(2) The level of W/D, MPO activity, MDA content, and the mRNA expression of IL-8 and ICAM-1 in groups B and C were decreased as

  18. Characteristic parameters of electromagnetic signals from a human heart system

    Institute of Scientific and Technical Information of China (English)

    Liu Xin-Yuan; Pei Liu-Qing; Wang Yin; Zhang Su-Ming; Gao Hong-Lei; Dai Yuan-Dong

    2011-01-01

    The electromagnetic field of a human heart system is a bioelectromagnetic field. Electrocardiography (ECG)and magnetocardiography (MCG)are both carriers of electromagnetic information about the cardiac system, and they are nonstationary signals. In this study, ECG and MCG data from healthy subjects are acquired;the MCG data are captured using a high-T, radio frequency superconducting quantum interference device (HTc rf SQUIDs)and the QRS complexes in these data are analysed by the evolutionary spectrum analysis method. The results show that the quality factor Q and the central frequency fz of the QRS complex evolutionary spectrum are the characteristic parameters (CHPs)of ECG and MCG in the time-frequency domain. The confidence intervals of the mean values of the CHPs are estimated by the Student t distribution method in mathematical statistics. We believe that there are threshold ranges of the mean values of Q and fz for healthy subjects. We have postulated the following criterion:if the mean values of CHPs are in the proper ranges, the cardiac system is in a normal condition and it possesses the capability of homeostasis. In contrast, if the mean values of the CHPs do not lie in the proper ranges, the homeostasis of the cardiac system is lacking and some cardiac disease may follow. The results and procedure of MCG CHPs in the study afford a technological route for the application of HTc rf SQUIDs in cardiology.

  19. Analysis of necroptotic proteins in failing human hearts.

    Science.gov (United States)

    Szobi, Adrián; Gonçalvesová, Eva; Varga, Zoltán V; Leszek, Przemyslaw; Kuśmierczyk, Mariusz; Hulman, Michal; Kyselovič, Ján; Ferdinandy, Péter; Adameová, Adriana

    2017-04-28

    Cell loss and subsequent deterioration of contractile function are hallmarks of chronic heart failure (HF). While apoptosis has been investigated as a participant in the progression of HF, it is unlikely that it accounts for the total amount of non-functional tissue. In addition, there is evidence for the presence of necrotic cardiomyocytes in HF. Therefore, the objective of this study was to investigate the necroptotic proteins regulating necroptosis, a form of programmed necrosis, and thereby assess its potential role in human end-stage HF. Left ventricular samples of healthy controls (C) and patients with end-stage HF due to myocardial infarction (CAD) or dilated cardiomyopathy (DCM) were studied. Immunoblotting for necroptotic and apoptotic markers was performed. Triton X-114 fractionated samples were analyzed to study differences in subcellular localization. Elevated expression of RIP1 (receptor-interacting protein), pSer(227)-RIP3 and its total levels were observed in HF groups compared to controls. On the other hand, caspase-8 expression, a proapoptotic protease negatively regulating necroptosis, was downregulated suggesting activation of necroptosis signaling. Total mixed-lineage kinase domain-like protein (MLKL) expression did not differ among the groups; however, active cytotoxic forms of MLKL were present in all HF samples while they were expressed at almost undetectable levels in controls. Interestingly, pThr(357)-MLKL unlike pSer(358)-MLKL, was higher in DCM than CAD. In HF, the subcellular localization of both RIP3 and pThr(357)-MLKL was consistent with activation of necroptosis signaling. Expression of main apoptotic markers has not indicated importance of apoptosis. This is the first evidence showing that human HF of CAD or DCM etiology is positive for markers of necroptosis which may be involved in the development of HF.

  20. Cyclooxygenase products sensitize muscle mechanoreceptors in humans with heart failure.

    Science.gov (United States)

    Middlekauff, Holly R; Chiu, Josephine; Hamilton, Michele A; Fonarow, Gregg C; Maclellan, W Robb; Hage, Antoine; Moriguchi, Jaime; Patel, Jignesh

    2008-04-01

    Prior work in animals and humans suggests that muscle mechanoreceptor control of sympathetic activation [muscle sympathetic nerve activity (MSNA)] during exercise in heart failure (HF) patients is heightened compared with that of healthy humans and that muscle mechanoreceptors are sensitized by metabolic by-products. We sought to determine whether cyclooxygenase products and/or endogenous adenosine, two metabolites of ischemic exercise, sensitize muscle mechanoreceptors during rhythmic handgrip (RHG) exercise in HF patients. Indomethacin, which inhibits the production of prostaglandins, and saline control were infused in 12 HF patients. In a different protocol, aminophylline, which inhibits adenosine receptors, and saline control were infused in 12 different HF patients. MSNA was recorded (microneurography). During exercise following saline, MSNA increased in the first minute of exercise, consistent with baseline heightened mechanoreceptor sensitivity. MSNA continued to increase during 3 min of RHG, indicative that muscle mechanoreceptors are sensitized by ischemia metabolites. Indomethacin, but not aminophylline, markedly attenuated the increase in MSNA during the entire 3 min of low-level rhythmic exercise, consistent with the sensitization of muscle mechanoreceptors by cyclooxygenase products. Interestingly, even the early increase in MSNA was abolished by indomethacin infusion, indicative of the very early generation of cyclooxygenase products after the onset of exercise in HF patients. In conclusion, muscle mechanoreceptors mediate the increase in MSNA during low-level RHG exercise in HF. Cyclooxygenase products, but not endogenous adenosine, play a central role in muscle mechanoreceptor sensitization. Finally, muscle mechanoreceptors in patients with HF have heightened basal sensitivity to mechanical stimuli, which also appears to be mediated by the early generation of cyclooxygenase products, resulting in exaggerated early increases in MSNA.

  1. Cardiac protein kinases: the cardiomyocyte kinome and differential kinase expression in human failing hearts

    OpenAIRE

    Fuller, Stephen J.; Osborne, Sally A.; Leonard, Sam J.; Hardyman, Michelle A.; Vaniotis, George; Allen, Bruce G.; Sugden, Peter H.; Clerk, Angela

    2015-01-01

    Aims. Protein kinases are potential therapeutic targets for heart failure, but most studies of cardiac protein kinases derive from other systems, an approach that fails to account for specific kinases expressed in the heart and the contractile cardiomyocytes. We aimed to define the cardiomyocyte kinome (i.e. the protein kinases expressed in cardiomyocytes) and identify kinases with altered expression in human failing hearts. Methods and Results. Expression profiling (Affymetrix microarrays) d...

  2. Resonance of about-weekly human heart rate rhythm with solar activity change.

    Science.gov (United States)

    Cornelissen, G; Halberg, F; Wendt, H W; Bingham, C; Sothern, R B; Haus, E; Kleitman, E; Kleitman, N; Revilla, M A; Revilla, M; Breus, T K; Pimenov, K; Grigoriev, A E; Mitish, M D; Yatsyk, G V; Syutkina, E V

    1996-12-01

    In several human adults, certain solar activity rhythms may influence an about 7-day rhythm in heart rate. When no about-weekly feature was found in the rate of change in sunspot area, a measure of solar activity, the double amplitude of a circadian heart rate rhythm, approximated by the fit of a 7-day cosine curve, was lower, as was heart rate corresponds to about-weekly features in solar activity and/or relates to a sunspot cycle.

  3. Human heart conjugate cooling simulation: unsteady thermo-fluid-stress analysis.

    Science.gov (United States)

    Abdoli, Abas; Dulikravich, George S; Bajaj, Chandrajit; Stowe, David F; Jahania, M Salik

    2014-11-01

    The main objective of this work was to demonstrate computationally that realistic human hearts can be cooled much faster by performing conjugate heat transfer consisting of pumping a cold liquid through the cardiac chambers and major veins while keeping the heart submerged in cold gelatin filling a cooling container. The human heart geometry used for simulations was obtained from three-dimensional, high resolution CT-angio scans. Two fluid flow domains for the right (pulmonic) and left (systemic) heart circulations, and two solid domains for the heart tissue and gelatin solution were defined for multi-domain numerical simulation. Detailed unsteady temperature fields within the heart tissue were calculated during the conjugate cooling process. A linear thermoelasticity analysis was performed to assess the stresses applied on the heart due to the coolant fluid shear and normal forces and to examine the thermal stress caused by temperature variation inside the heart. It was demonstrated that a conjugate cooling effort with coolant temperature at +4°C is capable of reducing the average heart temperature from +37°C to +8°C in 25 minutes for cases in which the coolant was steadily pumped only through major heart inlet veins and cavities. Copyright © 2014 John Wiley & Sons, Ltd.

  4. Response of cat inferior colliculus neurons to binaural beat stimuli: possible mechanisms for sound localization.

    Science.gov (United States)

    Kuwada, S; Yin, T C; Wickesberg, R E

    1979-11-02

    The interaural phase sensitivity of neurons was studied through the use of binaural beat stimuli. The response of most cells was phase-locked to the beat frequency, which provides a possible neural correlate to the human sensation of binaural beats. In addition, this stimulus allowed the direction and rate of interaural phase change to be varied. Some neurons in our sample responded selectively to manipulations of these two variables, which suggests a sensitivity to direction or speed of movement.

  5. Blood pressure and heart rate variability analysis of orthostatic challenge in normal human pregnancies.

    Science.gov (United States)

    Heiskanen, Nonna; Saarelainen, Heli; Valtonen, Pirjo; Lyyra-Laitinen, Tiina; Laitinen, Tomi; Vanninen, Esko; Heinonen, Seppo

    2008-11-01

    The aim of the present study was to evaluate pregnancy-related changes in autonomic regulatory functions in healthy subjects. We studied cardiovascular autonomic responses to head-up tilt (HUT) in 28 pregnant women during the third trimester of pregnancy and 3 months after parturition. The maternal ECG and non-invasive beat-to-beat blood pressure were recorded in the horizontal position (left-lateral position) and during HUT in the upright position. Stroke volume was assessed from blood pressure signal by using the arterial pulse contour method. Heart rate variability (HRV) was analysed in frequency domain, and baroreflex sensitivity by the cross-spectral and the sequence methods. In the horizontal position, all frequency components of HRV were lower during pregnancy than 3 months after parturition (P < 0.01 to <0.001), while pregnancy had no influence on normalized low frequency and high frequency powers. During pregnancy haemodynamics was well balanced with only minor changes in response to postural change while haemodynamic responses to HUT were more remarkable after parturition. In pregnant women HRV and especially its very low frequency component increased in response to HUT, whereas at 3 months after parturition the direction of these changes was opposite. Parasympathetic deactivation towards term is likely to contribute to increased heart rate and cardiac output at rest, whereas restored sympathetic modulation with modest responses may contribute stable peripheral resistance and sufficient placental blood supply under stimulated conditions. It is important to understand cardiovascular autonomic nervous system and haemodynamic control in normal pregnancy before being able to judge whether they are dysregulated in complicated pregnancies.

  6. The Visible Heart® project and free-access website 'Atlas of Human Cardiac Anatomy'.

    Science.gov (United States)

    Iaizzo, Paul A

    2016-12-01

    Pre- and post-evaluations of implantable cardiac devices require innovative and critical testing in all phases of the design process. The Visible Heart(®) Project was successfully launched in 1997 and 3 years later the Atlas of Human Cardiac Anatomy website was online. The Visible Heart(®) methodologies and Atlas website can be used to better understand human cardiac anatomy, disease states and/or to improve cardiac device design throughout the development process. To date, Visible(®) Heart methodologies have been used to reanimate 75 human hearts, all considered non-viable for transplantation. The Atlas is a unique free-access website featuring novel images of functional and fixed human cardiac anatomies from >400 human heart specimens. Furthermore, this website includes education tutorials on anatomy, physiology, congenital heart disease and various imaging modalities. For instance, the Device Tutorial provides examples of commonly deployed devices that were present at the time of in vitro reanimation or were subsequently delivered, including: leads, catheters, valves, annuloplasty rings, leadless pacemakers and stents. Another section of the website displays 3D models of vasculature, blood volumes, and/or tissue volumes reconstructed from computed tomography (CT) and magnetic resonance images (MRI) of various heart specimens. A new section allows the user to interact with various heart models. Visible Heart(®) methodologies have enabled our laboratory to reanimate 75 human hearts and visualize functional cardiac anatomies and device/tissue interfaces. The website freely shares all images, video clips and CT/MRI DICOM files in honour of the generous gifts received from donors and their families. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2016. For Permissions, please email: journals.permissions@oup.com.

  7. Electrical admittance for filling of the heart during lower body negative pressure in humans

    DEFF Research Database (Denmark)

    Cai, Yujia; Holm, S; Jenstrup, M;

    2000-01-01

    lower body negative pressure (LBNP) in humans. Changes in Thorax(ICW) were compared with positron emission tomography-determined C(15)O-labeled erythrocytes over the heart. During -40 mmHg LBNP, the blood volume of the heart decreased by 21 +/- 3% as the erythrocyte volume was reduced by 20 +/- 2...

  8. Evidence for differential sympathetic and parasympathetic reinnervation after heart transplantation in humans

    NARCIS (Netherlands)

    Tio, RA; Reyners, AKL; Van Veldhuisen, DJ; Van den Berg, MP; Brouwer, RMHJ; Haaksma, J; Smit, AJ; Crijns, HJGM

    1997-01-01

    During heart transplantation (HTX) all neural connections are severed, Ln humans, signs of autonomic reinnervation have been found, in this study non-invasive tests were used to compare signs of sympathetic and parasympathetic reinnervation. Non-invasive autonomic function tests and heart rate varia

  9. Prospective isolation of human embryonic stem cell-derived cardiovascular progenitors that integrate into human fetal heart tissue.

    Science.gov (United States)

    Ardehali, Reza; Ali, Shah R; Inlay, Matthew A; Abilez, Oscar J; Chen, Michael Q; Blauwkamp, Timothy A; Yazawa, Masayuki; Gong, Yongquan; Nusse, Roeland; Drukker, Micha; Weissman, Irving L

    2013-02-26

    A goal of regenerative medicine is to identify cardiovascular progenitors from human ES cells (hESCs) that can functionally integrate into the human heart. Previous studies to evaluate the developmental potential of candidate hESC-derived progenitors have delivered these cells into murine and porcine cardiac tissue, with inconclusive evidence regarding the capacity of these human cells to physiologically engraft in xenotransplantation assays. Further, the potential of hESC-derived cardiovascular lineage cells to functionally couple to human myocardium remains untested and unknown. Here, we have prospectively identified a population of hESC-derived ROR2(+)/CD13(+)/KDR(+)/PDGFRα(+) cells that give rise to cardiomyocytes, endothelial cells, and vascular smooth muscle cells in vitro at a clonal level. We observed rare clusters of ROR2(+) cells and diffuse expression of KDR and PDGFRα in first-trimester human fetal hearts. We then developed an in vivo transplantation model by transplanting second-trimester human fetal heart tissues s.c. into the ear pinna of a SCID mouse. ROR2(+)/CD13(+)/KDR(+)/PDGFRα(+) cells were delivered into these functioning fetal heart tissues: in contrast to traditional murine heart models for cell transplantation, we show structural and functional integration of hESC-derived cardiovascular progenitors into human heart.

  10. Ischemic heart disease induces upregulation of endothelin receptor mRNA in human coronary arteries

    DEFF Research Database (Denmark)

    Wackenfors, Angelica; Emilson, Malin; Ingemansson, Richard;

    2004-01-01

    and controls using real-time polymerase chain reaction (real-time PCR). In addition, the suitability of organ culture as a model mimicking endothelin receptor changes in cardiovascular disease was evaluated by in vitro pharmacology and real-time PCR. Endothelin ETA and ETB receptor mRNA levels were......Endothelin has been implicated in the pathogenesis of ischemic heart disease and congestive heart failure. The aims were to quantify endothelin type A (ETA) and type B (ETB) receptor mRNA levels in human coronary arteries from patients with ischemic heart disease, congestive heart failure...

  11. What Are Coronary Heart Disease Risk Factors?

    Science.gov (United States)

    ... t even on Jennifer's radar. And when this television news reporter suffered a heart attack at age ... part of the National Institutes of Health (NIH). Sleep Apnea Research: The HeartBeat Study 06/07/2012 ...

  12. Value of evaluating diastolic function with the single-beat E/(e’ × s) obtained by dual doppler echocardiograph in coronary heart disease patients with preserved left ventricular systolic function

    Institute of Scientific and Technical Information of China (English)

    汪晶晶

    2014-01-01

    Objective To assess the value of E/(e’×s)in estimating left ventricular diastolic dysfunction in patients with coronary heart disease by dual Doppler echocardiograph.Methods Seventy-seven consecutive coronary heart disease patients with preserved systolic function underwent echocardiographic study were included.The E,e’and s were obtained by the dual Doppler echocardio-

  13. Cardiac spheroids as promising in vitro models to study the human heart microenvironment

    DEFF Research Database (Denmark)

    Polonchuk, Liudmila; Chabria, Mamta; Badi, Laura

    2017-01-01

    and fibroblasts at ratios approximating those present in vivo. The cellular organisation, extracellular matrix and microvascular network mimic human heart tissue. These spheroids have been employed to investigate the dose-limiting cardiotoxicity of the common anti-cancer drug doxorubicin. Viability......, biochemistry and pharmacology in vitro, offering a promising alternative to animals and standard cell cultures with regard to mechanistic insights and prediction of toxic effects in human heart tissue....

  14. Characteristic of c-Kit+ progenitor cells in explanted human hearts

    OpenAIRE

    Matuszczak, Sybilla; Czapla, Justyna; Jarosz-Biej, Magdalena; Wiśniewska, Ewa; Cichoń, Tomasz; Smolarczyk, Ryszard; Kobusińska, Magdalena; Gajda, Karolina; Wilczek, Piotr; Śliwka, Joanna; Zembala, Michał; Zembala, Marian; Szala, Stanisław

    2014-01-01

    According to literature data, self-renewing, multipotent, and clonogenic cardiac c-Kit+ progenitor cells occur within human myocardium. The aim of this study was to isolate and characterize c-Kit+ progenitor cells from explanted human hearts. Experimental material was obtained from 19 adult and 7 pediatric patients. Successful isolation and culture was achieved for 95 samples (84.1 %) derived from five different regions of the heart: right and left ventricles, atrium, intraventricular septum,...

  15. Myocardial bridges of the coronary arteries in the human fetal heart.

    Science.gov (United States)

    Cakmak, Yusuf Ozgür; Cavdar, Safiye; Yalin, Aymelek; Yener, Nuran; Ozdogmus, Omer

    2010-09-01

    During the last century, many investigators reported on myocardial bridges in the adult human heart. In the present study, 39 human fetal hearts (the mean gestastional age was 30 weeks) were studied for myocardial bridging, and the results were correlated with adult data. Among the 39 (27 male and 12 female) fetal hearts studied, 26 bridges were observed on 18 fetal hearts (46.2%). Ten of the bridges had one myocardial bridge, whereas double myocardial bridges were observed in eight fetal hearts. The most frequent myocardial bridges were observed on the left anterior descending artery (LAD), which had 13 bridges (50%). Eight (30.7%) myocardial bridges were on the diagonal artery, and on the posterior descending artery there were five (19.3%). Myocardial bridges were not observed on the circumflex artery. The data presented in this study may provide potentially useful information for the preoperative evaluation of the newborn and may have a clinical implication for sudden fetal death.

  16. Noninvasive continuous beat-to-beat radial artery pressure via TL-200 applanation tonometry.

    Science.gov (United States)

    Dueck, Ron; Goedje, Oliver; Clopton, Paul

    2012-04-01

    The Tensys TL-200(®) noninvasive beat-to-beat blood pressure (BP) monitor displays continuous radial artery waveform as well as systolic, mean and diastolic BP from a pressure sensor directly over the radial artery at the wrist. It locates the site of maximal radial pulse signal, determines mean BP from maximal pulse waveform amplitude at optimal artery compression and then derives systolic and diastolic BP. We performed a cross-sectional study of TL-200 BP comparisons with contralateral invasive radial artery (A-Line) BP values in 19 subjects during an average 2.5 h of general anesthesia for a wide range of surgical procedures. Two hundred and fifty random sample pairs/patient resulted in 4,747 systolic, mean and diastolic BP pairs for analysis. A-Line BP ranged from 29 mm Hg diastolic to 211 mm Hg systolic, and heart rate varied between 38 and 210 beats/min. Bland-Altman analysis showed an average 2.3 mm Hg TL-200 versus A-Line systolic BP bias and limits of agreement (1.96 SD) were ± 15.3 mm Hg. Mean BP showed a 2.3 mm Hg TL-200 bias and ± 11.7 mm Hg limits of agreement, while diastolic BP showed a 1.7 mm Hg bias and ± 12.3 mm Hg limits of agreement. Coefficients of determination for TL-200 and A-Line BP regression were r² = 0.86 for systolic, r² = 0.86 for mean, and r² = 80 for diastolic BP, respectively, with no apparent change in correlation at low or high BP. Bland-Altman analysis suggested satisfactory agreement between TL-200 noninvasive beat-to-beat BP and invasive A-Line BP. Paired TL-200/A-Line BP comparisons showed a high coefficient of determination.

  17. Stochastic Alternating Dynamics for Synchronous EAD-Like Beating Rhythms in Cultured Cardiac Myocytes

    Institute of Scientific and Technical Information of China (English)

    ZHANG Ning; ZHANG Hui-Min; LIU Zhi-Qiang; DING Xue-Li; YANG Ming-Hao; GU Hua-Guang; REN Wei

    2009-01-01

    Dissolved cardiac myocytes can couple together and generate synchronous beatings in culture. We observed a synchronized early after-depolarization(EAD)-like rhythm in cultured cardiac myocytes and reproduced the experimental observation in a network mathematical model whose dynamics are close to a Hopf bifurcation. The mechanism for this EAD-like rhythm is attributed to noised-induced stochastic alternatings between the focus and the limit cycle. These results provide novel understandings for pathological heart rhythms like the early immature beatings.

  18. Minimal changes in heart rate of incubating American Oystercatchers (Haematopus palliatus) in response to human activity

    Science.gov (United States)

    Borneman, Tracy E.; Rose, Eli T.; Simons, Theodore R.

    2014-01-01

    An organism's heart rate is commonly used as an indicator of physiological stress due to environmental stimuli. We used heart rate to monitor the physiological response of American Oystercatchers (Haematopus palliatus) to human activity in their nesting environment. We placed artificial eggs with embedded microphones in 42 oystercatcher nests to record the heart rate of incubating oystercatchers continuously for up to 27 days. We used continuous video and audio recordings collected simultaneously at the nests to relate physiological response of birds (heart rate) to various types of human activity. We observed military and civilian aircraft, off-road vehicles, and pedestrians around nests. With the exception of high-speed, low-altitude military overflights, we found little evidence that oystercatcher heart rates were influenced by most types of human activity. The low-altitude flights were the only human activity to significantly increase average heart rates of incubating oystercatchers (12% above baseline). Although statistically significant, we do not consider the increase in heart rate during high-speed, low-altitude military overflights to be of biological significance. This noninvasive technique may be appropriate for other studies of stress in nesting birds.

  19. Demonstrations of Beats as Moving Interference Patterns.

    Science.gov (United States)

    Stein, T. S.; Dishman, L. G.

    1982-01-01

    Describes a ripple tank demonstration that displays interference patterns responsible for producing beats and provides photographs of computer simulations of various beat interference patterns. Includes programs for the computer simulation and equations of constructive interference paths in beat interference patterns. (Author/SK)

  20. Study of the relationship between the aerobic capacity (VO2 max) and the rating of perceived exertion based on the measurement of heart beat in the metal industries Esfahan

    Science.gov (United States)

    Habibi, Ehsanollah; Dehghan, Habibollah; Moghiseh, Mohammad; Hasanzadeh, Akbar

    2014-01-01

    Background and Objective: To establish a balance between work (physical exercise) and human beings, the aerobic capacity (VO2 max) could be used as a measure. Additionally, the subjective and physiological assessment could be applied as one of the methods for assessing physical exercise. The most commonly used tools for the assessment of fatigue during physical exercise include the Borg scale Rating of perceived Exertion (RPE) in relation to subjective symptoms and heart rate (HR) in relation to physiological symptoms. The study is aimed to investigate the relationship between the aerobic capacity and the RPE based on the measurement of heat rate (HR) of workers from the Metal Industries of Isfahan. Materials and Methods: The subjects were 200 male workers from metal components manufacturers in Isfahan selected by using random sampling based on statistic method. The subjects were examined by using ergometer in accordance with A strand 6 minutes cycle test protocol. Furthermore, the subjects were asked to rate their status based on the Borg rating scale at the end of each minute. Additionally, their heat rates were monitored and recorded automatically at the end of each minutes. Results: Statistical analysis showed that there was a significant relationship between the RPE and the aerobic capacity (VO2 max) (r = –0.904, P VO2 max (r = 0.991, P VO2 max and HR. Conclusions: The results indicated that there was a strong relationship between the RPE and VO2 max, as well as a greater correlation between HR and VO2 max. Therefore, the HR could be used as a Prediction measure to estimate VO2 max. PMID:25077148

  1. Human interstitial cellular model in therapeutics of heart valve calcification.

    Science.gov (United States)

    He, Caimei; Tang, Hai; Mei, Zijian; Li, Nichujie; Zeng, Zhi; Darko, Kwame Oteng; Yin, Yulong; Hu, Chien-An Andy; Yang, Xiaoping

    2017-05-23

    Calcific aortic valve disease is a common, severe heart condition that is currently with no proven, effective drug treatment and requires a surgical valve replacement or an entire heart explanation. Thus, developing novel, targeted therapeutic approaches becomes a major goal for cardiovascular disease research. To achieve this goal, isolated heart valve interstitial cells could be an advanced model to explore molecular mechanisms and measure drug efficacy. Based on this progress, molecular mechanisms that harbor components of  inflammation and fibrosis coupled with proteins, for example, BMP-2, TLRs, RANKL, Osteoprotegerin, have been proposed. Small molecules or antibodies targeting these proteins have shown promising efficacy for either reversing or slowing down calcification development in vitro. In this review, we summarize these potential therapeutics with some highlights of interstitial cellular models.

  2. Total lymphatic irradiation and bone marrow in human heart transplantation

    Energy Technology Data Exchange (ETDEWEB)

    Kahn, D.R.; Hong, R.; Greenberg, A.J.; Gilbert, E.F.; Dacumos, G.C.; Dufek, J.H.

    1984-08-01

    Six patients, aged 36 to 59 years, had heart transplants for terminal myocardial disease using total lymphatic irradiation (TLI) and donor bone marrow in addition to conventional therapy. All patients were poor candidates for transplantation because of marked pulmonary hypertension, unacceptable tissue matching, or age. Two patients are living and well more than four years after the transplants. Two patients died of infection at six and seven weeks with normal hearts. One patient, whose preoperative pulmonary hypertension was too great for an orthotopic heart transplant, died at 10 days after such a procedure. The other patient died of chronic rejection seven months postoperatively. Donor-specific tolerance developed in 2 patients. TLI and donor bone marrow can produce specific tolerance to donor antigens and allow easy control of rejection, but infection is still a major problem. We describe a new technique of administering TLI with early reduction of prednisone that may help this problem.

  3. Intact Imaging of Human Heart Structure Using X-ray Phase-Contrast Tomography.

    Science.gov (United States)

    Kaneko, Yukihiro; Shinohara, Gen; Hoshino, Masato; Morishita, Hiroyuki; Morita, Kiyozo; Oshima, Yoshihiro; Takahashi, Masashi; Yagi, Naoto; Okita, Yutaka; Tsukube, Takuro

    2017-02-01

    Structural examination of human heart specimens at the microscopic level is a prerequisite for understanding congenital heart diseases. It is desirable not to destroy or alter the properties of such specimens because of their scarcity. However, many of the currently available imaging techniques either destroy the specimen through sectioning or alter the chemical and mechanical properties of the specimen through staining and contrast agent injection. As a result, subsequent studies may not be possible. X-ray phase-contrast tomography is an imaging modality for biological soft tissues that does not destroy or alter the properties of the specimen. The feasibility of X-ray phase-contrast tomography for the structural examination of heart specimens was tested using infantile and fetal heart specimens without congenital diseases. X-ray phase-contrast tomography was carried out at the SPring-8 synchrotron radiation facility using the Talbot grating interferometer at the bending magnet beamline BL20B2 to visualize the structure of five non-pretreated whole heart specimens obtained by autopsy. High-resolution, three-dimensional images were obtained for all specimens. The images clearly showed the myocardial structure, coronary vessels, and conduction bundle. X-ray phase-contrast tomography allows high-resolution, three-dimensional imaging of human heart specimens. Intact imaging using X-ray phase-contrast tomography can contribute to further structural investigation of heart specimens with congenital heart diseases.

  4. Right ventricular arrhythmogenesis in failing human heart: the role of conduction and repolarization remodeling

    Science.gov (United States)

    Lou, Qing; Janks, Deborah L.; Holzem, Katherine M.; Lang, Di; Onal, Birce; Ambrosi, Christina M.; Fedorov, Vadim V.; Wang, I-Wen

    2012-01-01

    Increased dispersion of repolarization has been suggested to underlie increased arrhythmogenesis in human heart failure (HF). However, no detailed repolarization mapping data were available to support the presence of increased dispersion of repolarization in failing human heart. In the present study, we aimed to determine the existence of enhanced repolarization dispersion in the right ventricular (RV) endocardium from failing human heart and examine its association with arrhythmia inducibility. RV free wall preparations were dissected from five failing and five nonfailing human hearts, cannulated and coronary perfused. RV endocardium was optically mapped from an ∼6.3 × 6.3 cm2 field of view. Action potential duration (APD), dispersion of APD, and conduction velocity (CV) were quantified for basic cycle lengths (BCL) ranging from 2,000 ms to the functional refractory period. We found that RV APD was significantly prolonged within the failing group compared with the nonfailing group (560 ± 44 vs. 448 ± 39 ms, at BCL = 2,000 ms, P < 0.05). Dispersion of APD was increased in three failing hearts (161 ± 5 vs. 86 ± 19 ms, at BCL = 2,000 ms). APD alternans were induced by rapid pacing in these same three failing hearts. CV was significantly reduced in the failing group compared with the nonfailing group (81 ± 11 vs. 98 ± 8 cm/s, at BCL = 2,000 ms). Arrhythmias could be induced in two failing hearts exhibiting an abnormally steep CV restitution and increased dispersion of repolarization due to APD alternans. Dispersion of repolarization is enhanced across the RV endocardium in the failing human heart. This dispersion, together with APD alternans and abnormal CV restitution, could be responsible for the arrhythmia susceptibility in human HF. PMID:23042951

  5. Muscle metaboreflex and autonomic regulation of heart rate in humans

    DEFF Research Database (Denmark)

    Fisher, James P; Adlan, Ahmed M; Shantsila, Alena

    2013-01-01

    We elucidated the autonomic mechanisms whereby heart rate (HR) is regulated by the muscle metaboreflex. Eight male participants (22 ± 3 years) performed three exercise protocols: (1) enhanced metaboreflex activation with partial flow restriction (bi-lateral thigh cuff inflation) during leg cycling...

  6. Encounters with the Human Heart: An Interview with John Stone.

    Science.gov (United States)

    Flynn, Dale Bachman

    1995-01-01

    Interviews Dale Bachman Flynn, professor of cardiology and dean of admissions and student affairs at Emory University School of Medicine, about his "In the Country of Hearts," a collection of stories about his medical practice. Discusses Flynn's personal life; his life-long practice of writing; and his interest in the intersections among medicine,…

  7. Variability of the human heart rate as a diagnostic instrument obtained by mean of a wireless monitor

    Science.gov (United States)

    Barajas Mauricio, Sánchez; Hernández González, Martha Alicia; Figueroa Vega, Nicte; Malacara Hernández, Juan Manuel; Fraga Teodoro, Córdova

    2014-11-01

    Introduction: Heart rate variability (HRV) is the cyclic measurement of RR intervals between normal beats. Aim: To determine the VFC via a wireless Polar monitor. Material and methods: 100 symptomatic menopausal women were studied for measurements of HRV were I post a Polar RS400 Watch four hrs. Results: Obtained through the fast Fourier transform, the frequency domain HRV low frequency (LF) 0.04-0.15 Hz, high frequency (HF) 0.15-0.4Hz and the ratio LF / HF. Conclusion: obtaining HRV is important for cardiovascular autonomic assessment in menopausal women.

  8. Proteomic analysis of membrane microdomains derived from both failing and non-failing human hearts.

    Science.gov (United States)

    Banfi, Cristina; Brioschi, Maura; Wait, Robin; Begum, Shajna; Gianazza, Elisabetta; Fratto, Pasquale; Polvani, Gianluca; Vitali, Ettore; Parolari, Alessandro; Mussoni, Luciana; Tremoli, Elena

    2006-03-01

    Eukaryotic cells plasma membranes are organized into microdomains of specialized function such as lipid rafts and caveolae, with a specific lipid composition highly enriched in cholesterol and glycosphingolipids. In addition to their role in regulating signal transduction, multiple functions have been proposed, such as anchorage of receptors, trafficking of cholesterol, and regulation of permeability. However, an extensive understanding of their protein composition in human heart, both in failing and non-failing conditions, is not yet available. Membrane microdomains were isolated from left ventricular tissue of both failing (n = 15) and non-failing (n = 15) human hearts. Protein composition and differential protein expression was explored by comparing series of 2-D maps and subsequent identification by LC-MS/MS analysis. Data indicated that heart membrane microdomains are enriched in chaperones, cytoskeletal-associated proteins, enzymes and protein involved in signal transduction pathway. In addition, differential protein expression profile revealed that 30 proteins were specifically up- or down-regulated in human heart failure membrane microdomains. This study resulted in the identification of human heart membrane microdomain protein composition, which was not previously available. Moreover, it allowed the identification of multiple proteins whose expression is altered in heart failure, thus opening new perspectives to determine which role they may play in this disease.

  9. Proteomic analysis of effluents from perfused human heart for transplantation: identification of potential biomarkers for ischemic heart damage

    Directory of Open Access Journals (Sweden)

    Li Hong

    2012-03-01

    Full Text Available Abstract Background Biomarkers released from the heart at early stage of ischemia are very important to diagnosis of ischemic heart disease and salvage myocytes from death. Known specific markers for blood tests including CK-MB, cardiac troponin T (cTnT and cardiac troponin I (cTnI are released after the onset of significant necrosis instead of early ischemia. Thus, they are not good biomarkers to diagnose myocardial injury before necrosis happens. Therefore, in this study, we performed proteomic analysis on effluents from perfused human hearts of donors at different ischemic time. Results After global ischemia for 0 min, 30 min and 60 min at 4°C, effluents from five perfused hearts were analyzed respectively, by High performance liquid chromatography-Chip-Mass spectrometry (HPLC-Chip-MS system. Total 196 highly reliable proteins were identified. 107 proteins were identified at the beginning of ischemia, 174 and 175 proteins at ischemic 30 min and ischemic 60 min, respectively. With the exception of cardiac troponin I and T, all known biomarkers for myocardial ischemia were detected in our study. However, there were four glycolytic enzymes and two targets of matrix metalloproteinase released significantly from the heart when ischemic time was increasing. These proteins were L-lactate dehydrogenase B(LDHB, glyceraldehyde-3-phosphate dehydrogenase, glucose-6-phosphate isomerase (GPI, phosphoglycerate mutase 2 (PGAM2, gelsolin and isoform 8 of titin. PGAM2, LDHB and titin were measured with enzyme-linked immunosorbent assays kits. The mean concentrations of LDHB and PGAM2 in samples showed an increasing trend when ischemic time was extending. In addition, 33% identified proteins are involved in metabolism. Protein to protein interaction network analysis showed glycolytic enzymes, such as isoform alpha-enolase of alpha-enolase, isoform 1 of triosephosphate isomerase and glyceraldehyde-3-phosphate dehydrogenase, had more connections than other

  10. Quantum-beat Auger spectroscopy

    CERN Document Server

    Zhang, Song Bin

    2015-01-01

    The concept of nonlinear quantum-beat pump-probe Auger spectroscopy is introduced by discussing a relatively simple four-level model system. We consider a coherent wave packet involving two low-lying states that was prepared by an appropriate pump pulse. This wave packet is subsequently probed by a weak, time-delayed probe pulse with nearly resonant coupling to a core-excited state of the atomic or molecular system. The resonant Auger spectra are then studied as a function of the duration of the probe pulse and the time delay. With a bandwidth of the probe pulse approaching the energy spread of the wave packet, the Auger yields and spectra show quantum beats as a function of pump-probe delay. An analytic theory for the quantum-beat Auger spectroscopy will be presented, which allows for the reconstruction of the wave packet by analyzing the delaydependent Auger spectra. The possibility of extending this method to a more complex manifold of electronic and vibrational energy levels is also discussed.

  11. Severe pneumonia after heart transplantation as a result of human parvovirus B19.

    Science.gov (United States)

    Janner, D; Bork, J; Baum, M; Chinnock, R

    1994-01-01

    The diverse manifestations of human parvovirus B19 infection have been well established. Erythema infectiosum, fetal hydrops, adult arthropathy, and aplastic anemia in patients with hemoglobinopathies or underlying immunocompromise have been described. Recently we successfully treated a patient who, after heart transplantation, had fever, rash, and pneumonia with respiratory failure caused by human parovirus B19. Human parovirus B19 has not been reported previously as a pathogen causing pulmonary disease after pediatric heart transplantation, and we wish to report it at this time.

  12. Effect of contractile protein alterations on cardiac myofilament function in human heart failure

    NARCIS (Netherlands)

    Narolska, N.A.

    2006-01-01

    The main objective of this thesis was to elucidate the effect of translational and post-translational alterations in contractile proteins occurring during heart failure on contractile function in human cardiac tissue. Isometric force and ATPase activity measurements were performed in skinned human

  13. High expression of arachidonate 15-lipoxygenase and proinflammatory markers in human ischemic heart tissue

    Energy Technology Data Exchange (ETDEWEB)

    Magnusson, Lisa U.; Lundqvist, Annika [Sahlgrenska Center for Cardiovascular and Metabolic Research, Wallenberg Laboratory, Department of Molecular and Clinical Medicine, Institute of Medicine, Sahlgrenska Academy, University of Gothenburg, Sahlgrenska University Hospital, Gothenburg (Sweden); Asp, Julia [Department of Clinical Chemistry and Transfusion Medicine, Institute of Biomedicine, Sahlgrenska Academy, University of Gothenburg, Gothenburg (Sweden); Synnergren, Jane [Systems Biology Research Center, School of Life Sciences, University of Skoevde, Skoevde (Sweden); Johansson, Cecilia Thalen [Sahlgrenska Center for Cardiovascular and Metabolic Research, Wallenberg Laboratory, Department of Molecular and Clinical Medicine, Institute of Medicine, Sahlgrenska Academy, University of Gothenburg, Sahlgrenska University Hospital, Gothenburg (Sweden); Palmqvist, Lars [Department of Clinical Chemistry and Transfusion Medicine, Institute of Biomedicine, Sahlgrenska Academy, University of Gothenburg, Gothenburg (Sweden); Jeppsson, Anders [Department of Cardiothoracic Surgery, Sahlgrenska University Hospital, Gothenburg (Sweden); Hulten, Lillemor Mattsson, E-mail: Lillemor.Mattsson@wlab.gu.se [Sahlgrenska Center for Cardiovascular and Metabolic Research, Wallenberg Laboratory, Department of Molecular and Clinical Medicine, Institute of Medicine, Sahlgrenska Academy, University of Gothenburg, Sahlgrenska University Hospital, Gothenburg (Sweden)

    2012-07-27

    Highlights: Black-Right-Pointing-Pointer We found a 17-fold upregulation of ALOX15 in the ischemic heart. Black-Right-Pointing-Pointer Incubation of human muscle cells in hypoxia showed a 22-fold upregulation of ALOX15. Black-Right-Pointing-Pointer We observed increased levels of proinflammatory markers in ischemic heart tissue. Black-Right-Pointing-Pointer Suggesting a link between ischemia and inflammation in ischemic heart biopsies. -- Abstract: A common feature of the ischemic heart and atherosclerotic plaques is the presence of hypoxia (insufficient levels of oxygen in the tissue). Hypoxia has pronounced effects on almost every aspect of cell physiology, and the nuclear transcription factor hypoxia inducible factor-1{alpha} (HIF-1{alpha}) regulates adaptive responses to low concentrations of oxygen in mammalian cells. In our recent work, we observed that hypoxia increases the proinflammatory enzyme arachidonate 15-lipoxygenase (ALOX15B) in human carotid plaques. ALOX15 has recently been shown to be present in the human myocardium, but the effect of ischemia on its expression has not been investigated. Here we test the hypothesis that ischemia of the heart leads to increased expression of ALOX15, and found an almost 2-fold increase in HIF-1{alpha} mRNA expression and a 17-fold upregulation of ALOX15 mRNA expression in the ischemic heart biopsies from patients undergoing coronary bypass surgery compared with non ischemic heart tissue. To investigate the effect of low oxygen concentration on ALOX15 we incubated human vascular muscle cells in hypoxia and showed that expression of ALOX15 increased 22-fold compared with cells incubated in normoxic conditions. We also observed increased mRNA levels of proinflammatory markers in ischemic heart tissue compared with non-ischemic controls. In summary, we demonstrate increased ALOX15 in human ischemic heart biopsies. Furthermore we demonstrate that hypoxia increases ALOX15 in human muscle cells. Our results yield

  14. Type 2 diabetes, obesity, and sex difference affect the fate of glucose in the human heart

    OpenAIRE

    Peterson, Linda R.; Herrero, Pilar; Coggan, Andrew R.; Kisrieva-Ware, Zulia; Saeed, Ibrahim; Dence, Carmen; Koudelis, Deborah; McGill, Janet B.; Lyons, Matthew R.; Novak, Eric; Dávila-Román, Víctor G.; Waggoner, Alan D.; Gropler, Robert J.

    2015-01-01

    Type 2 diabetes, obesity, and sex difference affect myocardial glucose uptake and utilization. However, their effect on the intramyocellular fate of glucose in humans has been unknown. How the heart uses glucose is important, because it affects energy production and oxygen efficiency, which in turn affect heart function and adaptability. We hypothesized that type 2 diabetes, sex difference, and obesity affect myocardial glucose oxidation, glycolysis, and glycogen production. In a first-in-hum...

  15. THREE DIMENSIONAL RECONSTRUCTION OF HUMAN HEART SURFACE FROM SINGLE IMAGE- VIEW UNDER DIFFERENT ILLUMINATION CONDITIONS

    Directory of Open Access Journals (Sweden)

    Aqeel Al-Surmi

    2013-01-01

    Full Text Available The 3D reconstruction from a single-view image is a longstanding issue in computer vision literature, especially in the medical field. Traditional medical imaging techniques that provide information about the heart and which are used to reconstruct the heart model, include Magnetic Resonance Imaging (MRI and Computed Tomography (CT images. However, in some cases, they are not available and the applications that use these techniques to model the human heart only produce acceptable results after a long process, which involves acquiring the input data, as well as the segmentation process, the matching process, effort and cost. Therefore, it would be useful to be able to use a 2D single image to reconstruct the 3D heart surface model. We introduce an image-based human heart surface reconstruction from a single image as input. To model the surface of the heart, the proposed method, first, detects and corrects the specular reflection from the heart’s surface, which causes deformation of the surface in the R3. Second, it extrudes the three axes for each image pixel (e.g., x, y and z axes from the input image, in which the z-axis is calculated using the intensity value. Finally, a 3D reconstruction of the heart surface is created to help the novice cardiac surgeon to reduce the period of time in learning cardiac surgery and to enhance their perception of the operating theatre. The experimental results for images of the heart show the efficiency of the proposed method compared to the existing methods.

  16. 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.

  17. Popeye domain-containing 1 is down-regulated in failing human hearts.

    Science.gov (United States)

    Gingold-Belfer, Rachel; Bergman, Michael; Alcalay, Yifat; Schlesinger, Hadassa; Aravot, Dan; Berman, Marius; Salman, Hertzel; Brand, Thomas; Kessler-Icekson, Gania

    2011-01-01

    Congestive heart failure, a complex disease of heterogeneous etiology, involves alterations in the expression of multiple genes. The Popeye domain-containing (POPDC) family of three novel muscle-restricted genes (POPDC1-3) is evolutionarily conserved and developmentally regulated. In mice, POPDC1 has been shown to play an important role in skeletal and cardiac muscles subjected to injury or stress. However, it has never been explored in human hearts. In biopsies from non-failing and failing human hearts, we examined the cellular distribution of POPDC1 as well as the expression patterns of POPDC1-3 mRNAs. POPDC1 was visualized by immunohistochemistry and estimated by Western immunoblotting. The mRNA levels of POPDC1-3 and ß myosin heavy chain (MYHC7) were assessed using reverse transcription/quantitative polymerase chain reaction. POPDC1 was predominantly localized in the sarcolemma with an enhanced expression in the intercalated discs. In failing hearts, many cardiomyocytes appeared deformed and POPDC1 labeling was deranged. The three POPDC mRNAs were expressed in the four heart chambers with higher transcript levels in the ventricles compared to the atria. Heart failure concurred with reduced levels of POPDC1 mRNA and protein in the left ventricle. Correlation analyses of mRNA levels among the failing heart specimens indicated the coordinated regulation of POPDC1 with POPDC3 and of POPDC2 with MYHC7. It can be concluded that POPDC gene expression is modified in end-stage heart failure in humans in a manner suggesting regulatory and/or functional differences between the three family members and that POPDC1 is particularly susceptible to this condition.

  18. Population-based beat-to-beat QT analysis from Holter recordings in the long QT syndrome.

    Science.gov (United States)

    Page, Alex; McNitt, Scott; Xia, Xiaojuan; Zareba, Wojciech; Couderc, Jean-Philippe

    2017-08-10

    The increasing dissemination of wearable ECG recorders (e.g. Holter, patches, and strap sensors) enables the acquisition of large amounts of data during long periods of time. However, the clinical value of these long-term continuous recordings is hindered by the lack of automatic tools to extract clinically relevant information (other than non-sinus and life-threatening rhythms) from such long-term data, particularly when targeting population-based research. In this work, we propose and test a new tool for analyzing beat-to-beat interval measurements and extracting features from Holter ECGs. Specifically, we assess the adaptation of the QT interval following sudden changes in heart rate in the primary long QT types (1 & 2). We find that in long QT syndrome type 2, certain QT adaptation patterns can indicate a higher risk for cardiac events. Copyright © 2017 Elsevier Inc. All rights reserved.

  19. Extra-corporeal membrane oxygenation during the beating heart coronary artery bypass grafting for ;high risk patients-a single center experience%体外膜肺氧合在高危重症冠心病患者心脏不停跳冠状动脉旁路移植术中的应用

    Institute of Scientific and Technical Information of China (English)

    段大为; 刘迎午; 胡晓旻; 刘博江; 吴鹏; 张强; 李彤

    2016-01-01

    目的:总结体外膜肺氧合( extra-corporeal membrane oxygenation,ECMO)在高危重症冠心病患者心脏不停跳冠状动脉旁路移植术( coronary artery bypass grafting,CABG)中的应用方法和效果。方法选取2007年11月至2014年6月天津市第三中心医院心脏外科的高危重症冠心病行CABG术患者21例,年龄70~83(75.7±3.6)岁,在ECMO辅助下实施择期心脏不停跳CABG术。结果21例患者中,8例术后即刻顺利脱离ECMO辅助;8例桥血管吻合后ECMO不能立即撤离,继续辅助2.0~4.5 h 后撤离;5例在手术室时 ECMO 不能撤离,关胸后返回冠心病重症监护病房( CCU),考虑ECMO辅助时间较长,为克服ECMO非搏动性灌注,联合主动脉内球囊反搏( intra-aortic balloon pump,IABP)支持,IABP辅助时间76~147(115.2±25.9)h。5例CCU内ECMO辅助患者中:股动静脉插管部位渗血1例,经止血及加压包扎后好转;下肢缺血1例,安装旁路循环后缺血改善;均顺利脱机。21例患者均康复出院,住院时间11~28(17.4±2.8) d。结论 ECMO用于心脏不停跳CABG术可为高危重症冠心病患者提供手术治疗的支持和保护。%Objective To summarize clinical application, method and result of extra-corporeal membrane oxygenation ( ECMO) used during beating heart coronary artery bypass grafting ( CABG) in high risk patients. Methods Twenty one patients [ mean age ( 75. 7 ± 3. 6 ) years old ] who received beating-heart CABG surgery assisted with ECMO were included in the study. We observed the condition when ECMO weaned off, the duration on mechanical rentilato time of ICU stay and the occurance of related complications. Results Among the 21 patients, ECMO was weaned off uneventfully after surgery in 8 patients. Immediate weaning was failed in another 8 patients and required gradual weaning in 2. 0-4. 5 hrs. Five patients could not wean off the ECMO in operation room needing continuous ECMO support in CCU. ECMO was weaned off in CCU gradually with

  20. 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.

  1. Triboelectric Nanogenerator Enabled Body Sensor Network for Self-Powered Human Heart-Rate Monitoring.

    Science.gov (United States)

    Lin, Zhiming; Chen, Jun; Li, Xiaoshi; Zhou, Zhihao; Meng, Keyu; Wei, Wei; Yang, Jin; Wang, Zhong Lin

    2017-09-26

    Heart-rate monitoring plays a critical role in personal healthcare management. A low-cost, noninvasive, and user-friendly heart-rate monitoring system is highly desirable. Here, a self-powered wireless body sensor network (BSN) system is developed for heart-rate monitoring via integration of a downy-structure-based triboelectric nanogenerator (D-TENG), a power management circuit, a heart-rate sensor, a signal processing unit, and Bluetooth module for wireless data transmission. By converting the inertia energy of human walking into electric power, a maximum power of 2.28 mW with total conversion efficiency of 57.9% was delivered at low operation frequency, which is capable of immediately and sustainably driving the highly integrated BSN system. The acquired heart-rate signal by the sensor would be processed in the signal process circuit, sent to an external device via the Bluetooth module, and displayed on a personal cell phone in a real-time manner. Moreover, by combining a TENG-based generator and a TENG-based sensor, an all-TENG-based wireless BSN system was developed, realizing continuous and self-powered heart-rate monitoring. This work presents a potential method for personal heart-rate monitoring, featured as being self-powered, cost-effective, noninvasive, and user-friendly.

  2. Effects of rat/mouse hemokinin-1, human hemokinin-1 and human hemokinin-1(4-11), mammalian tachykinin peptides, on rate and perfusion pressure in the isolated guinea pig heart.

    Science.gov (United States)

    Kong, Zi-Qing; Yang, Wen-Le; Tao, Yan; Shi, Xiao-Mei; Fu, Cai-Yun; Zhao, Rui-Fei; Wang, Rui

    2010-10-01

    Rat/mouse hemokinin-1 (r/m HK-1), human hemokinin-1 (h HK-1) and human hemokinin-1(4-11) (h HK-1(4-11)) are members of the tachykinin family. In the present study, the coronary vascular activities and cardiac functions of r/m HK-1, h HK-1 and h HK-1(4-11) were investigated in isolated, spontaneously beating guinea pig hearts. Bolus injections of r/m HK-1 caused decrease in perfusion pressure indicative of coronary vasodilation, which was primarily due to the action on tachykinin NK1 receptors on vascular endothelial cells, causing the release of nitric oxide that relaxed the coronary vessels. H HK-1 caused biphasic perfusion pressure changes that were coronary vasodilation followed by coronary vasoconstriction. The mechanisms involved in the vasodilation induced by h HK-1 were similar to that of r/m HK-1 while the mechanisms for coronary vasoconstriction were mediated through the activation of tachykinin NK2 receptors on coronary sympathetic neurons to release catecholamines. H HK-1(4-11) only produced coronary vasoconstriction and the mechanisms involved in this effect were similar to that of h HK-1 in vasoconstriction. Moreover, r/m HK-1 and h HK-1 produced similar decreases in heart rate indicative of negative chronotropic responses and the decreases were mainly mediated through the activation of tachykinin NK1 receptors to release ACh acting on muscarinic receptors. H HK-1(4-11) also produced negative chronotropic response, which was mainly mediated through tachykinin NK2 receptors and muscarinic receptors. Our present results provide evidence that all of the three tachykinins could influence cardiac function and coronary vascular activity in the isolated guinea pig heart. 2010 Elsevier Ltd. All rights reserved.

  3. Integrated Transcriptome Map Highlights Structural and Functional Aspects of the Normal Human Heart.

    Science.gov (United States)

    Caracausi, Maria; Piovesan, Allison; Vitale, Lorenza; Pelleri, Maria Chiara

    2017-04-01

    A systematic meta-analysis of the available gene expression profiling datasets for the whole normal human heart generated a quantitative transcriptome reference map of this organ. Transcriptome Mapper (TRAM) software integrated 32 gene expression profile datasets from different sources returning a reference value of expression for each of the 43,360 known, mapped transcripts assayed by any of the experimental platforms used in this regard. Main findings include the visualization at the gene and chromosomal levels of the classical description of the basic histology and physiology of the heart, the identification of suitable housekeeping reference genes, the analysis of stoichiometry of gene products, and the focusing on chromosome 21 genes, which are present in one excess copy in Down syndrome subjects, presenting cardiovascular defects in 30-40% of cases. Independent in vitro validation showed an excellent correlation coefficient (r = 0.98) with the in silico data. Remarkably, heart/non-cardiac tissue expression ratio may also be used to anticipate that effects of mutations will most probably affect or not the heart. The quantitative reference global portrait of gene expression in the whole normal human heart illustrates the structural and functional aspects of the whole organ and is a general model to understand the mechanisms underlying heart pathophysiology. J. Cell. Physiol. 232: 759-770, 2017. © 2016 Wiley Periodicals, Inc.

  4. Bondage fantasies and beating fantasies.

    Science.gov (United States)

    Weiss, J

    1998-10-01

    Two male patients had masochistic sexual fantasies: one had bondage fantasies, the other beating fantasies. Each patient had been traumatized in childhood by his experiences with a martyr mother. Each had developed the belief that in an intimate sexual relationship with a woman he would hurt her. As a consequence, each tended to suppress his sexuality. Each used masochistic fantasies to reassure himself that he was not hurting his fantasied or real partner. The reassurance made it safe to experience his sexual feelings. The two patients' use of their masochistic fantasies is compared to the fetishist's use of his fetish, as described by Freud.

  5. Spectroscopic fluorescence measurements of lamb and human heart tissue in vitro

    Science.gov (United States)

    Filippidis, George; Zacharakis, Giannis; Kochiadakis, G. E.; Chrysostomakis, S. I.; Vardas, P. E.; Fotakis, Costas; Papazoglou, Theodore G.

    2003-10-01

    Laser-induced fluorescence spectra were obtained during the exposure of lamb heart (n=20) tissue to Argon-ion radiation (457.9nm). Fluorescence spectra from different heart compartments (the left and right atria and ventricles, the myocardium, the epicardium, and the aorta) were recorded. Simple algebraic algorithms based on the spectral intensity variation were constructed in order to detect spectral features and characterize the different cardiac compartments. Additionally, it was investigated whether each chamber exhibited constant spectral response. After the end of each experiment the lamb hearts were stored in formalin (10%). The samples were irradiated again after forty eight (48) hours in order to investigate the spectral differences that appear due to formalin conservation. Similar fluorescence measurements were taken from a limited number of human heart tissues (n=2) ex vivo.

  6. Autonomic control of the heart during exercise in humans: role of skeletal muscle afferents.

    Science.gov (United States)

    Fisher, James P

    2014-02-01

    What is the topic of this review? The autonomic nervous system plays a key role in bringing about the cardiovascular responses to exercise necessitated by the increased metabolic requirements of the active skeletal muscle. The complex interaction of central and peripheral neural control mechanisms evokes a decrease in parasympathetic activity and an increase sympathetic activity to the heart during exercise. What advances does it highlight? This review presents some of the recent insights provided by human studies into the role of mechanically and metabolically sensitive skeletal muscle afferents in the regulation of cardiac autonomic control during exercise. The autonomic responses to exercise are orchestrated by the interactions of several central and peripheral neural mechanisms. This report focuses on the role of peripheral feedback from skeletal muscle afferents in the autonomic control of the heart during exercise in humans. Heart rate responses to passive calf stretch are abolished with cardiac parasympathetic blockade, indicating that the activation of mechanically sensitive skeletal muscle afferents (muscle mechanoreceptors) can inhibit cardiac parasympathetic activity and is likely to contribute to the increase in heart rate at the onset of exercise. Recent experiments show that the partial restriction of blood flow to the exercising skeletal muscles, to augment the activation of metabolically sensitive skeletal muscle afferents (muscle metaboreceptors) in humans, evokes an increase in heart rate that is attenuated with β1-adrenergic blockade, thus suggesting that this response is principally mediated via an increase in cardiac sympathetic activity. Heart rate remains at resting levels during isolated activation of muscle metaboreceptors with postexercise ischaemia following hand grip, unless cardiac parasympathetic activity is inhibited, whereupon a sympathetically mediated increase in heart rate is unmasked. During postexercise ischaemia following leg

  7. Unattended musical beats enhance visual processing.

    Science.gov (United States)

    Escoffier, Nicolas; Sheng, Darren Yeo Jian; Schirmer, Annett

    2010-09-01

    The present study investigated whether and how a musical rhythm entrains a listener's visual attention. To this end, participants were presented with pictures of faces and houses and indicated whether picture orientation was upright or inverted. Participants performed this task in silence or with a musical rhythm playing in the background. In the latter condition, pictures could occur off-beat or on a rhythmically implied, silent beat. Pictures presented without the musical rhythm and off-beat were responded to more slowly than pictures presented on-beat. This effect was comparable for faces and houses. Together these results indicate that musical rhythm both synchronizes and facilitates concurrent stimulus processing.

  8. Linking the Heart and the Head: Humanism and Professionalism in Medical Education and Practice.

    Science.gov (United States)

    Montgomery, Lynda; Loue, Sana; Stange, Kurt C

    2017-05-01

    This paper articulates a practical interpretive framework for understanding humanism in medicine through the lens of how it is taught and learned. Beginning with a search for key tensions and relevant insights in the literature on humanism in health professions education, we synthesized a conceptual model designed to foster reflection and action to realize humanistic principles in medical education and practice. The resulting model centers on the interaction between the heart and the head. The heart represents the emotive domains of empathy, compassion, and connectedness. The head represents the cognitive domains of knowledge, attitudes, and beliefs. The cognitive domains often are associated with professionalism, and the emotive domains with humanism, but it is the connection between the two that is vital to humanistic education and practice. The connection between the heart and the head is nurtured by critical reflection and conscious awareness. Four provinces of experience nurture humanism: (1) personal reflection, (2) action, (3) system support, and (4) collective reflection. These domains represent potential levers for developing humanism. Critical reflection and conscious awareness between the heart and head through personal reflection, individual and collective behavior, and supportive systems has potential to foster humanistic development toward healing and health.

  9. Regional pulmonary perfusion following human heart-lung transplantation

    Energy Technology Data Exchange (ETDEWEB)

    Lisbona, R.; Hakim, T.S.; Dean, G.W.; Langleben, D.; Guerraty, A.; Levy, R.D. (Royal Victoria Hospital, Montreal, Quebec (Canada))

    1989-08-01

    Ventilation and perfusion scans were obtained in six subjects who had undergone heart-lung transplantation with consequent denervation of the cardiopulmonary axis. Two of the subjects had developed obliterative bronchiolitis, which is believed to be a form of chronic rejection. Their pulmonary function tests demonstrated airflow obstruction and their scintigraphic studies were abnormal. In the remaining four subjects without obstructive airways disease, ventilation and planar perfusion scans were normal. Single photon emission computed tomography imaging of pulmonary perfusion in these patients revealed a layered distribution of blood flow indistinguishable from that of normal individuals. It is concluded that neurogenic mechanisms have little influence on the pattern of local pulmonary blood flow at rest.

  10. Keeping the Beat: A Large Sample Study of Bouncing and Clapping to Music

    Science.gov (United States)

    Tranchant, Pauline; Vuvan, Dominique T.; Peretz, Isabelle

    2016-01-01

    The vast majority of humans move in time with a musical beat. This behaviour has been mostly studied through finger-tapping synchronization. Here, we evaluate naturalistic synchronization responses to music–bouncing and clapping–in 100 university students. Their ability to match the period of their bounces and claps to those of a metronome and musical clips varying in beat saliency was assessed. In general, clapping was better synchronized with the beat than bouncing, suggesting that the choice of a specific movement type is an important factor to consider in the study of sensorimotor synchronization processes. Performance improved as a function of beat saliency, indicating that beat abstraction plays a significant role in synchronization. Fourteen percent of the population exhibited marked difficulties with matching the beat. Yet, at a group level, poor synchronizers showed similar sensitivity to movement type and beat saliency as normal synchronizers. These results suggest the presence of quantitative rather than qualitative variations when losing the beat. PMID:27471854

  11. Human bone marrow-derived mesenchymal stem cells transplanted into damaged rabbit heart to improve heart function

    Institute of Scientific and Technical Information of China (English)

    WANG Jian-an; FAN You-qi; LI Chang-ling; HE Hong; SUN Yong; LV Bin-jian

    2005-01-01

    Objective: The present study was designed to test whether transplantation of human bone marrow-derived mesenchymal stem cells (hMSCs) in New Zealand rabbits with myocardial infarction can improve heart function; and whether engrafted donor cells can survive and transdifferentiated into cardiomyocytes. Methods: Twenty milliliters bone marrow was obtained from healthy men by bone biopsy. A gradient centrifugation method was used to separate bone marrow cells (BMCs) and red blood cells.BMCs were incubated for 48 h and then washed with phosphate-buffered saline (PBS). The culture medium was changed twice a week for 28 d. Finally, hematopoietic cells were washed away to leave only MSCs. Human MSCs (hMSCs) were premarked by BrdU 72 h before the transplantation. Thirty-four New Zealand rabbits were randomly divided into myocardial infarction (MI)control group and cell treated group, which received hMSCs (MI+MSCs) through intramyocardial injection, while the control group received the same volume of PBS. Myocardial infarction was induced by ligation of the left coronary artery. Cell treated rabbits were treated with 5× 106 MSCs transplanted into the infarcted region after ligation of the coronary artery for 1 h, and the control group received the same volume of PBS. Cyclosporin A (oral solution; 10 mg/kg) was provided alone, 24 h before surgery and once a day after MI for 4 weeks. Echocardiography was measured in each group before the surgery and 4 weeks after the surgery to test heart function change. The hearts were harvested for HE staining and immunohistochemical studies after MI and cell transplantation for 4 weeks. Results: Our data showed that cardiac function was significantly improved by hMSC transplantation in rabbit infarcted hearts 4 weeks after MI (ejection fraction: 0.695±0.038 in the cell treated group (n=12) versus0.554±0.065 in the control group (n=13) (P<0.05). Surviving hMSCs were identified by BrdU positive spots in infarcted region and

  12. Comparación de los resultados de la revascularización miocárdica con corazón latiente, con circulación extracorpórea y sin ella Comparison of results of myocardial revascularization with beating heart, with and without extracorporeal circulation

    Directory of Open Access Journals (Sweden)

    Eider Daniel Echemendía Simón

    2011-03-01

    órea como ayuda en la revascularización miocárdica con el corazón latiendo arrojó resultados insatisfactorios.INTRODUCTION. The surgical myocardial revascularization with beating heart and without extracorporeal circulation (ECC is a potential strategy to decrease the mortality and the morbidity in patients presenting with ischemic heart disease. The objective of present research was to describe the results of surgical myocardial revascularization with beating heart, with or without ECC. METHODS. A prospective, longitudinal and descriptive study was conducted of cases series type where the sample included 159 patients underwent beating heart myocardial revascularization (143 without ECC and 16 with EEC en the "Hermanos Ameijeiras" Clinical Surgical Hospital in 2007. RESULTS. The mean age of the 159 patients operated on was of 63,9 years. There was predominance of male sex (74,2%, white race (81,1%, chronic and stable exertion angina (86,8%, dyslipidemia (84,3%, high blood pressure (81,2%, use of two or more anti-ischemia drugs (83,0%, III functional class (64,2%, sinus cardiac rhythm (98,1%, trunk lesion associated to multi-vessel disease (54,1% and sternotomy approach (93,1%. There were statistically significant differences in favor of the patients without ECC as regards the complete revascularization (p = 0,006, inotropic drugs (p = 0,000, haemoderivatives (p = 0,022, surgical time (p = 0,000 and anesthetics (p = 0,000, use of contrapulsation balloon (p = 0,001, medium extubation (p = 0,003 and intensive care unit stay (p = 0,011. The overall mortality was of 5,0%, more significant when ECC was used (p = 0,001 and similar when both techniques were compared in relation to respiratory sepsis, renal dysfunction, pleural effusion, low cardiac output, postoperative hemorrhage and decompensation of diabetes mellitus. CONCLUSIONS. We conclude that the use of extracorporeal circulation as help in beating heart myocardial revascularization yielded unsatisfactory results.

  13. MORPHOLOGICAL STUDY OF CORONARY SINUS IN HUMAN CADAVERIC HEARTS

    Directory of Open Access Journals (Sweden)

    R. Manoranjitham

    2015-09-01

    Full Text Available Background: The coronary sinus is a dilated venous channel opening into the right atrium of the heart. The coronary venous system has gained importance in recent years for electrophysiological procedures like arrhythmia ablation, biventricular pacing and implantation of cardiac pacemakers. The present study aims to study the formation and tributaries of coronary sinus and also the morphology of thebesian valve. Materials and Methods: 30 formalin fixed cadaveric hearts available in the department of Anatomy, Dhanalakshmi Srinivasan Medical College and Hospital, Perambalur, Tamil nadu, was used for the study. The formation and tributaries of coronary sinus were noted. The length of coronary sinus in millimeters was measured from the union of great cardiac vein and left marginal vein upto the opening of the coronary sinus in the right atrium with vernier calipers. The width of the coronary ostium in the right atrium was measured in millimeters with vernier calipers. Results: In 93.33% specimens the coronary sinus was formed by the union of great cardiac vein and left marginal vein. In 3.33% specimens it was formed by the union of great cardiac vein and posterior vein of left ventricle, and in 3.33% specimens it was formed by the union of great cardiac vein and oblique vein of left atrium. The left marginal vein was absent in 2 specimens and small cardiac vein was absent in 1 specimen. The mean length of coronary sinus was 54.98 + 12.2mm. The mean width of coronary sinus ostium was 9.35 + 3.24mm. The Thebesian valve was present in 93.33% specimens and it was semilunar in shape. Conclusion: The knowledge of coronary sinus anatomy will be helpful during electrophysiological procedures.

  14. Quantification of carbonic anhydrase gene expression in ventricle of hypertrophic and failing human heart

    Directory of Open Access Journals (Sweden)

    Alvarez Bernardo V

    2013-01-01

    Full Text Available Abstract Background Carbonic anhydrase enzymes (CA catalyze the reversible hydration of carbon dioxide to bicarbonate in mammalian cells. Trans-membrane transport of CA-produced bicarbonate contributes significantly to cellular pH regulation. A body of evidence implicates pH-regulatory processes in the hypertrophic growth pathway characteristic of hearts as they fail. In particular, Na+/H+ exchange (NHE activation is pro-hypertrophic and CA activity activates NHE. Recently Cardrase (6-ethoxyzolamide, a CA inhibitor, was found to prevent and revert agonist-stimulated cardiac hypertrophy (CH in cultured cardiomyocytes. Our goal thus was to determine whether hypertrophied human hearts have altered expression of CA isoforms. Methods We measured CA expression in hypertrophied human hearts to begin to examine the role of carbonic anhydrase in progression of human heart failure. Ventricular biopsies were obtained from patients undergoing cardiac surgery (CS, n = 14, or heart transplantation (HT, n = 13. CS patients presented mild/moderate concentric left ventricular hypertrophy and normal right ventricles, with preserved ventricular function; ejection fractions were ~60%. Conversely, HT patients with failing hearts presented CH or ventricular dilation accompanied by ventricular dysfunction and EF values of 20%. Non-hypertrophic, non-dilated ventricular samples served as controls. Results Expression of atrial and brain natriuretic peptide (ANP and BNP were markers of CH. Hypertrophic ventricles presented increased expression of CAII, CAIV, ANP, and BNP, mRNA levels, which increased in failing hearts, measured by quantitative real-time PCR. CAII, CAIV, and ANP protein expression also increased approximately two-fold in hypertrophic/dilated ventricles. Conclusions These results, combined with in vitro data that CA inhibition prevents and reverts CH, suggest that increased carbonic anhydrase expression is a prognostic molecular marker of cardiac

  15. Heart Rate Variability Measures and Models

    CERN Document Server

    Teich, M C; Jost, B M; Vibe-Rheymer, K; Heneghan, C; Teich, Malvin C.; Lowen, Steven B.; Jost, Bradley M.; Vibe-Rheymer, Karin; Heneghan, Conor

    2001-01-01

    We focus on various measures of the fluctuations of the sequence of intervals between beats of the human heart, and how such fluctuations can be used to assess the presence or likelihood of cardiovascular disease. We examine sixteen such measures and their suitability for correctly classifying heartbeat records of various lengths as normal or revealing the presence of cardiac dysfunction, particularly congestive heart failure. Using receiver-operating-characteristic analysis we demonstrate that scale-dependent measures prove substantially superior to scale-independent ones. The wavelet-transform standard deviation at a scale near 32 heartbeat intervals, and its spectral counterpart near 1/32 cycles/interval, turn out to provide reliable results using heartbeat records just minutes long. We further establish for all subjects that the human heartbeat has an underlying stochastic origin rather than arising from a chaotic attractor. Finally, we develop a mathematical point process that emulates the human heartbea...

  16. Hypertrophy of neurons within cardiac ganglia in human, canine, and rat heart failure: the potential role of nerve growth factor.

    Science.gov (United States)

    Singh, Sanjay; Sayers, Scott; Walter, James S; Thomas, Donald; Dieter, Robert S; Nee, Lisa M; Wurster, Robert D

    2013-08-19

    Autonomic imbalances including parasympathetic withdrawal and sympathetic overactivity are cardinal features of heart failure regardless of etiology; however, mechanisms underlying these imbalances remain unknown. Animal model studies of heart and visceral organ hypertrophy predict that nerve growth factor levels should be elevated in heart failure; whether this is so in human heart failure, though, remains unclear. We tested the hypotheses that neurons in cardiac ganglia are hypertrophied in human, canine, and rat heart failure and that nerve growth factor, which we hypothesize is elevated in the failing heart, contributes to this neuronal hypertrophy. Somal morphology of neurons from human (579.54±14.34 versus 327.45±9.17 μm(2); Phypertrophy of neurons in cardiac ganglia compared with controls. Western blot analysis shows that nerve growth factor levels in the explanted, failing human heart are 250% greater than levels in healthy donor hearts. Neurons from cardiac ganglia cultured with nerve growth factor are significantly larger and have greater dendritic arborization than neurons in control cultures. Hypertrophied neurons are significantly less excitable than smaller ones; thus, hypertrophy of vagal postganglionic neurons in cardiac ganglia would help to explain the parasympathetic withdrawal that accompanies heart failure. Furthermore, our observations suggest that nerve growth factor, which is elevated in the failing human heart, causes hypertrophy of neurons in cardiac ganglia.

  17. Sleep Stage Dependence of Invariance Characteristics in Fluctuations of Healthy Human Heart Rate

    Science.gov (United States)

    Togo, Fumiharu; Kiyono, Ken; Struzik, Zbigniew R.; Yamamoto, Yoshiharu

    2005-08-01

    The outstanding feature of healthy human heart rate is the robust scale invariance in the non-Gaussian probability density function (PDF), which is preserved not only in a quiescent condition, but also in a dynamic state during waking hours [K. Kiyono et al. Phys. Rev. Lett. 93 (2004)]. Together with 1/f like scaling, this characteristic is a strong indication of far-from-equilibrium, critical-like dynamics of heart rate regulation. Our results suggest that healthy human heart rate departs from a critical state-like operation during sleeping hours, at a rate which is heterogeneous with respect to sleep stages annotated according to traditional techniques. We study specific contributions of sleep stages to the relative departure from criticality through the analysis of sleep stage dependence of the root mean square of multiscale local energy and the multiscale PDF. There is a possibility that the involvement of cortical activity may be important for a critical state-like operation.

  18. Metabolic gene profile in early human fetal heart development

    National Research Council Canada - National Science Library

    Iruretagoyena, J I; Davis, W; Bird, C; Olsen, J; Radue, R; Teo Broman, A; Kendziorski, C; Splinter BonDurant, S; Golos, T; Bird, I; Shah, D

    2014-01-01

    .... In order to describe normal cardiac development during late first and early second trimester in human fetuses this study used microarray and pathways analysis and created a corresponding 'normal' database...

  19. Heart rate responses provide an objective evaluation of human disturbance stimuli in breeding birds.

    Science.gov (United States)

    Ellenberg, Ursula; Mattern, Thomas; Seddon, Philip J

    2013-01-01

    Intuition is a poor guide for evaluating the effects of human disturbance on wildlife. Using the endangered Yellow-eyed penguin, Megadyptes antipodes, as an example, we show that heart rate responses provide an objective tool to evaluate human disturbance stimuli and encourage the wider use of this simple and low-impact approach. Yellow-eyed penguins are a flagship species for New Zealand's wildlife tourism; however, unregulated visitor access has recently been associated with reduced breeding success and lower first year survival. We measured heart rate responses of Yellow-eyed penguins via artificial eggs to evaluate a range of human stimuli regularly occurring at their breeding sites. We found the duration of a stimulus to be the most important factor, with elevated heart rate being sustained while a person remained within sight. Human activity was the next important component; a simulated wildlife photographer, crawling slowly around during his stay, elicited a significantly higher heart rate response than an entirely motionless human spending the same time at the same distance. Stimuli we subjectively might perceive as low impact, such as the careful approach of a 'wildlife photographer', resulted in a stronger response than a routine nest-check that involved lifting a bird up to view nest contents. A single, slow-moving human spending 20 min within 2 m from the nest may provoke a response comparable to that of 10 min handling a bird for logger deployment. To reduce cumulative impact of disturbance, any human presence in the proximity of Yellow-eyed penguins needs to be kept at a minimum. Our results highlight the need for objective quantification of the effects of human disturbance in order to provide a sound basis for guidelines to manage human activity around breeding birds.

  20. Heart Devices 101: Guide to The Tools That Keep You Ticking

    Science.gov (United States)

    ... heart rhythm when the heart beats too slowly. Implantable cardioverter defibrillators : These deliver a shock to restore ... become blocked again. Ventricular assist devices : These mechanical pumps help weak hearts pump blood effectively. While originally ...

  1. Establishing human heart chromium, cobalt and vanadium concentrations by inductively coupled plasma mass spectrometry.

    Science.gov (United States)

    Day, Patrick L; Eckdahl, Steven J; Maleszewski, Joseph J; Wright, Thomas C; Murray, David L

    2017-05-01

    Chromium, cobalt, and vanadium are used in metallic joint prosthesis. Case studies have associated elevated heart tissue cobalt concentrations with myocardial injury. To document the long term heart metal ion concentrations, a validated inductively coupled plasma mass spectroscopy (ICP-MS) method was needed. The method utilized a closed-vessel microwave digestion system to digest the samples. An ICP-MS method utilizing Universal Cell Technology was used to determine our target analyte concentrations. Accuracy was verified using reference materials. Precision, sensitivity, recovery and linearity studies were performed. This method was used to establish a reference range for a non-implant containing cohort of 80 autopsy human heart tissues RESULTS: This method demonstrated an analytic measurement range of 0.5-100ng/mL for each element. Accuracy was within ±10% of target value for each element. Within-run precision for each element was below 20% CV. The chromium, vanadium and cobalt concentrations (mean±SD) were 0.1523±0.2157μg/g, 0.0094±0.0211μg/g and 0.1039±0.1305μg/g respectively in 80 non-implant containing human heart tissue samples. This method provides acceptable recovery of the chromium, cobalt and vanadium in heart tissue; allowing assessment of the effects of metallic joint prosthesis on myocardial health. Copyright © 2017 Elsevier GmbH. All rights reserved.

  2. Heart rate responses provide an objective evaluation of human disturbance stimuli in breeding birds

    OpenAIRE

    Ellenberg, Ursula; Mattern, Thomas; Seddon, Philip J.

    2013-01-01

    Intuition is a poor guide for evaluating the effects of human disturbance on wildlife. Using the endangered Yellow-eyed penguin, Megadyptes antipodes, as an example, we show that heart rate responses provide an objective tool to evaluate human disturbance stimuli and encourage the wider use of this simple and low-impact approach. Yellow-eyed penguins are a flagship species for New Zealand's wildlife tourism; however, unregulated visitor access has recently been associated with reduced breedin...

  3. Role of connexins in human congenital heart disease: the chicken and egg problem

    Directory of Open Access Journals (Sweden)

    Aida eSalameh

    2013-06-01

    Full Text Available Inborn cardiac diseases are among the most frequent congenital anomalies and are the main cause of death in infants within the first year of age in industrialized countries when not adequately treated. They can be divided into simple and complex cardiac malformations. The former ones, for instance atrial and ventricular septal defects, valvular or subvalvular stenosis or insufficiency account for up to 80% of cardiac abnormalities. The latter ones, for example transposition of the great vessels, Tetralogy of Fallot or Shone's anomaly often do not involve only the heart but also the great vessels and although occurring less frequently these severe cardiac malformations will become symptomatically within the first months of age and have a high risk of mortality if the patients remain untreated. In the last decade there is increasing evidence that cardiac gap junction proteins, the connexins (Cx, might have an impact on cardiac anomalies. In the heart mainly three of them (Cx40, Cx43 and Cx45 are differentially expressed with regard to temporal organogenesis and to their spatial distribution in the heart. These proteins, forming gap junction channels, are most important for a normal electrical conduction and coordinated synchronous heart muscle contraction and also for the normal embryonic development of the heart. Animal and also some human studies revealed that at least in some cardiac malformations alterations in certain gap junction proteins are present but until today no particular gap junction mutation could be assigned to a specific cardiac anomaly. As gap junctions transmit growth and differentiation signals from cell to cell it is reasonable to assume that they are somehow involved in misdirected growth present in many inborn heart diseases playing a primary or contributory role. This review addresses potential role of gap junctions in the development of inborn heart anomalies like the conotruncal heart defects.

  4. Role of connexins in human congenital heart disease: the chicken and egg problem.

    Science.gov (United States)

    Salameh, Aida; Blanke, Katja; Daehnert, Ingo

    2013-01-01

    Inborn cardiac diseases are among the most frequent congenital anomalies and are the main cause of death in infants within the first year of age in industrialized countries when not adequately treated. They can be divided into simple and complex cardiac malformations. The former ones, for instance atrial and ventricular septal defects, valvular or subvalvular stenosis or insufficiency account for up to 80% of cardiac abnormalities. The latter ones, for example transposition of the great vessels, Tetralogy of Fallot or Shone's anomaly often do not involve only the heart, but also the great vessels and although occurring less frequently, these severe cardiac malformations will become symptomatic within the first months of age and have a high risk of mortality if the patients remain untreated. In the last decade, there is increasing evidence that cardiac gap junction proteins, the connexins (Cx), might have an impact on cardiac anomalies. In the heart, mainly three of them (Cx40, Cx43, and Cx45) are differentially expressed with regard to temporal organogenesis and to their spatial distribution in the heart. These proteins, forming gap junction channels, are most important for a normal electrical conduction and coordinated synchronous heart muscle contraction and also for the normal embryonic development of the heart. Animal and also some human studies revealed that at least in some cardiac malformations alterations in certain gap junction proteins are present but until today no particular gap junction mutation could be assigned to a specific cardiac anomaly. As gap junctions have often been supposed to transmit growth and differentiation signals from cell to cell it is reasonable to assume that they are somehow involved in misdirected growth present in many inborn heart diseases playing a primary or contributory role. This review addresses the potentional role of gap junctions in the development of inborn heart anomalies like the conotruncal heart defects.

  5. 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.

  6. Signal processing of Shiley heart valve data for fracture detection

    Energy Technology Data Exchange (ETDEWEB)

    Mullenhoff, C.

    1993-04-01

    Given digital acoustic data emanating from the heart sounds of the beating heart measured from laboratory sheep with implanted Bjoerk-Shiley Convexo-Concave heart valves, it is possible to detect and extract the opening and closing heart beats from the data. Once extracted, spectral or other information can then obtained from the heartbeats and passed on to feature extraction algorithms, neutral networks, or pattern recognizers so that the valve condition, either fractured or intact, may be determined.

  7. Notes on the beating fantasy.

    Science.gov (United States)

    Sirois, François J

    2010-06-01

    This theoretical paper revisits the beating fantasy, which constitutes a crossroads of the psychic economy in that it condenses three primal phantasies, namely the primal scene, castration and seduction. Two forms of the phantasy have been distinguished: a 'fixed' form, apparently associated with the masochistic perversion, and a 'transitory' form, probably bound up with libidinal development. In Freud 's (1919) paper these two aspects are intertwined. The present contribution confines itself to the transitory form of the phantasy and its significance in the libidinal development of the girl, notably in the organization of passivity. With this in mind, particular attention is paid to the phantasy's third phase in this context, and an attempt made to show how this phase epitomizes the transformation of the instinctual pressure and might therefore be looked upon in this connection as the intermediate phase of the phantasy.

  8. Elastic interactions synchronize beating in cardiomyocytes.

    Science.gov (United States)

    Cohen, Ohad; Safran, Samuel A

    2016-07-13

    Motivated by recent experimental results, we study theoretically the synchronization of the beating phase and frequency of two nearby cardiomyocyte cells. Each cell is represented as an oscillating force dipole in an infinite, viscoelastic medium and the propagation of the elastic signal within the medium is predicted. We examine the steady-state beating of two nearby cells, and show that elastic interactions result in forces that synchronize the phase and frequency of beating in a manner that depends on their mutual orientation. The theory predicts both in-phase and anti-phase steady-state beating depending on the relative cell orientations, as well as how synchronized beating varies with substrate elasticity and the inter-cell distance. These results suggest how mechanics plays a role in cardiac efficiency, and may be relevant for the design of cardiomyocyte based micro devices and other biomedical applications.

  9. Human thoracic anatomy relevant to implantable artificial hearts

    Energy Technology Data Exchange (ETDEWEB)

    Jacobs, G.B.; Kiraly, R.J.; Nose, Y.

    1976-10-01

    The objective of the study is to define the human thorax in a quantitative statistical manner such that the information will be useful to the designers of cardiac prostheses, both total replacement and assist devices. This report pertains specifically to anatomical parameters relevant to the total cardiac prosthesis. This information will also be clinically useful in that the proposed recipient of a cardiac prosthesis can by simple radiography be assured of an adequate fit with the prosthesis prior to the implantation.

  10. Heart rate and heart rate variability responses to Tai Chi and jogging in Beijing and Graz.

    Science.gov (United States)

    Litscher, Gerhard; Zhang, Weibo; Huang, Tao; Wang, Lu

    2011-02-01

    Tai Chi is a famous training method in China, and jogging is a popular kind of exercise both in Austria and China. Nevertheless, there is little information concerning online monitoring of biosignals during both training activities in parallel. Within the last years innovative scientific monitoring tools for evaluating features of neurocardial fitness have been developed. The goal of this study was to demonstrate heart rate and heart rate variability analysis for the first time during Tai Chi and jogging. Continuous electrocardiographic monitoring over a period of 75 minutes was performed simultaneously in two healthy volunteers using the same type of equipment (medilog AR12 systems). Two healthy persons (both male, 49 years and 52 years, respectively), both hobby sportsmen, were monitored continuously during two resting periods before and after active sport and also during Tai Chi and jogging, respectively. Data acquisition was performed without any technical problems in both subjects. Poincaré plots of sequential R-R intervals (beat to beat variability) show two ellipses of different shape and magnitude. During resting periods blood pressure effects can be clearly seen in one subject (jogging). The same effects, however reduced, are obvious in the other volunteer during Tai Chi. The present investigations during Tai Chi and jogging highlight the potential value of heart rate and heart rate variability monitoring even under difficult conditions. The innovative kind of analysis helps to show how well the human body reacts to sport, stress and recovery.

  11. 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.

  12. 人工虫草复合液对无心跳模型大鼠离体肾的低温保护作用%Protective effect at low temperature of artificial cordyceps compound on isolated kidney from non-heart-beating rat models

    Institute of Scientific and Technical Information of China (English)

    戴晨; 王顺; 徐加波; 刘健

    2016-01-01

    背景:无心跳供体已成为近年来最有潜力的移植供体来源,为进一步改进供体保存液,在常规保存液高渗枸橼酸盐腺嘌呤液的基础上加入人工虫草制备人工虫草复合液,希望通过其抗氧化作用,减少供体损伤,提高供体质量。目的:探讨人工虫草复合液对无心跳大鼠离体肾的保存作用。方法:将39只SD大鼠毁损延髓,不进行体外呼吸循环支持,造成脑死亡诱导的无心跳模型后,随机等分为3组,人工虫草复合液组(n=15)、高渗枸橼酸盐腺嘌呤液组(n=15)和生理盐水组(n=9),分别用人工虫草复合液、高渗枸橼酸盐腺嘌呤液、生理盐水对离体肾脏进行4℃低温保存。结果与结论:与高渗枸橼酸盐腺嘌呤液组相比,人工虫草复合液组肾组织保存6和12 h后,形态损伤较轻,凋亡指数、丙二醛含量、Bax及Caspase-3表达水平下降,超氧化物歧化酶活力及Bcl-2表达水平上升;而保存24 h后,形态损伤程度接近,丙二醛含量下降,超氧化物歧化酶活力上升。提示人工虫草复合液对无心跳大鼠离体肾的抗氧化、抑制细胞凋亡方面保存效果优于高渗枸橼酸盐腺嘌呤液。%BACKGROUND:Non-heart beating donors have become the most promising source of donor in recent years. Tofurther improve donor preservation solution, on the basis of conventional storage solution hypertonic citrate adenine solution, artificial cordyceps was added to prepare artificial cordyceps compound solution. It is hoped to reduce donor injury and to elevate donor quality by antioxidation. OBJECTIVE: To investigate the preservation effect of artificial cordyceps compound solution on isolated renal from non-heart-beating rats. METHODS: Medulas of 39 Sprague-Dawley rats were injured. Withoutin vitro respiratory and circulatory supports, non-heart-beating models were established and randomly divided into three groups: artificial cordyceps

  13. Guided Tissue Regeneration in Heart Valve Replacement: From Preclinical Research to First-in-Human Trials

    Directory of Open Access Journals (Sweden)

    L. Iop

    2015-01-01

    Full Text Available Heart valve tissue-guided regeneration aims to offer a functional and viable alternative to current prosthetic replacements. Not requiring previous cell seeding and conditioning in bioreactors, such exceptional tissue engineering approach is a very fascinating translational regenerative strategy. After in vivo implantation, decellularized heart valve scaffolds drive their same repopulation by recipient’s cells for a prospective autologous-like tissue reconstruction, remodeling, and adaptation to the somatic growth of the patient. With such a viability, tissue-guided regenerated conduits can be delivered as off-the-shelf biodevices and possess all the potentialities for a long-lasting resolution of the dramatic inconvenience of heart valve diseases, both in children and in the elderly. A review on preclinical and clinical investigations of this therapeutic concept is provided with evaluation of the issues still to be well deliberated for an effective and safe in-human application.

  14. Guided tissue regeneration in heart valve replacement: from preclinical research to first-in-human trials.

    Science.gov (United States)

    Iop, L; Gerosa, G

    2015-01-01

    Heart valve tissue-guided regeneration aims to offer a functional and viable alternative to current prosthetic replacements. Not requiring previous cell seeding and conditioning in bioreactors, such exceptional tissue engineering approach is a very fascinating translational regenerative strategy. After in vivo implantation, decellularized heart valve scaffolds drive their same repopulation by recipient's cells for a prospective autologous-like tissue reconstruction, remodeling, and adaptation to the somatic growth of the patient. With such a viability, tissue-guided regenerated conduits can be delivered as off-the-shelf biodevices and possess all the potentialities for a long-lasting resolution of the dramatic inconvenience of heart valve diseases, both in children and in the elderly. A review on preclinical and clinical investigations of this therapeutic concept is provided with evaluation of the issues still to be well deliberated for an effective and safe in-human application.

  15. Transmural expression of ion channels and transporters in human nondiseased and end-stage failing hearts

    DEFF Research Database (Denmark)

    Soltysinska, Ewa; Olesen, Søren-Peter; Christ, Torsten

    2009-01-01

    The cardiac action potential is primarily shaped by the orchestrated function of several different types of ion channels and transporters. One of the regional differences believed to play a major role in the progression and stability of the action potential is the transmural gradient of electrical...... activity across the ventricular wall. An altered balance in the ionic currents across the free wall is assumed to be a substrate for arrhythmia. A large fraction of patients with heart failure experience ventricular arrhythmia. However, the underlying substrate of these functional changes is not well......-established as expression analyses of human heart failure (HF) are sparse. We have investigated steady-state RNA levels by quantitative polymerase chain reaction of ion channels, transporters, connexin 43, and miR-1 in 11 end-stage HF and seven nonfailing (NF) hearts. The quantifications were performed on endo-, mid...

  16. Na+,K+-ATPase concentration in rodent and human heart and skeletal muscle

    DEFF Research Database (Denmark)

    Kjeldsen, K; Bjerregaard, P; Richter, Erik

    1988-01-01

    rats, cardiomyopathic hamsters, and human subjects. These methods have earlier been shown to quantify the Na+,K+-ATPase concentration in muscle tissue with high accuracy. When rats were swim trained for six weeks the heart ventricular muscle Na+,K+-ATPase concentration was increased by 20% (p less than......To investigate whether the sodium-potassium pump or Na+,K+-ATPase concentration in muscles is related to the capacity for muscle performance, the 3H-ouabain binding site concentration or 3-O-methylflourescein phosphatase activity was determined in samples of heart ventricular muscles from trained...... was increased by up to 46% (p less than 0.001) and decreased by up to 30% (p less than 0.005) after training and immobilisation respectively. Cardiomyopathic hamsters showed a reduction of 33% (p less than 0.005) in the heart ventricular Na+,K+-ATPase concentration compared with normal hamsters. This decrease...

  17. Nocturnal variations in peripheral blood flow, systemic blood pressure, and heart rate in humans

    DEFF Research Database (Denmark)

    Sindrup, J H; Kastrup, J; Christensen, H

    1991-01-01

    was associated with a 30-40% increase in blood flow rate and a highly significant decrease in mean arterial blood pressure and heart rate (P less than 0.001 for all). Approximately 100 min after the subjects went to sleep an additional blood flow rate increment (mean 56%) and a simultaneous significant decrease......Subcutaneous adipose tissue blood flow rate, together with systemic arterial blood pressure and heart rate under ambulatory conditions, was measured in the lower legs of 15 normal human subjects for 12-20 h. The 133Xe-washout technique, portable CdTe(Cl) detectors, and a portable data storage unit...... were used for measurement of blood flow rates. An automatic portable blood pressure recorder and processor unit was used for measurement of systolic blood pressure, diastolic blood pressure, and heart rate every 15 min. The change from upright to supine position at the beginning of the night period...

  18. Fractionated magnetic-resonance elastography on the human heart; Fraktionierte Magnetresonanzelastographie am menschlichen Herzen

    Energy Technology Data Exchange (ETDEWEB)

    Rump, Jens

    2008-07-28

    Imaging techniques, including magnetic resonance imaging, belong to the most important tools in modern medical diagnostics. Another diagnostic aid is palpation, which is suitable for the qualitative characterization of pathological changes in organs near the surface. Magnetic resonance elastography (MRE) is a combination of these techniques. In principle, MRE uses motionsensitive MR-imaging to depict tissue deformation caused by externally induced shear waves. The type of deformation supply useful information about the elasticity of the tissue. Cardiac disorders are among the most common diseases. The goal of this study was to develop a method of applying in-vivo MRE to the human heart. The development of the mechanical stimulus, ultimately resulting in the introduction of an audio speaker as the source of vibration, provided the necessary means to introduce vibrations into inner organs. A crucial factor in applying MRE to the heart is the speed of the recording, which led to the development of 'fractional MRE'. The currently conventional fast heart imaging techniques were used as a starting point. The use of an unbalanced phase preparation gradient in the balanced steady-state imaging technique resulted in an improved phase-to-noise ratio. Along with the spoiled steady-state MRE imaging technique, initial MRE-studies on the human heart were performed. For the first time, externally induced mechanical vibrations were successfully introduced into the heart and were detected using fractional MRE with a high temporal resolution. The modulation of the shear wave amplitudes observed in the myocard of 6 healthy subjects correlated with the phases of the cardiac cycle. The techniques and methods developed here are a step toward routine clinical application of MRE of the heart and indicate high potential in the area of early diagnosis of cardiac disease. (orig.)

  19. Can stem cells really regenerate the human heart? Use your noggin, dickkopf! Lessons from developmental biology.

    Science.gov (United States)

    Sommer, Paula

    2013-06-01

    The human heart is the first organ to develop and its development is fairly well characterised. In theory, the heart has the capacity to regenerate, as its cardiomyocytes may be capable of cell division and the adult heart contains a cardiac stem cell niche, presumably capable of differentiating into cardiomyocytes and other cardiac-associated cell types. However, as with most other organs, these mechanisms are not activated upon serious injury. Several experimental options to induce regeneration of the damaged heart tissue are available: activate the endogenous cardiomyocytes to divide, coax the endogenous population of stem cells to divide and differentiate, or add exogenous cell-based therapy to replace the lost cardiac tissue. This review is a summary of the recent research into all these avenues, discussing the reasons for the limited successes of clinical trials using stem cells after cardiac injury and explaining new advances in basic science. It concludes with a reiteration that chances of successful regeneration would be improved by understanding and implementing the basics of heart development and stem cell biology.

  20. Psychophysiological reactivity to auditory Binaural Beats stimulation in the alpha and theta EEG brain-wave frequency bands: A randomized, double–blind and placebo–controlled study in human healthy young adult subjects

    OpenAIRE

    Pfaff, Hans Uwe

    2014-01-01

    Tesis doctoral inédita leída en la Universidad Autónoma de Madrid, Facultad de Psicología, Departamento de Psicología Biológica y de la Salud. Fecha de lectura: 25-06-2014 Binaural beats are an acoustical illusion of the perception of a “virtual” third tone, fluctuating (i.e. beating) in its volume evoked by two carrier–sinusoids of same amplitudes, but slightly different frequencies f1 and f2, presented by stereo-headphones. Although this illusion was discovered as early as 1839 ...

  1. Monitoring nocturnal heart rate with bed sensor.

    Science.gov (United States)

    Migliorini, M; Kortelainen, J M; Pärkkä, J; Tenhunen, M; Himanen, S L; Bianchi, A M

    2014-01-01

    This article is part of the Focus Theme of Methods of Information in Medicine on "Biosignal Interpretation: Advanced Methods for Studying Cardiovascular and Respiratory Systems". The aim of this study is to assess the reliability of the estimated Nocturnal Heart Rate (HR), recorded through a bed sensor, compared with the one obtained from standard electrocardiography (ECG). Twenty-eight sleep deprived patients were recorded for one night each through matrix of piezoelectric sensors, integrated into the mattress, through polysomnography (PSG) simultaneously. The two recording methods have been compared in terms of signal quality and differences in heart beat detection. On average, coverage of 92.7% of the total sleep time was obtained for the bed sensor, testifying the good quality of the recordings. The average beat-to-beat error of the inter-beat intervals was 1.06%. These results suggest a good overall signal quality, however, considering fast heart rates (HR > 100 bpm), performances were worse: in fact, the sensitivity in the heart beat detection was 28.4% while the false positive rate was 3.8% which means that a large amount of fast beats were not detected. The accuracy of the measurements made using the bed sensor has less than 10% of failure rate especially in periods with HR lower than 70 bpm. For fast heart beats the uncertainty increases. This can be explained by the change in morphology of the bed sensor signal in correspondence of a higher HR.

  2. Frequency Structure of Heart Rate Variability

    OpenAIRE

    MUKHIN, V.

    2008-01-01

    Factor structure of heart rate periodogram has been detected with factor analysis. The results showed that there are at least four periodical phenomena of HRV. Two of them have not been discovered and physiologically explained yet. Their frequency ranges are 0.21 to 0.31 1/beat with the peak at 0.26 1/beat and 0.25 to 0.5 1/beat with the peak 0.35 1/beat. Despite of differences of the peak frequencies the frequency rages of the factors are overlapped. Therefore, power of spectral density with...

  3. Successful Orthotopic Heart Transplantation and Immunosuppressive Management in 2 Human Immunodeficiency Virus-Seropositive Patients.

    Science.gov (United States)

    Conte, Antonio Hernandez; Kittleson, Michelle M; Dilibero, Deanna; Hardy, W David; Kobashigawa, Jon A; Esmailian, Fardad

    2016-02-01

    Few orthotopic heart transplantations have been performed in patients infected with the human immunodeficiency virus since the first such case was reported in 2001. Since that time, advances in highly active antiretroviral therapy have resulted in potent and durable suppression of the causative human immunodeficiency virus-accompanied by robust immune reconstitution, reversal of previous immunodeficiency, a marked decrease in opportunistic and other infections, and near-normal long-term survival. Although human immunodeficiency virus infection is not an absolute contraindication, few centers in the United States and Canada have performed heart transplantations in this patient population; these patients have been de facto excluded from this procedure in North America. Re-evaluation of the reasons for excluding these patients from cardiac transplantation is warranted in light of such significant advances in antiretroviral therapy. This case report documents successful orthotopic heart transplantation in 2 patients infected with human immunodeficiency virus, and we describe their antiretroviral therapy and immunosuppressive management challenges. Both patients were doing well without sequelae 43 and 38 months after transplantation.

  4. Successful Orthotopic Heart Transplantation and Immunosuppressive Management in 2 Human Immunodeficiency Virus–Seropositive Patients

    Science.gov (United States)

    Kittleson, Michelle M.; Dilibero, Deanna; Hardy, W. David; Kobashigawa, Jon A.; Esmailian, Fardad

    2016-01-01

    Few orthotopic heart transplantations have been performed in patients infected with the human immunodeficiency virus since the first such case was reported in 2001. Since that time, advances in highly active antiretroviral therapy have resulted in potent and durable suppression of the causative human immunodeficiency virus—accompanied by robust immune reconstitution, reversal of previous immunodeficiency, a marked decrease in opportunistic and other infections, and near-normal long-term survival. Although human immunodeficiency virus infection is not an absolute contraindication, few centers in the United States and Canada have performed heart transplantations in this patient population; these patients have been de facto excluded from this procedure in North America. Re-evaluation of the reasons for excluding these patients from cardiac transplantation is warranted in light of such significant advances in antiretroviral therapy. This case report documents successful orthotopic heart transplantation in 2 patients infected with human immunodeficiency virus, and we describe their antiretroviral therapy and immunosuppressive management challenges. Both patients were doing well without sequelae 43 and 38 months after transplantation. PMID:27047290

  5. Activation of calcineurin in human failing heart ventricle by endothelin-1, angiotensin II and urotensin II.

    Science.gov (United States)

    Li, Joan; Wang, Jianchun; Russell, Fraser D; Molenaar, Peter

    2005-06-01

    1 The calcineurin (CaN) enzyme-transcriptional pathway is critically involved in hypertrophy of heart muscle in some animal models. Currently there is no information concerning the regulation of CaN activation by endogenous agonists in human heart. 2 Human right ventricular trabeculae from explanted human (14 male/2 female) failing hearts were set up in a tissue bath and electrically paced at 1 Hz and incubated with or without 100 nM endothelin-1 (ET-1), 10 M, angiotensin-II (Ang II) or 20 nM human urotensin-II (hUII) for 30 min. Tissues from four patients were incubated with 200 nM tacrolimus (FK506) for 30 min and then incubated in the presence or absence of ET-1 for a further 30 min. 3 ET-1 increased contractile force in all 13 patients (P0.1). FK506 had no effect on contractile force (P=0.12). 4 ET-1, Ang II and hUII increased calcineurin activity by 32, 71 and 15%, respectively, while FK506 reduced activity by 34%. ET-1 in the presence of FK506 did not restore calcineurin activity (P=0.1). 5 There was no relationship between basal CaN activity and expression levels in the right ventricle. Increased levels of free phosphate were detected in ventricular homogenates that were incubated with PKC(epsilon) compared to samples incubated without PKC(epsilon). 6 Endogenous cardiostimulants which activate G(alpha)q-coupled receptors increase the activity of calcineurin in human heart following acute (30 min) exposure. PKC may contribute to this effect by increasing levels of phosphorylated calcineurin substrate.

  6. A study on the physical fitness index, heart rate and blood pressure in different phases of lunar month on male human subjects

    Science.gov (United States)

    Chakraborty, Ujjwal; Ghosh, Tusharkanti

    2013-09-01

    The gravitational pull of the moon on the earth is not the same in all phases of the lunar month, i.e. new moon (NM), first quarter (FQ), full moon (FM) and third quarter (TQ), and as a result the amplitude of tide differs in different phases. The gravitational pull of the moon may have effects on the fluid compartments of the human body and hence the cardiovascular system may be affected differentially in the different phases of the lunar month. In the present study resting heart rate (HR) and blood pressure (BP), physical fitness index (PFI), peak HR and BP immediately after step test, and recovery HR and BP after step test were measured during different phases of the lunar month in 76 male university students (age 23.7 ± 1.7 years). At rest, both systolic and mean arterial BP were ˜5 mmHg lower in NM and FM compared to FQ and TQ, but resting HR was not significantly different between phases. Further, peak HR and peak systolic BP after step test were lower (˜4 beat/min and ˜5 mmHg, respectively) in NM and FM compared to FQ and TQ. PFI was also higher (˜5) in NM and FM compared to FQ and TQ. Recovery of HR after step test was quicker in NM and FM compared to that of FQ and TQ. It appears from this study that gravitational pull of the moon may affect the cardiovascular functions of the human body. Moreover, the physical efficiency of humans is increased in NM and FM due to these altered cardiovascular regulations.

  7. A study on the physical fitness index, heart rate and blood pressure in different phases of lunar month on male human subjects.

    Science.gov (United States)

    Chakraborty, Ujjwal; Ghosh, Tusharkanti

    2013-09-01

    The gravitational pull of the moon on the earth is not the same in all phases of the lunar month, i.e. new moon (NM), first quarter (FQ), full moon (FM) and third quarter (TQ), and as a result the amplitude of tide differs in different phases. The gravitational pull of the moon may have effects on the fluid compartments of the human body and hence the cardiovascular system may be affected differentially in the different phases of the lunar month. In the present study resting heart rate (HR) and blood pressure (BP), physical fitness index (PFI), peak HR and BP immediately after step test, and recovery HR and BP after step test were measured during different phases of the lunar month in 76 male university students (age 23.7 ± 1.7 years). At rest, both systolic and mean arterial BP were ∼5 mmHg lower in NM and FM compared to FQ and TQ, but resting HR was not significantly different between phases. Further, peak HR and peak systolic BP after step test were lower (∼4 beat/min and ∼5 mmHg, respectively) in NM and FM compared to FQ and TQ. PFI was also higher (∼5) in NM and FM compared to FQ and TQ. Recovery of HR after step test was quicker in NM and FM compared to that of FQ and TQ. It appears from this study that gravitational pull of the moon may affect the cardiovascular functions of the human body. Moreover, the physical efficiency of humans is increased in NM and FM due to these altered cardiovascular regulations.

  8. Electrical Brain Responses to Beat Irregularities in Two Cases of Beat Deafness.

    Science.gov (United States)

    Mathias, Brian; Lidji, Pascale; Honing, Henkjan; Palmer, Caroline; Peretz, Isabelle

    2016-01-01

    Beat deafness, a recently documented form of congenital amusia, provides a unique window into functional specialization of neural circuitry for the processing of musical stimuli: Beat-deaf individuals exhibit deficits that are specific to the detection of a regular beat in music and the ability to move along with a beat. Studies on the neural underpinnings of beat processing in the general population suggest that the auditory system is capable of pre-attentively generating a predictive model of upcoming sounds in a rhythmic pattern, subserved largely within auditory cortex and reflected in mismatch negativity (MMN) and P3 event-related potential (ERP) components. The current study examined these neural correlates of beat perception in two beat-deaf individuals, Mathieu and Marjorie, and a group of control participants under conditions in which auditory stimuli were either attended or ignored. Compared to control participants, Mathieu demonstrated reduced behavioral sensitivity to beat omissions in metrical patterns, and Marjorie showed a bias to identify irregular patterns as regular. ERP responses to beat omissions reveal an intact pre-attentive system for processing beat irregularities in cases of beat deafness, reflected in the MMN component, and provide partial support for abnormalities in later cognitive stages of beat processing, reflected in an unreliable P3b component exhibited by Mathieu-but not Marjorie-compared to control participants. P3 abnormalities observed in the current study resemble P3 abnormalities exhibited by individuals with pitch-based amusia, and are consistent with attention or auditory-motor coupling accounts of deficits in beat perception.

  9. Electrical brain responses to beat irregularities in two cases of beat deafness

    Directory of Open Access Journals (Sweden)

    Brian eMathias

    2016-02-01

    Full Text Available Beat deafness, a recently documented form of congenital amusia, provides a unique window into functional specialization of neural circuitry for the processing of musical stimuli: Beat-deaf individuals exhibit deficits that are specific to the detection of a regular beat in music and the ability to move along with a beat. Studies on the neural underpinnings of beat processing in the general population suggest that the auditory system is capable of pre-attentively generating a predictive model of upcoming sounds in a rhythmic pattern, subserved largely within auditory cortex and reflected in mismatch negativity (MMN and P3 event-related potential (ERP components. The current study examined these neural correlates of beat perception in two beat-deaf individuals, Mathieu and Marjorie, and a group of control participants under conditions in which auditory stimuli were either attended or ignored. Compared to control participants, Mathieu demonstrated reduced behavioral sensitivity to beat omissions in metrical patterns, and Marjorie showed a bias to identify irregular patterns as regular. ERP responses to beat omissions reveal an intact pre-attentive system for processing beat irregularities in cases of beat deafness, reflected in the MMN component, and provide partial support for abnormalities in later cognitive stages of beat processing, reflected in an unreliable P3b component exhibited by Mathieu – but not Marjorie – compared to control participants. P3 abnormalities observed in the current study resemble P3 abnormalities exhibited by individuals with pitch-based amusia, and are consistent with attention or auditory-motor coupling accounts of deficits in beat perception.

  10. Shifts in the myosin heavy chain isozymes in the mouse heart result in increased energy efficiency

    Science.gov (United States)

    Hoyer, Kirsten; Krenz, Maike; Robbins, Jeffrey; Ingwall, Joanne S.

    2007-01-01

    Cardiac-specific transgenesis in the mouse is widely used to study the basic biology and chemistry of the heart and to model human cardiovascular disease. A fundamental difference between mouse and human hearts is the background motor protein: mouse hearts contain predominantly the αα-myosin heavy chain (MyHC) isozyme while human hearts contain predominantly the ββ-MyHC isozyme. Although the intrinsic differences in mechanical and enzymatic properties of the αα- and ββ-MyHC molecules are well known, the consequences of isozyme shifts on energetic of the intact beating heart remain unknown. Therefore, we compared the free energy of ATP hydrolysis (|ΔG~ATP|) determined by 31P NMR spectroscopy in isolated perfused littermate mouse hearts containing the same amount of myosin comprised of either >95% αα-MyHC or ~83% ββ-MyHC. |ΔG~ATP| was ~2 kJ mol−1 higher in the ββ-MyHC hearts at all workloads. Furthermore, upon inotropic challenge, hearts containing predominantly ββ-MyHC hearts increased developed pressure more than αα-MyHC hearts whereas heart rate increased more in αα-MyHC hearts. Thus, hearts containing predominantly the ββ-MyHC isozyme are more energy efficient than αα-MyHC hearts. We suggest that these fundamental differences in the motor protein energy efficiency at the whole heart level should be considered when interpreting results using mouse-based cardiovascular modeling of normal and diseased human heart. PMID:17054980

  11. 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.

  12. Selective neuronal entrainment to the beat and meter embedded in a musical rhythm.

    Science.gov (United States)

    Nozaradan, Sylvie; Peretz, Isabelle; Mouraux, André

    2012-12-05

    Fundamental to the experience of music, beat and meter perception refers to the perception of periodicities while listening to music occurring within the frequency range of musical tempo. Here, we explored the spontaneous building of beat and meter hypothesized to emerge from the selective entrainment of neuronal populations at beat and meter frequencies. The electroencephalogram (EEG) was recorded while human participants listened to rhythms consisting of short sounds alternating with silences to induce a spontaneous perception of beat and meter. We found that the rhythmic stimuli elicited multiple steady state-evoked potentials (SS-EPs) observed in the EEG spectrum at frequencies corresponding to the rhythmic pattern envelope. Most importantly, the amplitude of the SS-EPs obtained at beat and meter frequencies were selectively enhanced even though the acoustic energy was not necessarily predominant at these frequencies. Furthermore, accelerating the tempo of the rhythmic stimuli so as to move away from the range of frequencies at which beats are usually perceived impaired the selective enhancement of SS-EPs at these frequencies. The observation that beat- and meter-related SS-EPs are selectively enhanced at frequencies compatible with beat and meter perception indicates that these responses do not merely reflect the physical structure of the sound envelope but, instead, reflect the spontaneous emergence of an internal representation of beat, possibly through a mechanism of selective neuronal entrainment within a resonance frequency range. Taken together, these results suggest that musical rhythms constitute a unique context to gain insight on general mechanisms of entrainment, from the neuronal level to individual level.

  13. Changes in the organization of excitation-contraction coupling structures in failing human heart.

    Directory of Open Access Journals (Sweden)

    David J Crossman

    Full Text Available BACKGROUND: The cardiac myocyte t-tubular system ensures rapid, uniform cell activation and several experimental lines of evidence suggest changes in the t-tubular system and associated excitation-contraction coupling proteins may occur in heart failure. METHODS AND RESULTS: The organization of t-tubules, L-type calcium channels (DHPRs, ryanodine receptors (RyRs and contractile machinery were examined in fixed ventricular tissue samples from both normal and failing hearts (idiopathic (non-ischemic dilated cardiomyopathy using high resolution fluorescent imaging. Wheat germ agglutinin (WGA, Na-Ca exchanger, DHPR and caveolin-3 labels revealed a shift from a predominantly transverse orientation to oblique and axial directions in failing myocytes. In failure, dilation of peripheral t-tubules occurred and a change in the extent of protein glycosylation was evident. There was no change in the fractional area occupied by myofilaments (labeled with phalloidin but there was a small reduction in the number of RyR clusters per unit area. The general relationship between DHPRs and RyR was not changed and RyR labeling overlapped with 51±3% of DHPR labeling in normal hearts. In longitudinal (but not transverse sections there was an ∼30% reduction in the degree of colocalization between DHPRs and RyRs as measured by Pearson's correlation coefficient in failing hearts. CONCLUSIONS: The results show that extensive remodelling of the t-tubular network and associated excitation-contraction coupling proteins occurs in failing human heart. These changes may contribute to abnormal calcium handling in heart failure. The general organization of the t-system and changes observed in failure samples have subtle differences to some animal models although the general direction of changes are generally similar.

  14. Improvement of Heart Failure by Human Amniotic Mesenchymal Stromal Cell Transplantation in Rats

    Directory of Open Access Journals (Sweden)

    Seyed Mohammad Taghi Razavi Tousi

    2016-11-01

    Full Text Available Background: Recently, stem cells have been considered for the treatment of heart diseases, but no marked improvement has been recorded. This is the first study to examine the functional and histological effects of the transplantation of human amniotic mesenchymal stromal cells (hAMSCs in rats with heart failure (HF.Methods: This study was conducted in the years 2014 and 2015. 35 male Wistar rats were randomly assigned into 5 equal experimental groups (7 rats each as 1- Control 2- Heart Failure (HF 3- Sham 4- Culture media 5- Stem Cell Transplantation (SCT. Heart failure was induced using 170 mg/kg/d of isoproterenol subcutaneously injection in 4 consecutive days. The failure confirmed by the rat cardiac echocardiography on day 28. In SCT group, 3×106 cells in 150 µl of culture media were transplanted to the myocardium. At the end, echocardiographic and hemodynamic parameters together with histological evaluation were done.Results: Echocardiography results showed that cardiac ejection fraction in HF group increased from 58/73 ± 9% to 81/25 ± 6/05% in SCT group (p value < 0.001. Fraction shortening in HF group was increased from 27/53 ± 8/58% into 45/55 ± 6/91% in SCT group (p value < 0.001. Furthermore, hAMSCs therapy significantly improved mean diastolic blood pressure, mean arterial pressure, left ventricular systolic pressure, rate pressure product, and left ventricular end-diastolic pressure compared to those in the HF group, with the values reaching the normal levels in the control group. A marked reduction in fibrosis tissue was also found in the SCT group (p value < 0.001 compared with the animals in the HF group.Conclusion: The transplantation of hAMSCs in rats with heart failure not only decreased the level of fibrosis but also conferred significant improvement in heart performance in terms of echocardiographic and hemodynamic parameters.

  15. Human Immunodeficiency Virus and Heart Failure in Low- and Middle-Income Countries.

    Science.gov (United States)

    Bloomfield, Gerald S; Alenezi, Fawaz; Barasa, Felix A; Lumsden, Rebecca; Mayosi, Bongani M; Velazquez, Eric J

    2015-08-01

    Successful combination therapy for human immunodeficiency virus (HIV) has transformed this disease from a short-lived infection with high mortality to a chronic disease associated with increasing life expectancy. This is true for high- as well as low- and middle-income countries. As a result of this increased life expectancy, people living with HIV are now at risk of developing other chronic diseases associated with aging. Heart failure has been common among people living with HIV in the eras of pre- and post- availability of antiretroviral therapy; however, our current understanding of the pathogenesis and approaches to management have not been systematically addressed. HIV may cause heart failure through direct (e.g., viral replication, mitochondrial dysfunction, cardiac autoimmunity, autonomic dysfunction) and indirect (e.g., opportunistic infections, antiretroviral therapy, alcohol abuse, micronutrient deficiency, tobacco use) pathways. In low- and middle-income countries, 2 large observational studies have recently reported clinical characteristics and outcomes in these patients. HIV-associated heart failure remains a common cardiac diagnosis in people living with heart failure, yet a unifying set of diagnostic criteria is lacking. Treatment patterns for heart failure fall short of society guidelines. Although there may be promise in cardiac glycosides for treating heart failure in people living with HIV, clinical studies are needed to validate in vitro findings. Owing to the burden of HIV in low- and middle-income countries and the concurrent rise of traditional cardiovascular risk factors, strategic and concerted efforts in this area are likely to impact the care of people living with HIV around the globe. Copyright © 2015 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

  16. 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.

  17. Genome-wide identification of expression quantitative trait loci (eQTLs in human heart.

    Directory of Open Access Journals (Sweden)

    Tamara T Koopmann

    Full Text Available In recent years genome-wide association studies (GWAS have uncovered numerous chromosomal loci associated with various electrocardiographic traits and cardiac arrhythmia predisposition. A considerable fraction of these loci lie within inter-genic regions. The underlying trait-associated variants likely reside in regulatory regions and exert their effect by modulating gene expression. Hence, the key to unraveling the molecular mechanisms underlying these cardiac traits is to interrogate variants for association with differential transcript abundance by expression quantitative trait locus (eQTL analysis. In this study we conducted an eQTL analysis of human heart. For a total of 129 left ventricular samples that were collected from non-diseased human donor hearts, genome-wide transcript abundance and genotyping was determined using microarrays. Each of the 18,402 transcripts and 897,683 SNP genotypes that remained after pre-processing and stringent quality control were tested for eQTL effects. We identified 771 eQTLs, regulating 429 unique transcripts. Overlaying these eQTLs with cardiac GWAS loci identified novel candidates for studies aimed at elucidating the functional and transcriptional impact of these loci. Thus, this work provides for the first time a comprehensive eQTL map of human heart: a powerful and unique resource that enables systems genetics approaches for the study of cardiac traits.

  18. The role of n-3 polyunsaturated fatty acids in human heart failure.

    Science.gov (United States)

    Poudyal, Hemant; Brown, Lindsay

    2013-03-01

    n-3 polyunsaturated fatty acids (PUFA) have been proposed as potential treatments for human heart failure. The cardioprotective effects of n-3 PUFA are supported by extensive cell culture, animal and human studies. Animal studies with n-3 PUFA have shown marked improvements in many independent risk factors for heart failure, including obesity, type II diabetes, insulin resistance, hypertension and inflammation. However, the evidence from observational studies, randomised controlled trials and meta-analyses that these benefits on risk factors lead to improvements in the symptoms of heart failure in patients is much less convincing. Further, most studies have used marine n-3 PUFA; the role of the plant-derived PUFA, α-linolenic acid (ALA), is even less clear. This discontinuity of scientific evidence from animal to human studies suggests that future studies should focus on defining the optimal dosage range and the efficacy of n-3 PUFA compared to standard treatments using standardised study designs. Further studies on ALA would seem justified.

  19. Chromosomally integrated human herpesvirus 6 in heart failure: prevalence and treatment.

    Science.gov (United States)

    Kühl, Uwe; Lassner, Dirk; Wallaschek, Nina; Gross, Ulrich M; Krueger, Gerhard R F; Seeberg, Bettina; Kaufer, Benedikt B; Escher, Felicitas; Poller, Wolfgang; Schultheiss, Heinz-Peter

    2015-01-01

    Human herpesvirus 6 (HHV-6) A and B are two betaherpesviruses that are associated with many conditions including roseola, drug-induced hypersensitivity syndrome, limbic encephalitis, and myocarditis. HHV-6 is integrated in the germline [chromosomically integrated HHV-6 (ciHHV-6)] in ∼0.8% of the human population. To date, the prevalence, species distribution, and treatment responses of ciHHV-6 are unknown for cardiac patients. We determined the prevalence of HHV-6 and ciHHV-6 genotypes in 1656 endomyocardial biopsies of patients with persisting unexplained symptoms of heart failure. Infection of cardiac tissue was identified by nested PCR, electron microscopy, and immunohistochemistry. Virus load and mRNA levels were followed in ciHHV-6 patients treated with ganciclovir. HHV-6 was detected in 273 of 1656 cardiac tissues (16.5%; HHV-6B, 98.2%, HHV-6A, 1.8%) by PCR. Nineteen of the 1656 patients (1.1%) presented with persistently high HHV-6 copy numbers indicative of ciHHV-6. Sequencing confirmed ciHHV-6A in seven patients (36.8%) which was considerably higher than detected in non-ciHHV-6 patients. Inheritance was demonstrated in three selected families, confirming ciHHV-6 chromosomal integration by PCR and fluorescence in situ hybridization. HHV-6 reactivation and chromosomal integration were confirmed in peripheral blood mononuclear cells and heart tissue. Virus particles were identified in degenerating myocytes and interstitial cells. Antiviral treatment abolished viral mRNA and ameliorated cardiac symptoms. Virus replication in cardiac tissue of ciHHV-6 heart failure patients suggests that ciHHV-6 reactivation causes persistence of unexplained heart failure symptoms. We demonstrated that antiviral treatment, effective in decreasing viral transcripts and clinical complaints of cardiomyopathies, is a new therapeutic option for ciHHV-6-associated diseases. © 2014 The Authors. European Journal of Heart Failure © 2014 European Society of Cardiology.

  20. High Blood Pressure: Keep the Beat Recipes

    Science.gov (United States)

    ... of this page please turn Javascript on. Feature: High Blood Pressure Keep the Beat Recipes Past Issues / Fall 2011 ... 65 million American adults—one in three—with high blood pressure, you have probably heard the advice, "watch your ...

  1. The impact of binaural beats on creativity

    National Research Council Canada - National Science Library

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

    2013-01-01

    .... 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...

  2. 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 %.

  3. Organization of ventricular fibrillation in the human heart: experiments and models.

    Science.gov (United States)

    ten Tusscher, K H W J; Mourad, A; Nash, M P; Clayton, R H; Bradley, C P; Paterson, D J; Hren, R; Hayward, M; Panfilov, A V; Taggart, P

    2009-05-01

    Sudden cardiac death is a major health problem in the industrialized world. The lethal event is typically ventricular fibrillation (VF), during which the co-ordinated regular contraction of the heart is overthrown by a state of mechanical and electrical anarchy. Understanding the excitation patterns that sustain VF is important in order to identify potential therapeutic targets. In this paper, we studied the organization of human VF by combining clinical recordings of electrical excitation patterns on the epicardial surface during in vivo human VF with simulations of VF in an anatomically and electrophysiologically detailed computational model of the human ventricles. We find both in the computational studies and in the clinical recordings that epicardial surface excitation patterns during VF contain around six rotors. Based on results from the simulated three-dimensional excitation patterns during VF, which show that the total number of electrical sources is 1.4 +/- 0.12 times greater than the number of epicardial rotors, we estimate that the total number of sources present during clinically recorded VF is 9.0 +/- 2.6. This number is approximately fivefold fewer compared with that observed during VF in dog and pig hearts, which are of comparable size to human hearts. We explain this difference by considering differences in action potential duration dynamics across these species. The simpler spatial organization of human VF has important implications for treatment and prevention of this dangerous arrhythmia. Moreover, our findings underline the need for integrated research, in which human-based clinical and computational studies complement animal research.

  4. Human Cardiac Tissue Engineering: From Pluripotent Stem Cells to Heart Repair

    Science.gov (United States)

    Jackman, Christopher P.; Shadrin, Ilya Y.; Carlson, Aaron L.; Bursac, Nenad

    2014-01-01

    Engineered cardiac tissues hold great promise for use in drug and toxicology screening, in vitro studies of human physiology and disease, and as transplantable tissue grafts for myocardial repair. In this review, we discuss recent progress in cell-based therapy and functional tissue engineering using pluripotent stem cell-derived cardiomyocytes and we describe methods for delivery of cells into the injured heart. While significant hurdles remain, notable advances have been made in the methods to derive large numbers of pure human cardiomyocytes, mature their phenotype, and produce and implant functional cardiac tissues, bringing the field a step closer to widespread in vitro and in vivo applications. PMID:25599018

  5. Heart rate variability and heart rate recovery as prognostic factors

    OpenAIRE

    GRAD, COSMIN

    2015-01-01

    Background and aim Heart rate (HR) can appear static and regular at rest, during exercise or recovery after exercise. However, HR is constantly adjusted due to factors such as breathing, blood pressure control, thermoregulation and the renin-angiotensin system, leading to a more dynamic response that can be quantified using HRV (heart rate variability). HRV is defined as the deviation in time between successive normal heart beat and is a noninvasive method to measure the total variation in a ...

  6. Heart Rate Monitors

    Science.gov (United States)

    1990-01-01

    Under a NASA grant, Dr. Robert M. Davis and Dr. William M. Portnoy came up with a new type of electrocardiographic electrode that would enable long term use on astronauts. Their invention was an insulated capacitive electrode constructed of a thin dielectric film. NASA subsequently licensed the electrode technology to Richard Charnitski, inventor of the VersaClimber, who founded Heart Rate, Inc., to further develop and manufacture personal heart monitors and to produce exercise machines using the technology for the physical fitness, medical and home markets. Same technology is on both the Home and Institutional Model VersaClimbers. On the Home Model an infrared heart beat transmitter is worn under exercise clothing. Transmitted heart rate is used to control the work intensity on the VersaClimber using the heart rate as the speedometer of the exercise. This offers advantages to a full range of users from the cardiac rehab patient to the high level physical conditioning of elite athletes. The company manufactures and markets five models of the 1*2*3 HEART RATE monitors that are used wherever people exercise to accurately monitor their heart rate. Company is developing a talking heart rate monitor that works with portable headset radios. A version of the heart beat transmitter will be available to the manufacturers of other aerobic exercise machines.

  7. [Heart rhythm in humans with different processing levels of acoustic information].

    Science.gov (United States)

    Makarenko, M V; Lyzohub, V S; Iukhymenko, L I; Khomenko, S M

    2011-01-01

    The peculiarities of the heart rhythm regulation were investigated in humans during the processing of acoustic information. Statistically significant differences were found in individuals with different levels of auditory-motor reactions according to the heart rhythm characteristics. Individuals with the high level of reactions were characterized by significantly lower total power spectrum (TP=1276.2 ms2), by the power spectrum of high (HL=280.1 ms12) and very low frequencies (VLF-469.8 ms2), as well as by low indexes of standard deviation of R-R intervals (SDNN=37.4 ms), when compared with the persons with the low level of reactions (5248.8; 866.7; 1937.0; 69.8 ms2). The correlation analysis confirmed the dif- ferences between the groups ol persons with adtierent number of processed information and variable (r=0.41, P<0.05) and spectral characteristics of heart rate (r=-0.49--0.56, P<0.05). Different strategies of activation of non-specific brain systems in formation of psycho-physiological reactions and participation of heart rhythm regulatory mechanisms in vegetative support of auditory information processing are discussed.

  8. Impact of space weather on human heart rate during the years 2011-2013

    Science.gov (United States)

    Galata, E.; Ioannidou, S.; Papailiou, M.; Mavromichalaki, H.; Paravolidakis, K.; Kouremeti, M.; Rentifis, L.; Simantirakis, E.; Trachanas, K.

    2017-08-01

    During the last years a possible link between different levels of solar and geomagnetic disturbances and human physiological parameters is suggested by several published studies. In this work the examination of the potential association between heart rate variations and specific space weather activities was performed. A total of 482 individuals treated at Hippocratio General Hospital in Athens, the Cardiology clinics of Nikaia General Hospital in Piraeus and the Heraklion University Hospital in Crete, Greece, were assessed from July 2011 to April 2013. The heart rate of the individuals was recorded by a Holter monitor on a n hourly basis, while the hourly variations of the cosmic ray intensity measured by the Neutron Monitor Station of the Athens University and of the geomagnetic index Dst provided by the Kyoto Observatory were used. The ANalysis Of VAriance (ANOVA) and the Multiple Linear Regression analysis were used for analysis of these data. A statistically significant effect of both cosmic rays and geomagnetic activity on heart rate was observed, which may indicate that changes in space weather could be linked to heart rate variations.

  9. 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.

  10. Human heart failure with preserved ejection versus feline cardiomyopathy: what can we learn from both veterinary and human medicine?

    Science.gov (United States)

    Prat, Valentine; Rozec, Bertrand; Gauthier, Chantal; Lauzier, Benjamin

    2017-08-14

    Cardiovascular affections are a growing health burden in human populations. Recent advances in cardiology have improved treatments and outcomes for myocardial infarction and arrhythmias, but other conditions still remain poorly understood. To date, the classical approach to study cardiovascular diseases involves rodent models, despite their strong differences with human cardiac physiology. In this context, this review will focus on the common traits between human and feline cardiac diseases, namely heart failure with preserved ejection fraction and feline cardiomyopathies, respectively. These two affections share similar pathological patterns and epidemiological characteristics. An improved knowledge would be of interest for both human and feline patients and could lead to the establishment of a more accurate treatment and therapeutic strategy for medical doctors and veterinary practitioners.

  11. 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

  12. Heart rates during competitive orienteering.

    OpenAIRE

    Bird, S R; Bailey, R.; Lewis, J.

    1993-01-01

    This study investigated the heart rate profiles of 16 experienced, competitive orienteers (aged 15-62 years) during three competitive events. Each competitor was assessed over three different types of course which were classified as: fast run (FR), slow run (SR) and highly physical (HP). The results showed that all subjects recorded heart rates that were between 140 and 180 beats min-1 for the majority of each event (irrespective of age or course type). The heart rate data indicated that the ...

  13. Observations and modeling of deterministic properties of human heart rate variability

    Indian Academy of Sciences (India)

    J J Zebrowski; R Baranowski

    2005-04-01

    Simple models show that in Type-I intermittency a characteristic U-shaped probability distribution is obtained for the laminar phase length. The laminar phase length distribution characteristic for Type-I intermittency may be obtained in human heart rate variability data for some cases of pathology. The heart and its regulatory systems are presumed to be both noisy and non-stationary. Although the effect of additive noise on the laminar phase distribution in Type-I intermittency is well-known, the effect of neither multiplicative noise nor non-stationarity have been studied. We first discuss the properties of two classes of models of Type-I intermittency: (a) the control parameter of the logistic map is changed dichotomously from a value within the intermittency range to just below the bifurcation point and back; (b) the control parameter is changed randomly within the same parameter range as in the model class (a). We show that the properties of both models are different from those obtained for Type-I intermittency in the presence of additive noise. The two models help to explain some of the features seen in the intermittency in human heart rate variability.

  14. Posttranslational modifications and dysfunction of mitochondrial enzymes in human heart failure.

    Science.gov (United States)

    Sheeran, Freya L; Pepe, Salvatore

    2016-08-01

    Deficiency of energy supply is a major complication contributing to the syndrome of heart failure (HF). Because the concurrent activity profile of mitochondrial bioenergetic enzymes has not been studied collectively in human HF, our aim was to examine the mitochondrial enzyme defects in left ventricular myocardium obtained from explanted end-stage failing hearts. Compared with nonfailing donor hearts, activity rates of complexes I and IV and the Krebs cycle enzymes isocitrate dehydrogenase, malate dehydrogenase, and aconitase were lower in HF, as determined spectrophotometrically. However, activity rates of complexes II and III and citrate synthase did not differ significantly between the two groups. Protein expression, determined by Western blotting, did not differ between the groups, implying posttranslational perturbation. In the face of diminished total glutathione and coenzyme Q10 levels, oxidative modification was explored as an underlying cause of enzyme dysfunction. Of the three oxidative modifications measured, protein carbonylation was increased significantly by 31% in HF (P transport chain and Krebs cycle enzymes without altered expression of protein levels. Augmented oxidative modification of crucial enzyme subunit structures implicates dysfunction due to diminished capacity for management of mitochondrial reactive oxygen species, thus contributing further to reduced bioenergetics in human HF.

  15. Differential DNA methylation correlates with differential expression of angiogenic factors in human heart failure.

    Directory of Open Access Journals (Sweden)

    Mehregan Movassagh

    Full Text Available Epigenetic mechanisms such as microRNA and histone modification are crucially responsible for dysregulated gene expression in heart failure. In contrast, the role of DNA methylation, another well-characterized epigenetic mark, is unknown. In order to examine whether human cardiomyopathy of different etiologies are connected by a unifying pattern of DNA methylation pattern, we undertook profiling with ischaemic and idiopathic end-stage cardiomyopathic left ventricular (LV explants from patients who had undergone cardiac transplantation compared to normal control. We performed a preliminary analysis using methylated-DNA immunoprecipitation-chip (MeDIP-chip, validated differential methylation loci by bisulfite-(BS PCR and high throughput sequencing, and identified 3 angiogenesis-related genetic loci that were differentially methylated. Using quantitative RT-PCR, we found that the expression of these genes differed significantly between CM hearts and normal control (p<0.01. Moreover, for each individual LV tissue, differential methylation showed a predicted correlation to differential expression of the corresponding gene. Thus, differential DNA methylation exists in human cardiomyopathy. In this series of heterogeneous cardiomyopathic LV explants, differential DNA methylation was found in at least 3 angiogenesis-related genes. While in other systems, changes in DNA methylation at specific genomic loci usually precede changes in the expression of corresponding genes, our current findings in cardiomyopathy merit further investigation to determine whether DNA methylation changes play a causative role in the progression of heart failure.

  16. The impact of human rhinovirus infection in pediatric patients undergoing heart surgery.

    Science.gov (United States)

    Delgado-Corcoran, Claudia; Witte, Madolin K; Ampofo, Krow; Castillo, Ramon; Bodily, Stephanie; Bratton, Susan L

    2014-12-01

    Human rhinovirus (HRV), the most common cause of upper respiratory infection in children, can present as bronchiolitis, pneumonia, or asthma exacerbations. The impact of HRV in infants and toddlers with congenital heart disease is poorly defined. A case-control study was performed to compare the clinical course for 19 young children with respiratory symptoms who tested positive for rhinovirus after heart surgery with that of 56 matched control subjects. The control subjects were matched by surgical repair, age, weight, and time of the year. Patients with known HRVs before surgery and control subjects with respiratory symptoms or positive test results for viruses were excluded from the study. Human rhinovirus infection was associated with more than a tenfold increase in the odds of noninvasive ventilation after extubation (odds ratio [OR] 11.45; 95 % confidence interval [CI] 3.97-38.67), a 12-fold increase in the probability of extubation failure (OR 12.84; 95 % CI 2.93-56.29), and increased use of pulmonary medications including bronchodilator and nitric oxide (p rhinovirus increases resource use and prolongs postoperative recovery after pediatric heart surgery. Surgery timing should be delayed for patients with rhinovirus if possible.

  17. An Integrated Simulation Tool for Modeling the Human Circulatory System

    Science.gov (United States)

    Asami, Ken'ichi; Kitamura, Tadashi

    This paper presents an integrated simulation of the circulatory system in physiological movement. The large circulatory system model includes principal organs and functional units in modules in which comprehensive physiological changes such as nerve reflexes, temperature regulation, acid/base balance, O2/CO2 balance, and exercise are simulated. A beat-by-beat heart model, in which the corresponding electrical circuit problems are solved by a numerical analytic method, enables calculation of pulsatile blood flow to the major organs. The integration of different perspectives on physiological changes makes this simulation model applicable for the microscopic evaluation of blood flow under various conditions in the human body.

  18. 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

    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. PMID:28467407

  19. Comparison of heart rate in the aquatic environment and on the land

    Directory of Open Access Journals (Sweden)

    Dan Thiel

    2016-12-01

    Full Text Available Background: The difference between atmospheric air and water can be described based on the chemical and physical properties. Difference between these properties demonstrably affects sport performance and cannot perform the same activity identically in water and on land. This is evident especially in terms of biomechanics of movement. Difference in density of the environment does not allow one to perform the movement in the same way. In addition biomechanics is compared environmental influence on the human body physiological in physical activity. Changes in heart rate is one of the physiological parameters that are being investigated. Objective: To determine whether the body submersion under water will have a significant impact on changes in resting heart rate compared to heart rate measured in the same position on the land. Methods: This is a quantitative study conducted by comparing the values of heart on the land and in the water of 30 athletes with experiences from water sports and swimming (age 23.7 ± 1.8 years. Heart rate was measured for five minutes in static position on the back (water = 26 cm, water temperature 30.4 ± 0.2° C, air temperature 23.4 ± 0.4° C. Parametric unpaired Student t-test have been used for calculation of statistical significance have (p = .05. Threshold for estimation of practical significance of heart rate variance have been established at ±3 beats per minute. Results: Results of parametric unpaired Student t-test did not indicate statistically significant differnce of resting heart rate in the water and on the land (p = .080-.925. Heart rate decreased at least 3 beats per minute in ten people, increased at least 3 beats per minute in seven people, or stayed in range of ±3 beats per minute in 13 people. Conclusions: Results showed that a water environment has not a statistically significant effect for changing the resting heart rate. We are not able to come with a clear trend of

  20. Rapid manufacturing techniques for the tissue engineering of human heart valves.

    Science.gov (United States)

    Lueders, Cora; Jastram, Ben; Hetzer, Roland; Schwandt, Hartmut

    2014-10-01

    Three-dimensional (3D) printing technologies have reached a level of quality that justifies considering rapid manufacturing for medical applications. Herein, we introduce a new approach using 3D printing to simplify and improve the fabrication of human heart valve scaffolds by tissue engineering (TE). Custom-made human heart valve scaffolds are to be fabricated on a selective laser-sintering 3D printer for subsequent seeding with vascular cells from human umbilical cords. The scaffolds will be produced from resorbable polymers that must feature a number of specific properties: the structure, i.e. particle granularity and shape, and thermic properties must be feasible for the printing process. They must be suitable for the cell-seeding process and at the same time should be resorbable. They must be applicable for implementation in the human body and flexible enough to support the full functionality of the valve. The research focuses mainly on the search for a suitable scaffold material that allows the implementation of both the printing process to produce the scaffolds and the cell-seeding process, while meeting all of the above requirements. Computer tomographic data from patients were transformed into a 3D data model suitable for the 3D printer. Our current activities involve various aspects of the printing process, material research and the implementation of the cell-seeding process. Different resorbable polymeric materials have been examined and used to fabricate heart valve scaffolds by rapid manufacturing. Human vascular cells attached to the scaffold surface should migrate additionally into the inner structure of the polymeric samples. The ultimate intention of our approach is to establish a heart valve fabrication process based on 3D rapid manufacturing and TE. Based on the computer tomographic data of a patient, a custom-made scaffold for a valve will be produced on a 3D printer and populated preferably by autologous cells. The long-term goal is to support

  1. Combined use of autogenic therapy and biofeedback in training effective control of heart rate by humans

    Science.gov (United States)

    Cowings, P. S.

    1977-01-01

    Experiments were performed on 24 men and women (aged 20-27 yr) in three equal groups who were taught to control their own heart rates by autogenic training and biofeedback under dark and sound-isolated conditions. Group I was parasympathetic dominant, group II was sympathetic dominant, and group III consisted of parasympathetic-dominant subjects and controls who received only biofeedback of their own heart rates. The results corroborate three hypotheses: (1) subjects with para-sympathetic-dominant autonomic profiles perform in a way that is both qualitatively and quantitatively different from subjects with sympathetic-dominant autonomic profiles; (2) tests of interindividual variability yield data relevant to individual performance in visceral learning tasks; and (3) the combined use of autogenic training, biofeedback, and verbal feedback is suitable for conditioning large stable autonomic responses in humans.

  2. The roadmap of WT1 protein expression in the human fetal heart.

    Science.gov (United States)

    Duim, Sjoerd N; Smits, Anke M; Kruithof, Boudewijn P T; Goumans, Marie-José

    2016-01-01

    The transcription factor Wilms' Tumor-1 (WT1) is essential for cardiac development. Deletion of Wt1 in mice results in disturbed epicardial and myocardial formation and lack of cardiac vasculature, causing embryonic lethality. Little is known about the role of WT1 in the human fetal heart. Therefore, as a first step, we analyzed the expression pattern of WT1 protein during human cardiac development from week 4 till week 20. WT1 expression was apparent in epicardial, endothelial and endocardial cells in a spatiotemporal manner. The expression of WT1 follows a pattern starting at the epicardium and extending towards the lumen of the heart, with differences in timing and expression levels between the atria and ventricles. The expression of WT1 in cardiac arterial endothelial cells reduces in time, whereas WT1 expression in the endothelial cells of cardiac veins and capillaries remains present at all stages studied. This study provides for the first time a detailed description of the expression of WT1 protein during human cardiac development, which indicates an important role for WT1 also in human cardiogenesis. Copyright © 2015 Elsevier Ltd. All rights reserved.

  3. Heart rate variability of human in hypoxic oxygen-argon environment

    Science.gov (United States)

    Khayrullina, Rezeda; Smoleevskiy, Alexandr; Bubeev, Yuri

    Human adaptive capacity, reliability and stability in extreme environments depend primarily on the individual resistance to stresses, includes both innate and acquired components. We have conducted studies in six healthy subjects - men aged between 24 to 42 years who psychophysiological indicators acterizing the severity of stress reactions studied directly during an emergency situation, before and after it. The subjects were in a hypoxic oxygen-argon atmosphere 10 days. Cardiovascular system is one of the first to respond to stressful reaction. The method of heart rate variability (HRV) allows us to estimate balance of sympathetic and parasympathetic parts of vegetative nervous system. In the course of the baseline study it was found that resting heart rate (HR) in the examined individuals is within normal limits. During the experiment in all subjects there was a trend towards more frequent heartbeat. Each subject at one stage or another stay in a hypoxic oxygen-argon environment heart rate go beyond the group norm, but the extent and duration of these abnormalities were significantly different. Marked increase in middle heart rate during of subjects experiment, fluctuating within a wide range (from 2.3% to 29.1%). Marked increase in middle heart rate during of subjects experiment, fluctuating within a wide range (from 2.3% to 29.1%). This suggests that the ability to adapt to living in the investigated gas environment have marked individual differences. SDNN (mean square deviation of all R-R intervals) is the integral indicator of the total effect of the sinus node to the sympathetic and parasympathetic parts of vegetative nervous system, as well as indicating the higher functional reserves of the cardiovascular systems. Increase in heart rate in the majority of subject was accompanied by an increase in individual SDNN. This suggests that the parasympathetic system is able to balance the increase in activity of the sympathetic system, and functional reserves are

  4. Reference gene alternatives to Gapdh in rodent and human heart failure gene expression studies

    Directory of Open Access Journals (Sweden)

    Levy Finn Olav

    2010-03-01

    Full Text Available Abstract Background Quantitative real-time RT-PCR (RT-qPCR is a highly sensitive method for mRNA quantification, but requires invariant expression of the chosen reference gene(s. In pathological myocardium, there is limited information on suitable reference genes other than the commonly used Gapdh mRNA and 18S ribosomal RNA. Our aim was to evaluate and identify suitable reference genes in human failing myocardium, in rat and mouse post-myocardial infarction (post-MI heart failure and across developmental stages in fetal and neonatal rat myocardium. Results The abundance of Arbp, Rpl32, Rpl4, Tbp, Polr2a, Hprt1, Pgk1, Ppia and Gapdh mRNA and 18S ribosomal RNA in myocardial samples was quantified by RT-qPCR. The expression variability of these transcripts was evaluated by the geNorm and Normfinder algorithms and by a variance component analysis method. Biological variability was a greater contributor to sample variability than either repeated reverse transcription or PCR reactions. Conclusions The most stable reference genes were Rpl32, Gapdh and Polr2a in mouse post-infarction heart failure, Polr2a, Rpl32 and Tbp in rat post-infarction heart failure and Rpl32 and Pgk1 in human heart failure (ischemic disease and cardiomyopathy. The overall most stable reference genes across all three species was Rpl32 and Polr2a. In rat myocardium, all reference genes tested showed substantial variation with developmental stage, with Rpl4 as was most stable among the tested genes.

  5. Heart tissue grown in NASA Bioreactor

    Science.gov (United States)

    2001-01-01

    Lisa Freed and Gordana Vunjak-Novakovic, both of the Massachusetts Institute of Technology (MIT), have taken the first steps toward engineering heart muscle tissue that could one day be used to patch damaged human hearts. Cells isolated from very young animals are attached to a three-dimensional polymer scaffold, then placed in a NASA bioreactor. The cells do not divide, but after about a week start to cornect to form a functional piece of tissue. Functionally connected heart cells that are capable of transmitting electrical signals are the goal for Freed and Vunjak-Novakovic. Electrophysiological recordings of engineered tissue show spontaneous contractions at a rate of 70 beats per minute (a), and paced contractions at rates of 80, 150, and 200 beats per minute respectively (b, c, and d). The NASA Bioreactor provides a low turbulence culture environment which promotes the formation of large, three-dimensional cell clusters. The Bioreactor is rotated to provide gentle mixing of fresh and spent nutrient without inducing shear forces that would damage the cells. Due to their high level of cellular organization and specialization, samples constructed in the bioreactor more closely resemble the original tumor or tissue found in the body. NASA-sponsored bioreactor research has been instrumental in helping scientists to better understand normal and cancerous tissue development. In cooperation with the medical community, the bioreactor design is being used to prepare better models of human colon, prostate, breast and ovarian tumors. Cartilage, bone marrow, heart muscle, skeletal muscle, pancreatic islet cells, liver and kidney are just a few of the normal tissues being cultured in rotating bioreactors by investigators. The work is sponsored by NASA's Office of Biological and Physical Research. The bioreactor is managed by the Biotechnology Cell Science Program at NASA's Johnson Space Center (JSC). Credit: NASA and MIT.

  6. Neural Entrainment to the Beat: The "Missing-Pulse" Phenomenon.

    Science.gov (United States)

    Tal, Idan; Large, Edward W; Rabinovitch, Eshed; Wei, Yi; Schroeder, Charles E; Poeppel, David; Zion Golumbic, Elana

    2017-06-28

    Most humans have a near-automatic inclination to tap, clap, or move to the beat of music. The capacity to extract a periodic beat from a complex musical segment is remarkable, as it requires abstraction from the temporal structure of the stimulus. It has been suggested that nonlinear interactions in neural networks result in cortical oscillations at the beat frequency, and that such entrained oscillations give rise to the percept of a beat or a pulse. Here we tested this neural resonance theory using MEG recordings as female and male individuals listened to 30 s sequences of complex syncopated drumbeats designed so that they contain no net energy at the pulse frequency when measured using linear analysis. We analyzed the spectrum of the neural activity while listening and compared it to the modulation spectrum of the stimuli. We found enhanced neural response in the auditory cortex at the pulse frequency. We also showed phase locking at the times of the missing pulse, even though the pulse was absent from the stimulus itself. Moreover, the strength of this pulse response correlated with individuals' speed in finding the pulse of these stimuli, as tested in a follow-up session. These findings demonstrate that neural activity at the pulse frequency in the auditory cortex is internally generated rather than stimulus-driven. The current results are both consistent with neural resonance theory and with models based on nonlinear response of the brain to rhythmic stimuli. The results thus help narrow the search for valid models of beat perception.SIGNIFICANCE STATEMENT Humans perceive music as having a regular pulse marking equally spaced points in time, within which musical notes are temporally organized. Neural resonance theory (NRT) provides a theoretical model explaining how an internal periodic representation of a pulse may emerge through nonlinear coupling between oscillating neural systems. After testing key falsifiable predictions of NRT using MEG recordings, we

  7. Perceiving temporal regularity in music: the role of auditory event-related potentials (ERPs) in probing beat perception.

    Science.gov (United States)

    Honing, Henkjan; Bouwer, Fleur L; Háden, Gábor P

    2014-01-01

    The aim of this chapter is to give an overview of how the perception of a regular beat in music can be studied in humans adults, human newborns, and nonhuman primates using event-related brain potentials (ERPs). Next to a review of the recent literature on the perception of temporal regularity in music, we will discuss in how far ERPs, and especially the component called mismatch negativity (MMN), can be instrumental in probing beat perception. We conclude with a discussion on the pitfalls and prospects of using ERPs to probe the perception of a regular beat, in which we present possible constraints on stimulus design and discuss future perspectives.

  8. Detrended Fluctuation Analysis on Cardiac Pulses in Both, Animal Models and Humans: A Computation for an Early Prognosis of Cardiovascular Disease

    Directory of Open Access Journals (Sweden)

    Toru Yazawa

    2008-04-01

    Full Text Available We analyzed the heartbeat interval by the detrended fluctuation analysis (DFA in models and humans. In models, the myocardium of the healthy heart contracted regularly. The deteriorated heart model, however, showed alternating beats so-called "alternans." The DFA revealed that if the heart is having "alternans" exhibited there is a declined scaling exponent (~0.5. In humans, the heart that had "alternans" also showed a low scaling exponent (~0.6. We consider that the coexistence of "alternans" and a low scaling exponent can be a risk marker in predictive and preventative diagnosis, supporting the idea that "alternans" can be a harbinger of sudden death.

  9. 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...

  10. Neural responses to sounds presented on and off the beat of ecologically valid music

    Directory of Open Access Journals (Sweden)

    Adam eTierney

    2013-05-01

    Full Text Available The tracking of rhythmic structure is a vital component of speech and music perception. It is known that sequences of identical sounds can give rise to the percept of alternating strong and weak sounds, and that this percept is linked to enhanced cortical and oscillatory responses. The neural correlates of the perception of rhythm elicited by ecologically valid, complex stimuli, however, remain unexplored. Here we report the effects of a stimulus’ alignment with the beat on the brain’s processing of sound. Human subjects listened to short popular music pieces while simultaneously hearing a target sound. Cortical and brainstem electrophysiological onset responses to the sound were enhanced when it was presented on the beat of the music, as opposed to shifted away from it. Moreover, the size of the effect of alignment with the beat on the cortical response correlated strongly with the ability to tap to a beat, suggesting that the ability to synchronize to the beat of simple isochronous stimuli and the ability to track the beat of complex, ecologically valid stimuli may rely on overlapping neural resources. These results suggest that the perception of musical rhythm may have robust effects on processing throughout the auditory system.

  11. Intermode beat stabilized laser with frequency pulling.

    Science.gov (United States)

    Yokoyama, S; Araki, T; Suzuki, N

    1994-01-20

    A frequency-stabilized two-mode He-Ne laser has been developed. The intermode beat frequency of the experimental laser was approximately 600 MHz for a 25-cm cavity. The laser frequency in which the mode stands is pulled to the center of the gain curve (frequency pulling). The degree of pulling depends on where the longitudinal modes stand in the broadened gain curve. Beat frequency is thereby changed periodically of the order of hundreds of kilohertz with respect to cavity expansion. The frequency pulling was effectively used for frequency stabilization of the laser. The standing position of the longitudinal mode lights was locked in the gain curve by controlling the change of intermode beat frequency. A microwave mixer was applied to extract the frequency change of the intermode beat. Excellent frequency stability (10(10) for the laser oscillation and 10(6) for the beat frequency) was attained. The polarization orthogonality of the proposed laser was superior to that of Zeeman lasers.

  12. 3D engineered cardiac tissue models of human heart disease: learning more from our mice.

    Science.gov (United States)

    Ralphe, J Carter; de Lange, Willem J

    2013-02-01

    Mouse engineered cardiac tissue constructs (mECTs) are a new tool available to study human forms of genetic heart disease within the laboratory. The cultured strips of cardiac cells generate physiologic calcium transients and twitch force, and respond to electrical pacing and adrenergic stimulation. The mECT can be made using cells from existing mouse models of cardiac disease, providing a robust readout of contractile performance and allowing a rapid assessment of genotype-phenotype correlations and responses to therapies. mECT represents an efficient and economical extension to the existing tools for studying cardiac physiology. Human ECTs generated from iPSCMs represent the next logical step for this technology and offer significant promise of an integrated, fully human, cardiac tissue model.

  13. Climate Wrongs and Human Rights. Putting people at the heart of climate-change policy

    Energy Technology Data Exchange (ETDEWEB)

    Raworth, K. (ed.) (and others)

    2008-09-15

    In failing to tackle climate change with urgency, rich countries are effectively violating the human rights of millions of the world's poorest people. Continued excessive greenhouse-gas emissions primarily from industrialised nations are - with scientific certainty - creating floods, droughts, hurricanes, sea-level rise, and seasonal unpredictability. The result is failed harvests, disappearing islands, destroyed homes, water scarcity, and deepening health crises, which are undermining millions of peoples' rights to life, security, food, water, health, shelter, and culture. Such rights violations could never truly be remedied in courts of law. Human-rights principles must be put at the heart of international climate-change policy making now, in order to stop this irreversible damage to humanity's future.

  14. 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 the space missions. The wearable physiological monitor...

  15. 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 ...

  16. FDA-Approved Devices That Keep the Heart Beating

    Science.gov (United States)

    ... Emiten Radiación Fraude en la Salud Medicamentos Nutrición Productos Veterinarios Productos de Tabaco Salud Infantil Salud de la Mujer Suplementos Dietéticos Vacunas, Sangre y Productos Biológicos Page Last Updated: 02/16/2017 Note: ...

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

    Science.gov (United States)

    Potts, Michael

    2007-08-24

    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.

  18. Exercise Beats Weight Loss At Helping Seniors' Hearts

    Science.gov (United States)

    ... in older adults than losing weight does. "Any physical activity is positive for cardiovascular health, and in elderly people of all weights, walking, ... physical activity plays a crucial role in the health of middle age to elderly ... disease." Expert guidelines currently recommend 150 minutes a ...

  19. 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.

  20. The new heart of the PS is beating strongly

    CERN Multimedia

    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...

  1. Gender differences in electrophysiological gene expression in failing and non-failing human hearts.

    Directory of Open Access Journals (Sweden)

    Christina M Ambrosi

    Full Text Available The increasing availability of human cardiac tissues for study are critically important in increasing our understanding of the impact of gender, age, and other parameters, such as medications and cardiac disease, on arrhythmia susceptibility. In this study, we aimed to compare the mRNA expression of 89 ion channel subunits, calcium handling proteins, and transcription factors important in cardiac conduction and arrhythmogenesis in the left atria (LA and ventricles (LV of failing and nonfailing human hearts of both genders. Total RNA samples, prepared from failing male (n = 9 and female (n = 7, and from nonfailing male (n = 9 and female (n = 9 hearts, were probed using custom-designed Taqman gene arrays. Analyses were performed to explore the relationships between gender, failure state, and chamber expression. Hierarchical cluster analysis revealed chamber specific expression patterns, but failed to identify disease- or gender-dependent clustering. Gender-specific analysis showed lower expression levels in transcripts encoding for K(v4.3, KChIP2, K(v1.5, and K(ir3.1 in the failing female as compared with the male LA. Analysis of LV transcripts, however, did not reveal significant differences based on gender. Overall, our data highlight the differential expression and transcriptional remodeling of ion channel subunits in the human heart as a function of gender and cardiac disease. Furthermore, the availability of such data sets will allow for the development of disease-, gender-, and, most importantly, patient-specific cardiac models, with the ability to utilize such information as mRNA expression to predict cardiac phenotype.

  2. Hyperpolarized 13C Metabolic MRI of the Human Heart: Initial Experience.

    Science.gov (United States)

    Cunningham, Charles H; Lau, Justin Y C; Chen, Albert P; Geraghty, Benjamin J; Perks, William J; Roifman, Idan; Wright, Graham A; Connelly, Kim A

    2016-11-11

    Altered cardiac energetics is known to play an important role in the progression toward heart failure. A noninvasive method for imaging metabolic markers that could be used in longitudinal studies would be useful for understanding therapeutic approaches that target metabolism. To demonstrate the first hyperpolarized (13)C metabolic magnetic resonance imaging of the human heart. Four healthy subjects underwent conventional proton cardiac magnetic resonance imaging followed by (13)C imaging and spectroscopic acquisition immediately after intravenous administration of a 0.1 mmol/kg dose of hyperpolarized [1-(13)C]pyruvate. All subjects tolerated the procedure well with no adverse effects reported ≤1 month post procedure. The [1-(13)C]pyruvate signal appeared within the chambers but not within the muscle. Imaging of the downstream metabolites showed (13)C-bicarbonate signal mainly confined to the left ventricular myocardium, whereas the [1-(13)C]lactate signal appeared both within the chambers and in the myocardium. The mean (13)C image signal:noise ratio was 115 for [1-(13)C]pyruvate, 56 for (13)C-bicarbonate, and 53 for [1-(13)C]lactate. These results represent the first (13)C images of the human heart. The appearance of (13)C-bicarbonate signal after administration of hyperpolarized [1-(13)C]pyruvate was readily detected in this healthy cohort (n=4). This shows that assessment of pyruvate metabolism in vivo in humans is feasible using current technology. URL: https://www.clinicaltrials.gov. Unique identifier: NCT02648009. © 2016 The Authors.

  3. Redox proteomics identification of oxidatively modified myocardial proteins in human heart failure: implications for protein function.

    Directory of Open Access Journals (Sweden)

    Maura Brioschi

    Full Text Available Increased oxidative stress in a failing heart may contribute to the pathogenesis of heart failure (HF. The aim of this study was to identify the oxidised proteins in the myocardium of HF patients and analyse the consequences of oxidation on protein function. The carbonylated proteins in left ventricular tissue from failing (n = 14 and non-failing human hearts (n = 13 were measured by immunoassay and identified by proteomics. HL-1 cardiomyocytes were incubated in the presence of stimuli relevant for HF in order to assess the generation of reactive oxygen species (ROS, the induction of protein carbonylation, and its consequences on protein function. The levels of carbonylated proteins were significantly higher in the HF patients than in the controls (p<0.01. We identified two proteins that mainly underwent carbonylation: M-type creatine kinase (M-CK, whose activity is impaired, and, to a lesser extent, α-cardiac actin. Exposure of cardiomyocytes to angiotensin II and norepinephrine led to ROS generation and M-CK carbonylation with loss of its enzymatic activity. Our findings indicate that protein carbonylation is increased in the myocardium during HF and that these oxidative changes may help to explain the decreased CK activity and consequent defects in energy metabolism observed in HF.

  4. Redox proteomics identification of oxidatively modified myocardial proteins in human heart failure: implications for protein function.

    Science.gov (United States)

    Brioschi, Maura; Polvani, Gianluca; Fratto, Pasquale; Parolari, Alessandro; Agostoni, Piergiuseppe; Tremoli, Elena; Banfi, Cristina

    2012-01-01

    Increased oxidative stress in a failing heart may contribute to the pathogenesis of heart failure (HF). The aim of this study was to identify the oxidised proteins in the myocardium of HF patients and analyse the consequences of oxidation on protein function. The carbonylated proteins in left ventricular tissue from failing (n = 14) and non-failing human hearts (n = 13) were measured by immunoassay and identified by proteomics. HL-1 cardiomyocytes were incubated in the presence of stimuli relevant for HF in order to assess the generation of reactive oxygen species (ROS), the induction of protein carbonylation, and its consequences on protein function. The levels of carbonylated proteins were significantly higher in the HF patients than in the controls (p<0.01). We identified two proteins that mainly underwent carbonylation: M-type creatine kinase (M-CK), whose activity is impaired, and, to a lesser extent, α-cardiac actin. Exposure of cardiomyocytes to angiotensin II and norepinephrine led to ROS generation and M-CK carbonylation with loss of its enzymatic activity. Our findings indicate that protein carbonylation is increased in the myocardium during HF and that these oxidative changes may help to explain the decreased CK activity and consequent defects in energy metabolism observed in HF.

  5. Sex differences in healthy human heart rate variability: A meta-analysis.

    Science.gov (United States)

    Koenig, Julian; Thayer, Julian F

    2016-05-01

    The present meta-analysis aimed to quantify current evidence on sex differences in the autonomic control of the heart, indexed by measures of heart rate variability (HRV) in healthy human subjects. An extensive search of the literature yielded 2020 titles and abstracts, of which 172 provided sufficient reporting of sex difference in HRV. Data from 63,612 participants (31,970 females) were available for analysis. Meta-analysis yielded a total of 1154 effect size estimates (k) across 50 different measures of HRV in a cumulated total of 296,247 participants. Females showed a significantly lower mean RR interval and standard deviation of RR intervals (SDNN). The power spectral density of HRV in females is characterized by significantly less total power that contains significantly greater high- (HF) and less low-frequency (LF) power. This is further reflected by a lower LF/HF ratio. Meta-regression revealed significant effects of age, respiration control and the length of recording available for analysis. Although women showed greater mean heart rate, they showed greater vagal activity indexed by HF power of HRV. Underlying mechanisms of these findings are discussed.

  6. Enhanced engraftment, proliferation, and therapeutic potential in heart using optimized human iPSC-derived cardiomyocytes

    Science.gov (United States)

    Funakoshi, Shunsuke; Miki, Kenji; Takaki, Tadashi; Okubo, Chikako; Hatani, Takeshi; Chonabayashi, Kazuhisa; Nishikawa, Misato; Takei, Ikue; Oishi, Akiko; Narita, Megumi; Hoshijima, Masahiko; Kimura, Takeshi; Yamanaka, Shinya; Yoshida, Yoshinori

    2016-01-01

    Human pluripotent stem cell-derived cardiomyocytes (CMs) are a promising tool for cardiac cell therapy. Although transplantation of induced pluripotent stem cell (iPSC)-derived CMs have been reported in several animal models, the treatment effect was limited, probably due to poor optimization of the injected cells. To optimize graft cells for cardiac reconstruction, we compared the engraftment efficiency of intramyocardially-injected undifferentiated-iPSCs, day4 mesodermal cells, and day8, day20, and day30 purified iPSC-CMs after initial differentiation by tracing the engraftment ratio (ER) using in vivo bioluminescence imaging. This analysis revealed the ER of day20 CMs was significantly higher compared to other cells. Transplantation of day20 CMs into the infarcted hearts of immunodeficient mice showed good engraftment, and echocardiography showed significant functional improvement by cell therapy. Moreover, the imaging signal and ratio of Ki67-positive CMs at 3 months post injection indicated engrafted CMs proliferated in the host heart. Although this graft growth reached a plateau at 3 months, histological analysis confirmed progressive maturation from 3 to 6 months. These results suggested that day20 CMs had very high engraftment, proliferation, and therapeutic potential in host mouse hearts. They also demonstrate this model can be used to track the fate of transplanted cells over a long time. PMID:26743035

  7. Viscoelastic behaviour of human blood and polyacrylamide model fluids for heart valve testing

    Science.gov (United States)

    Lerche, Dietmar; Vlastos, Georgios; Koch, Brigitte; Pohl, Manfred; Affeld, Klaus

    1993-06-01

    New heart valves and other cardiovascular assist systems have to be tested for hydrodynamic performance. In place of human blood simple model fluids like glycerol solutions are employed often due to ethical and practical reasons. But blood exhibits complex non-Newtonian and viscoelastic behaviour. Rheological blood properties are reviewed based on literature and own experimental results. Furthermore we studied polymer solutions with respect to blood-like flow behaviour. Rheology was assessed by means of the low shear rotational viscometer (LS 40, Mettler-Toledo, Switzerland) under stationary and dynamic shear conditions (variation of frequency and angular displacement).

  8. In vitro culture of embryonic hearts from guppy fish (Poecilia reticulata )

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Forty embryonic hearts were taken out byanatomical needle from denuded embryos of the ovovivipar ity guppy fish that were dechorioned by mechanic method or by trypsin digestion, and were in vitro cultured. In the cul tured hearts, 80% have maintained beating in vitro for 4weeks, and the longest record for beating was 142 d. Owing to fish embryo transparency, beating frequency and blood color changes are easily viewed from the embryonic hearts under a dissecting microscope. The current study established the in vitro culture method of embryonic hearts in guppy fish,which can be used as a model for the study of heart and car diovascular system in vertebrates.

  9. Nonlinear and stochastic dynamics in the heart

    Energy Technology Data Exchange (ETDEWEB)

    Qu, Zhilin, E-mail: zqu@mednet.ucla.edu [Department of Medicine (Cardiology), David Geffen School of Medicine, University of California, Los Angeles, CA 90095 (United States); Hu, Gang [Department of Physics, Beijing Normal University, Beijing 100875 (China); Garfinkel, Alan [Department of Medicine (Cardiology), David Geffen School of Medicine, University of California, Los Angeles, CA 90095 (United States); Department of Integrative Biology and Physiology, University of California, Los Angeles, CA 90095 (United States); Weiss, James N. [Department of Medicine (Cardiology), David Geffen School of Medicine, University of California, Los Angeles, CA 90095 (United States); Department of Physiology, David Geffen School of Medicine, University of California, Los Angeles, CA 90095 (United States)

    2014-10-10

    In a normal human life span, the heart beats about 2–3 billion times. Under diseased conditions, a heart may lose its normal rhythm and degenerate suddenly into much faster and irregular rhythms, called arrhythmias, which may lead to sudden death. The transition from a normal rhythm to an arrhythmia is a transition from regular electrical wave conduction to irregular or turbulent wave conduction in the heart, and thus this medical problem is also a problem of physics and mathematics. In the last century, clinical, experimental, and theoretical studies have shown that dynamical theories play fundamental roles in understanding the mechanisms of the genesis of the normal heart rhythm as well as lethal arrhythmias. In this article, we summarize in detail the nonlinear and stochastic dynamics occurring in the heart and their links to normal cardiac functions and arrhythmias, providing a holistic view through integrating dynamics from the molecular (microscopic) scale, to the organelle (mesoscopic) scale, to the cellular, tissue, and organ (macroscopic) scales. We discuss what existing problems and challenges are waiting to be solved and how multi-scale mathematical modeling and nonlinear dynamics may be helpful for solving these problems.

  10. Transcriptional regulation of the sodium channel gene (SCN5A) by GATA4 in human heart.

    Science.gov (United States)

    Tarradas, Anna; Pinsach-Abuin, Mel Lina; Mackintosh, Carlos; Llorà-Batlle, Oriol; Pérez-Serra, Alexandra; Batlle, Montserrat; Pérez-Villa, Félix; Zimmer, Thomas; Garcia-Bassets, Ivan; Brugada, Ramon; Beltran-Alvarez, Pedro; Pagans, Sara

    2017-01-01

    Aberrant expression of the sodium channel gene (SCN5A) has been proposed to disrupt cardiac action potential and cause human cardiac arrhythmias, but the mechanisms of SCN5A gene regulation and dysregulation still remain largely unexplored. To gain insight into the transcriptional regulatory networks of SCN5A, we surveyed the promoter and first intronic regions of the SCN5A gene, predicting the presence of several binding sites for GATA transcription factors (TFs). Consistent with this prediction, chromatin immunoprecipitation (ChIP) and sequential ChIP (Re-ChIP) assays show co-occupancy of cardiac GATA TFs GATA4 and GATA5 on promoter and intron 1 SCN5A regions in fresh-frozen human left ventricle samples. Gene reporter experiments show GATA4 and GATA5 synergism in the activation of the SCN5A promoter, and its dependence on predicted GATA binding sites. GATA4 and GATA6 mRNAs are robustly expressed in fresh-frozen human left ventricle samples as measured by highly sensitive droplet digital PCR (ddPCR). GATA5 mRNA is marginally but still clearly detected in the same samples. Importantly, GATA4 mRNA levels are strongly and positively correlated with SCN5A transcript levels in the human heart. Together, our findings uncover a novel mechanism of GATA TFs in the regulation of the SCN5A gene in human heart tissue. Our studies suggest that GATA5 but especially GATA4 are main contributors to SCN5A gene expression, thus providing a new paradigm of SCN5A expression regulation that may shed new light into the understanding of cardiac disease. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

  11. Load Response of the Flagellar Beat

    Science.gov (United States)

    Klindt, Gary S.; Ruloff, Christian; Wagner, Christian; Friedrich, Benjamin M.

    2016-12-01

    Cilia and flagella exhibit regular bending waves that perform mechanical work on the surrounding fluid, to propel cellular swimmers and pump fluids inside organisms. Here, we quantify a force-velocity relationship of the beating flagellum, by exposing flagellated Chlamydomonas cells to controlled microfluidic flows. A simple theory of flagellar limit-cycle oscillations, calibrated by measurements in the absence of flow, reproduces this relationship quantitatively. We derive a link between the energy efficiency of the flagellar beat and its ability to synchronize to oscillatory flows.

  12. Electrical admittance for filling of the heart during lower body negative pressure in humans

    DEFF Research Database (Denmark)

    Cai, Yan; Holm, Søren; Jenstrup, Morten;

    2000-01-01

    cardiac output, electrical impedance, heart rate, positron emission tomography, technetium-labeled erythrocytes......cardiac output, electrical impedance, heart rate, positron emission tomography, technetium-labeled erythrocytes...

  13. Evidence for Intramyocardial Disruption of Lipid Metabolism and Increased Myocardial Ketone Utilization in Advanced Human Heart Failure.

    Science.gov (United States)

    Bedi, Kenneth C; Snyder, Nathaniel W; Brandimarto, Jeffrey; Aziz, Moez; Mesaros, Clementina; Worth, Andrew J; Wang, Linda L; Javaheri, Ali; Blair, Ian A; Margulies, Kenneth B; Rame, J Eduardo

    2016-02-23

    The failing human heart is characterized by metabolic abnormalities, but these defects remains incompletely understood. In animal models of heart failure there is a switch from a predominance of fatty acid utilization to the more oxygen-sparing carbohydrate metabolism. Recent studies have reported decreases in myocardial lipid content, but the inclusion of diabetic and nondiabetic patients obscures the distinction of adaptations to metabolic derangements from adaptations to heart failure per se. We performed both unbiased and targeted myocardial lipid surveys using liquid chromatography-mass spectroscopy in nondiabetic, lean, predominantly nonischemic, advanced heart failure patients at the time of heart transplantation or left ventricular assist device implantation. We identified significantly decreased concentrations of the majority of myocardial lipid intermediates, including long-chain acylcarnitines, the primary subset of energetic lipid substrate for mitochondrial fatty acid oxidation. We report for the first time significantly reduced levels of intermediate and anaplerotic acyl-coenzyme A (CoA) species incorporated into the Krebs cycle, whereas the myocardial concentration of acetyl-CoA was significantly increased in end-stage heart failure. In contrast, we observed an increased abundance of ketogenic β-hydroxybutyryl-CoA, in association with increased myocardial utilization of β-hydroxybutyrate. We observed a significant increase in the expression of the gene encoding succinyl-CoA:3-oxoacid-CoA transferase, the rate-limiting enzyme for myocardial oxidation of β-hydroxybutyrate and acetoacetate. These findings indicate increased ketone utilization in the severely failing human heart independent of diabetes mellitus, and they support the role of ketone bodies as an alternative fuel and myocardial ketone oxidation as a key metabolic adaptation in the failing human heart. © 2016 American Heart Association, Inc.

  14. Beat that Word: How Listeners Integrate Beat Gesture and Focus in Multimodal Speech Discourse.

    Science.gov (United States)

    Dimitrova, Diana; Chu, Mingyuan; Wang, Lin; Özyürek, Asli; Hagoort, Peter

    2016-09-01

    Communication is facilitated when listeners allocate their attention to important information (focus) in the message, a process called "information structure." Linguistic cues like the preceding context and pitch accent help listeners to identify focused information. In multimodal communication, relevant information can be emphasized by nonverbal cues like beat gestures, which represent rhythmic nonmeaningful hand movements. Recent studies have found that linguistic and nonverbal attention cues are integrated independently in single sentences. However, it is possible that these two cues interact when information is embedded in context, because context allows listeners to predict what information is important. In an ERP study, we tested this hypothesis and asked listeners to view videos capturing a dialogue. In the critical sentence, focused and nonfocused words were accompanied by beat gestures, grooming hand movements, or no gestures. ERP results showed that focused words are processed more attentively than nonfocused words as reflected in an N1 and P300 component. Hand movements also captured attention and elicited a P300 component. Importantly, beat gesture and focus interacted in a late time window of 600-900 msec relative to target word onset, giving rise to a late positivity when nonfocused words were accompanied by beat gestures. Our results show that listeners integrate beat gesture with the focus of the message and that integration costs arise when beat gesture falls on nonfocused information. This suggests that beat gestures fulfill a unique focusing function in multimodal discourse processing and that they have to be integrated with the information structure of the message.

  15. 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.

  16. Developing a novel comprehensive framework for the investigation of cellular and whole heart electrophysiology in the in situ human heart: historical perspectives, current progress and future prospects.

    Science.gov (United States)

    Taggart, Peter; Orini, Michele; Hanson, Ben; Hayward, Martin; Clayton, Richard; Dobrzynski, Halina; Yanni, Joseph; Boyett, Mark; Lambiase, Pier D

    2014-08-01

    Understanding the mechanisms of fatal ventricular arrhythmias is of great importance. In view of the many electrophysiological differences that exist between animal species and humans, the acquisition of basic electrophysiological data in the intact human heart is essential to drive and complement experimental work in animal and in-silico models. Over the years techniques have been developed to obtain basic electrophysiological signals directly from the patients by incorporating these measurements into routine clinical procedures which access the heart such as cardiac catheterisation and cardiac surgery. Early recordings with monophasic action potentials provided valuable information including normal values for the in vivo human heart, cycle length dependent properties, the effect of ischaemia, autonomic nervous system activity, and mechano-electric interaction. Transmural recordings addressed the controversial issue of the mid myocardial "M" cell. More recently, the technique of multielectrode mapping (256 electrodes) developed in animal models has been extended to humans, enabling mapping of activation and repolarisation on the entire left and right ventricular epicardium in patients during cardiac surgery. Studies have examined the issue of whether ventricular fibrillation was driven by a "mother" rotor with inhomogeneous and fragmented conduction as in some animal models, or by multiple wavelets as in other animal studies; results showed that both mechanisms are operative in humans. The simpler spatial organisation of human VF has important implications for treatment and prevention. To link in-vivo human electrophysiological mapping with cellular biophysics, multielectrode mapping is now being combined with myocardial biopsies. This technique enables region-specific electrophysiology changes to be related to underlying cellular biology, for example: APD alternans, which is a precursor of VF and sudden death. The mechanism is incompletely understood but related

  17. Metabolic Characteristics of Human Hearts Preserved for 12 Hours by Static Storage, Antegrade Perfusion or Retrograde Coronary Sinus Perfusion

    Science.gov (United States)

    Cobert, Michael L.; Merritt, Matthew E.; West, LaShondra M.; Ayers, Colby; Jessen, Michael E.; Peltz, Matthias

    2014-01-01

    Objective(s) Machine perfusion of donor hearts is a promising strategy to increase the donor pool. Antegrade perfusion is effective but can lead to aortic valve incompetence and non-nutrient flow. Experience with retrograde coronary sinus perfusion of donor hearts has been limited. We tested the hypothesis that retrograde perfusion could support myocardial metabolism over an extended donor ischemic interval. Methods Human hearts from donors rejected or not offered for transplantation were preserved for 12 hours in University of Wisconsin Machine Perfusion Solution by: 1. Static hypothermic storage 2. Hypothermic antegrade machine perfusion or 3. Hypothermic retrograde machine perfusion. Myocardial oxygen consumption (MVO2), and lactate accumulation were measured. Ventricular tissue was collected for proton (1H) and phosphorus-31 (31P) magnetic resonance spectroscopy (MRS) to evaluate the metabolic state of the myocardium. Myocardial water content was determined at end-experiment. Results Stable perfusion parameters were maintained throughout the perfusion period with both perfusion techniques. Lactate/alanine ratios were lower in perfused hearts compared to static hearts (pperfused groups. High energy phosphates were better preserved in both perfused groups (pperfused (80.2±.8%) compared to both antegrade perfused (76.6±.8%, p=.02) and static storage hearts (76.7±1%, p=.02). Conclusions In conclusion, machine perfusion by either the antegrade or the retrograde technique can support myocardial metabolism over long intervals. Machine perfusion appears promising for long term preservation of human donor hearts. PMID:24642559

  18. 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.

  19. Assembly of the cardiac intercalated disk during pre- and postnatal development of the human heart.

    Directory of Open Access Journals (Sweden)

    Arnold Vreeker

    Full Text Available BACKGROUND: In cardiac muscle, the intercalated disk (ID at the longitudinal cell-edges of cardiomyocytes provides as a macromolecular infrastructure that integrates mechanical and electrical coupling within the heart. Pathophysiological disturbance in composition of this complex is well known to trigger cardiac arrhythmias and pump failure. The mechanisms underlying assembly of this important cellular domain in human heart is currently unknown. METHODS: We collected 18 specimens from individuals that died from non-cardiovascular causes. Age of the specimens ranged from a gestational age of 15 weeks through 11 years postnatal. Immunohistochemical labeling was performed against proteins comprising desmosomes, adherens junctions, the cardiac sodium channel and gap junctions to visualize spatiotemporal alterations in subcellular location of the proteins. RESULTS: Changes in spatiotemporal localization of the adherens junction proteins (N-cadherin and ZO-1 and desmosomal proteins (plakoglobin, desmoplakin and plakophilin-2 were identical in all subsequent ages studied. After an initial period of diffuse and lateral labelling, all proteins were fully localized in the ID at approximately 1 year after birth. Nav1.5 that composes the cardiac sodium channel and the gap junction protein Cx43 follow a similar pattern but their arrival in the ID is detected at (much later stages (two years for Nav1.5 and seven years for Cx43, respectively. CONCLUSION: Our data on developmental maturation of the ID in human heart indicate that generation of the mechanical junctions at the ID precedes that of the electrical junctions with a significant difference in time. In addition arrival of the electrical junctions (Nav1.5 and Cx43 is not uniform since sodium channels localize much earlier than gap junction channels.

  20. 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).

  1. Maximal heart rate does not limit cardiovascular capacity in healthy humans

    DEFF Research Database (Denmark)

    Munch, G D W; Svendsen, J H; Damsgaard, R

    2014-01-01

    In humans, maximal aerobic power (VO2 max ) is associated with a plateau in cardiac output (Q), but the mechanisms regulating the interplay between maximal heart rate (HRmax) and stroke volume (SV) are unclear. To evaluate the effect of tachycardia and elevations in HRmax on cardiovascular function...... and capacity during maximal exercise in healthy humans, 12 young male cyclists performed incremental cycling and one-legged knee-extensor exercise (KEE) to exhaustion with and without right atrial pacing to increase HR. During control cycling, Q and leg blood flow increased up to 85% of maximal workload (WLmax...... and RAP (P exercise, suggesting that HRmax and myocardial work capacity do not limit VO2 max in healthy...

  2. In vitro cultured progenitors and precursors of cardiac cell lineages from human normal and post-ischemic hearts

    Directory of Open Access Journals (Sweden)

    F Di Meglio

    2009-08-01

    Full Text Available The demonstration of the presence of dividing primitive cells in damaged hearts has sparked increased interest about myocardium regenerative processes. We examined the rate and the differentiation of in vitro cultured resident cardiac primitive cells obtained from pathological and normal human hearts in order to evaluate the activation of progenitors and precursors of cardiac cell lineages in post-ischemic human hearts. The precursors and progenitors of cardiomyocyte, smooth muscle and endothelial lineage were identified by immunocytochemistry and the expression of characteristic markers was studied by western blot and RT-PCR. The amount of proteins characteristic for cardiac cells (a-SA and MHC, VEGFR-2 and FVIII, SMA for the precursors of cardiomyocytes, endothelial and smooth muscle cells, respectively inclines toward an increase in both a-SA and MHC. The increased levels of FVIII and VEGFR2 are statistically significant, suggesting an important re-activation of neoangiogenesis. At the same time, the augmented expression of mRNA for Nkx 2.5, the trascriptional factor for cardiomyocyte differentiation, confirms the persistence of differentiative processes in terminally injured hearts. Our study would appear to confirm the activation of human heart regeneration potential in pathological conditions and the ability of its primitive cells to maintain their proliferative capability in vitro. The cardiac cell isolation method we used could be useful in the future for studying modifications to the microenvironment that positively influence cardiac primitive cell differentiation or inhibit, or retard, the pathological remodeling and functional degradation of the heart.

  3. Anatomic Localization and Autonomic Modulation of AV Junctional Rhythm in Failing Human Hearts

    Science.gov (United States)

    Fedorov, Vadim V.; Ambrosi, Christina M.; Kostecki, Geran; Hucker, William J.; Glukhov, Alexey V.; Wuskell, Joseph P.; Loew, Leslie M.; Moazami, Nader; Efimov, Igor R.

    2011-01-01

    Background The structure-function relationship in the atrioventricular junction (AVJ) of various animal species has been investigated in detail, however less is known about the human AVJ. In this study, we performed high-resolution optical mapping of the human AVJ (n=6) to define its pacemaker properties and response to autonomic stimulation. Methods and Results Isolated, coronary-perfused AVJ preparations from failing human hearts (n=6, 53±6 years) were optically mapped using the near-infrared, voltage-sensitive dye, di-4-ANBDQBS, with isoproterenol (Iso, 1 μM) and acetylcholine (ACh, 1μM). An algorithm detecting multiple components of optical action potentials was used to reconstruct multi-layered intramural AVJ activation and to identify specialized slow and fast conduction pathways (SP and FP). The anatomical origin and propagation of pacemaker activity was verified via histology. Spontaneous AVJ rhythms of 29±11 bpm (n=6) originated in the nodal-His region (NH, n=3) and/or the proximal His bundle (H, n=4). Iso accelerated the AVJ rhythm to 69±12 bpm (n=5); shifted the leading pacemaker to the transitional cell (TC) regions near the FP and SP (n=4) and/or coronary sinus (n=2); and triggered reentrant arrhythmias (n=2). ACh (n=4) decreased the AVJ rhythm to 18±4 bpm; slowed FP/SP conduction leading to block between the AVJ and atrium; and shifted the pacemaker to either the TC or TC/NH (bifocal activation). Conclusions We have demonstrated that the AVJ pacemaker in failing human hearts is located in the NH or H-regions and can be modified with autonomic stimulation. Moreover, we found that both the FP and SP are involved in anterograde and retrograde conduction. PMID:21646375

  4. Human care system for heart-rate and human-movement trajectory in home and its application to detect mental disease

    Science.gov (United States)

    Hata, Yutaka; Kanazawa, Seigo; Endo, Maki; Tsuchiya, Naoki; Nakajima, Hiroshi

    2012-06-01

    This paper proposes a heart rate monitoring system for detecting autonomic nervous system by the heart rate variability using an air pressure sensor to diagnose mental disease. Moreover, we propose a human behavior monitoring system for detecting the human trajectory in home by an infrared camera. In day and night times, the human behavior monitoring system detects the human movement in home. The heart rate monitoring system detects the heart rate in bed in night time. The air pressure sensor consists of a rubber tube, cushion cover and pressure sensor, and it detects the heart rate by setting it to bed. It unconstraintly detects the RR-intervals; thereby the autonomic nervous system can be assessed. The autonomic nervous system analysis can examine the mental disease. While, the human behavior monitoring system obtains distance distribution image by an infrared camera. It classifies adult, child and the other object from distance distribution obtained by the camera, and records their trajectories. This behavior, i.e., trajectory in home, strongly corresponds to cognitive disorders. Thus, the total system can detect mental disease and cognitive disorders by uncontacted sensors to human body.

  5. Correlation between endogenous polyamines in human cardiac tissues and clinical parameters in patients with heart failure.

    Science.gov (United States)

    Meana, Clara; Rubín, José Manuel; Bordallo, Carmen; Suárez, Lorena; Bordallo, Javier; Sánchez, Manuel

    2016-02-01

    Polyamines contribute to several physiological and pathological processes, including cardiac hypertrophy in experimental animals. This involves an increase in ornithine decarboxylase (ODC) activity and intracellular polyamines associated with cyclic adenosine monophosphate (cAMP) increases. The aim of the study was to establish the role of these in the human heart in living patients. For this, polyamines (by high performance liquid chromatography) and the activity of ODC and N(1)-acetylpolyamine oxidases (APAO) were determined in the right atrial appendage of 17 patients undergoing extracorporeal circulation to correlate with clinical parameters. There existed enzymatic activity associated with the homeostasis of polyamines. Left atria size was positively associated with ODC (r = 0.661, P = 0.027) and negatively with APAO-N(1) -acetylspermine (r = -0.769, P = 0.026), suggesting that increased levels of polyamines are associated with left atrial hemodynamic overload. Left ventricular ejection fraction (LVEF) and heart rate were positively associated with spermidine (r = 0.690, P = 0.003; r = 0.590, P = 0.021) and negatively with N(1)-acetylspermidine (r = -0.554, P = 0.032; r = -0.644, P = 0.018). LVEF was negatively correlated with cAMP levels (r = -0.835, P = 0.001) and with cAMP/ODC (r = -0.794, P = 0.011), cAMP/spermidine (r = -0.813, P = 0.001) and cAMP/spermine (r = -0.747, P = 0.003) ratios. Abnormal LVEF patients showed decreased ODC activity and spermidine, and increased N(1) -acetylspermidine, and cAMP. Spermine decreased in congestive heart failure patients. The trace amine isoamylamine negatively correlated with septal wall thickness (r = -0.634, P = 0.008) and was increased in cardiac heart failure. The results indicated that modifications in polyamine homeostasis might be associated with cardiac function and remodelling. Increased cAMP might have a deleterious effect on function. Further studies should confirm these findings and the involvement of

  6. Using intramyocardial electrograms combined with other noninvasive methods for monitoring acute rejection following human heart transplantation

    Institute of Scientific and Technical Information of China (English)

    JIA Yi-xin; MENG Xu; SUN Ling-bo; HAN Jie; CHEN Yang-tian

    2009-01-01

    Background Acute allograft rejection in heart transplantation remains as one of the major complications. Obligatory graft surveillance is still achieved with the invasive and expensive endomyocardial biopsy (EMB). Our study aimed to study the use of intramyocardial electrograms combined with other noninvasive methods for the monitoring of acute rejection after human heart transplantation. Methods Permanent pacemakers were implanted in 58 patients undergoing heart transplantations. Intramyocardial electrograms (IMEG) were recorded periodically and the results were compared with those from EMBs. The R wave amplitude of the IMEG was used as the index value, the average R wave amplitude at the third week following transplantation was considered as the baseline, and a reduction of >20% compared with the baseline was regarded as a positive result. EMB was performed in cases of positive IMEG results and also at other times. Other noninvasive methods were used to help the diagnosis. Acute rejection (AR) was defined as international Society of Heart-Lung Transplantation grade Ilia or higher.Results We obtained 1231 IMEG records and 127 EMBs. Of the total 127 EMBs, 53 were positive, in which there were 42 IMEG positive results and 11 negative, while in the rest 74 negative EMBs, there were 9 IMEG positive results and 65 negative. The sensitivity of IMEG for the diagnosis of AR was 79.2%, and the specificity was 87.8%. The positive predictive value was 82.4% and the negative predictive value was 85.5%. Of the total of 1231 IMEG records, 51 were positive and 1180 were negative. Excluding 11 proved by EMB to be false negative, if the other 1169 were considered as no evidence of rejection, through the other noninvasive methods, AR diagnosed by this noninvasive monitoring strategy, the sensitivity was 79.2%, and the specificity was 99.2%. The positive predictive value was 82.4% and the negative predictive value was 99.1%. Conclusions IMEG can be used as a noninvasive method for

  7. THz radiation by beating Langmuir waves

    CERN Document Server

    Son, S; Park, J Y

    2013-01-01

    An intense terahertz (THz) radiation generated by the beating of two Langmuir waves, which are excited by the forward Raman scattering, is analyzed theoretically. The radiation energy per shot can be as high as 0.1 J, with the duration of 10 pico-second. Appropriate plasma density and the laser characteristics are examined.

  8. Beat the Instructor: An Introductory Forecasting Game

    Science.gov (United States)

    Snider, Brent R.; Eliasson, Janice B.

    2013-01-01

    This teaching brief describes a 30-minute game where student groups compete in-class in an introductory time-series forecasting exercise. The students are challenged to "beat the instructor" who competes using forecasting techniques that will be subsequently taught. All forecasts are graphed prior to revealing the randomly generated…

  9. Mechanical communication in cardiac cell synchronized beating

    Science.gov (United States)

    Nitsan, Ido; Drori, Stavit; Lewis, Yair E.; Cohen, Shlomi; Tzlil, Shelly

    2016-05-01

    Cell-cell communication, which enables cells to coordinate their activity and is essential for growth, development and function, is usually ascribed a chemical or electrical origin. However, cells can exert forces and respond to environment elasticity and to mechanical deformations created by their neighbours. The extent to which this mechanosensing ability facilitates intercellular communication remains unclear. Here we demonstrate mechanical communication between cells directly for the first time, providing evidence for a long-range interaction that induces long-lasting alterations in interacting cells. We show that an isolated cardiac cell can be trained to beat at a given frequency by mechanically stimulating the underlying substrate. Deformations are induced using an oscillatory mechanical probe that mimics the deformations generated by a beating neighbouring cardiac cell. Unlike electrical field stimulation, the probe-induced beating rate is maintained by the cell for an hour after the stimulation stops, implying that long-term modifications occur within the cell. These long-term alterations provide a mechanism for cells that communicate mechanically to be less variable in their electromechanical delay. Mechanical coupling between cells therefore ensures that the final outcome of action potential pacing is synchronized beating. We further show that the contractile machinery is essential for mechanical communication.

  10. Beat the Instructor: An Introductory Forecasting Game

    Science.gov (United States)

    Snider, Brent R.; Eliasson, Janice B.

    2013-01-01

    This teaching brief describes a 30-minute game where student groups compete in-class in an introductory time-series forecasting exercise. The students are challenged to "beat the instructor" who competes using forecasting techniques that will be subsequently taught. All forecasts are graphed prior to revealing the randomly generated…

  11. Atrial fibrillation detection by heart rate variability in Poincare plot

    Directory of Open Access Journals (Sweden)

    Jeon Moongu

    2009-12-01

    Full Text Available Abstract Background Atrial fibrillation (AFib is one of the prominent causes of stroke, and its risk increases with age. We need to detect AFib correctly as early as possible to avoid medical disaster because it is likely to proceed into a more serious form in short time. If we can make a portable AFib monitoring system, it will be helpful to many old people because we cannot predict when a patient will have a spasm of AFib. Methods We analyzed heart beat variability from inter-beat intervals obtained by a wavelet-based detector. We made a Poincare plot using the inter-beat intervals. By analyzing the plot, we extracted three feature measures characterizing AFib and non-AFib: the number of clusters, mean stepping increment of inter-beat intervals, and dispersion of the points around a diagonal line in the plot. We divided distribution of the number of clusters into two and calculated mean value of the lower part by k-means clustering method. We classified data whose number of clusters is more than one and less than this mean value as non-AFib data. In the other case, we tried to discriminate AFib from non-AFib using support vector machine with the other feature measures: the mean stepping increment and dispersion of the points in the Poincare plot. Results We found that Poincare plot from non-AFib data showed some pattern, while the plot from AFib data showed irregularly irregular shape. In case of non-AFib data, the definite pattern in the plot manifested itself with some limited number of clusters or closely packed one cluster. In case of AFib data, the number of clusters in the plot was one or too many. We evaluated the accuracy using leave-one-out cross-validation. Mean sensitivity and mean specificity were 91.4% and 92.9% respectively. Conclusions Because pulse beats of ventricles are less likely to be influenced by baseline wandering and noise, we used the inter-beat intervals to diagnose AFib. We visually displayed regularity of the inter-beat

  12. Study of myocardial cell inhomogeneity of the human heart: Simulation and validation using polarized light imaging.

    Science.gov (United States)

    Desrosiers, Paul Audain; Michalowicz, Gabrielle; Jouk, Pierre-Simon; Usson, Yves; Zhu, Yuemin

    2016-05-01

    The arrangement or architecture of myocardial cells plays a fundamental role in the heart's function and its change was shown to be directly linked to heart diseases. Inhomogeneity level is an important index of myocardial cell arrangements in the human heart. The authors propose to investigate the inhomogeneity level of myocardial cells using polarized light imaging simulations and experiments. The idea is based on the fact that the myosin filaments in myocardial cells have the same properties as those of a uniaxial birefringent crystal. The method then consists in modeling the myosin filaments of myocardial cells as uniaxial birefringent crystal, simulating the behavior of the latter by means of the Mueller matrix, and measuring the final intensity of polarized light and consequently the inhomogeneity level of myocardial cells in each voxel through the use of crossed polarizers. The method was evaluated on both simulated and real tissues and under various myocardial cell configurations including parallel cells, crossed cells, and cells with random orientations. When myocardial cells run perfectly parallel to each other, all the polarized light was blocked by those parallel myocardial cells, and a high homogeneity level was observed. However, if myocardial cells were not parallel to each other, some leakage of the polarized light was observed, thus causing the decrease of the polarized light amplitude and homogeneity level. The greater the crossing angle between myocardial cells, the smaller the amplitude of the polarized light and the greater the inhomogeneity level. For two populations of myocardial cell crossing at an angle, the resulting azimuth angle of the voxel was the bisector of this angle. Moreover, the value of the inhomogeneity level began to decrease from a nonzero value when the voxel was not totally homogeneous, containing for example cell crossing. The proposed method enables the physical information of myocardial tissues to be estimated and the

  13. Beat Noise Limitation in Coherent Time-Spreading OCDMA Network

    Institute of Scientific and Technical Information of China (English)

    Ken-ichi; Kitayama; Koji; Mutsushima

    2003-01-01

    The BER performance of the coherent time-spreading OCDMA network is analyzed by considering the MAI and beat noises as well as the other additive noises. The influence and solution for the beat noise issue are discussed.

  14. Mitochondrial structure and function are not different between nonfailing donor and end-stage failing human hearts.

    Science.gov (United States)

    Holzem, Katherine M; Vinnakota, Kalyan C; Ravikumar, Vinod K; Madden, Eli J; Ewald, Gregory A; Dikranian, Krikor; Beard, Daniel A; Efimov, Igor R

    2016-08-01

    During human heart failure, the balance of cardiac energy use switches from predominantly fatty acids (FAs) to glucose. We hypothesized that this substrate shift was the result of mitochondrial degeneration; therefore, we examined mitochondrial oxidation and ultrastructure in the failing human heart by using respirometry, transmission electron microscopy, and gene expression studies of demographically matched donor and failing human heart left ventricular (LV) tissues. Surprisingly, respiratory capacities for failing LV isolated mitochondria (n = 9) were not significantly diminished compared with donor LV isolated mitochondria (n = 7) for glycolysis (pyruvate + malate)- or FA (palmitoylcarnitine)-derived substrates, and mitochondrial densities, assessed via citrate synthase activity, were consistent between groups. Transmission electron microscopy images also showed no ultrastructural remodeling for failing vs. donor mitochondria; however, the fraction of lipid droplets (LDs) in direct contact with a mitochondrion was reduced, and the average distance between an LD and its nearest neighboring mitochondrion was increased. Analysis of FA processing gene expression between donor and failing LVs revealed 0.64-fold reduced transcript levels for the mitochondrial-LD tether, perilipin 5, in the failing myocardium (P = 0.003). Thus, reduced FA use in heart failure may result from improper delivery, potentially via decreased perilipin 5 expression and mitochondrial-LD tethering, and not from intrinsic mitochondrial dysfunction.-Holzem, K. M., Vinnakota, K. C., Ravikumar, V. K., Madden, E. J., Ewald, G. A., Dikranian, K., Beard, D. A., Efimov, I. R. Mitochondrial structure and function are not different between nonfailing donor and end-stage failing human hearts.

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

    OpenAIRE

    Leila Chaieb; Elke C. Wilpert; Christian Hoppe; Nikolai Axmacher; Juergen Fell

    2017-01-01

    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 ...

  16. Application of Nexfin noninvasive beat-to-beat arterial blood pressure monitoring in autonomic function testing.

    Science.gov (United States)

    Sipkens, Laura M; Treskes, Kaij; Ariese-Beldman, Karin; Veerman, Derk P; Boer, Christa

    2011-10-01

    Evaluation of autonomic function responses is increasingly important for risk prediction and hemodynamic evaluation in the ambulant and perioperative setting, but requires a noninvasive arterial blood pressure measurement device. This study describes whether a novel noninvasive beat-to-beat arterial blood pressure measurement device (Nexfin HD) is able to reproducibly reflect autonomic function responses in healthy volunteers. Noninvasive beat-to-beat arterial blood pressure measurements (Nexfin HD) were performed in 20 healthy men of 22 ± 3 years. Measurements were performed during supine steady state, controlled breathing (0.125 Hz), passive leg raising, a controlled Valsalva maneuver, and a quick stand test. Finally, relative changes in pulse pressure during autonomic function testing and the test-retest reproducibility were determined. Autonomic function tests induced beat-to-beat arterial blood pressure changes that were accurately monitored by the Nexfin device. The intraclass correlation coefficients for systolic and diastolic arterial blood pressure measurements during supine steady state were agreeable [0.91 (0.82-0.96) and 0.84 (0.69-0.93), respectively]. The reproducibility of blood pressure changes during controlled breathing, passive leg raising, and Valsalva maneuver averaged 0.92 (0.82-0.96), 0.76 (0.50-0.90), and 0.94 (0.89-0.97), respectively. The reproducibility of the pulse pressure variation (PPV) as calculated from controlled breathing-induced changes in the arterial blood pressure (13 ± 5%) was high [0.96 (0.93-0.98)]. This study shows that noninvasive beat-to-beat Nexfin HD arterial blood pressure measurements reproducibly reflect autonomic function responses in healthy volunteers.

  17. In time with rhythms : beat perception and sensorimotor synchronisation

    NARCIS (Netherlands)

    Schlichting, Nadine

    2015-01-01

    Music and beat perception are strongly connected to movement, a phenomenon known as sensorimotor synchronisation. Neurophysiologically, simple metronome-like beat sounds entrain neural oscillations, so that the brain oscillates with the same frequency as the beat frequency. The usefulness of being

  18. In time with rhythms : beat perception and sensorimotor synchronisation

    NARCIS (Netherlands)

    Schlichting, Nadine

    2015-01-01

    Music and beat perception are strongly connected to movement, a phenomenon known as sensorimotor synchronisation. Neurophysiologically, simple metronome-like beat sounds entrain neural oscillations, so that the brain oscillates with the same frequency as the beat frequency. The usefulness of being e

  19. 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…

  20. Altered expression of mitochondrial and extracellular matrix genes in the heart of human fetuses with chromosome 21 trisomy

    Directory of Open Access Journals (Sweden)

    Olla Carlo

    2007-08-01

    Full Text Available Abstract Background The Down syndrome phenotype has been attributed to overexpression of chromosome 21 (Hsa21 genes. However, the expression profile of Hsa21 genes in trisomic human subjects as well as their effects on genes located on different chromosomes are largely unknown. Using oligonucleotide microarrays we compared the gene expression profiles of hearts of human fetuses with and without Hsa21 trisomy. Results Approximately half of the 15,000 genes examined (87 of the 168 genes on Hsa21 were expressed in the heart at 18–22 weeks of gestation. Hsa21 gene expression was globally upregulated 1.5 fold in trisomic samples. However, not all genes were equally dysregulated and 25 genes were not upregulated at all. Genes located on other chromosomes were also significantly dysregulated. Functional class scoring and gene set enrichment analyses of 473 genes, differentially expressed between trisomic and non-trisomic hearts, revealed downregulation of genes encoding mitochondrial enzymes and upregulation of genes encoding extracellular matrix proteins. There were no significant differences between trisomic fetuses with and without heart defects. Conclusion We conclude that dosage-dependent upregulation of Hsa21 genes causes dysregulation of the genes responsible for mitochondrial function and for the extracellular matrix organization in the fetal heart of trisomic subjects. These alterations might be harbingers of the heart defects associated with Hsa21 trisomy, which could be based on elusive mechanisms involving genetic variability, environmental factors and/or stochastic events.

  1. Ischemic heart disease down-regulates angiotensin type 1 receptor mRNA in human coronary arteries

    DEFF Research Database (Denmark)

    Wackenfors, Angelica; Emilson, Malin; Ingemansson, Richard;

    2004-01-01

    Angiotensin II is important in the development of cardiovascular disease. In the present study, angiotensin II receptor mRNA levels were quantified by real-time polymerase chain reaction (real-time PCR) in human coronary arteries from patients with ischemic heart disease and controls. Furthermore......, the suitability of artery culture for studying angiotensin receptor changes was evaluated by in vitro pharmacology and real-time PCR. The angiotensin type 1 (AT1) receptor mRNA levels were down-regulated in human coronary arteries from patients with ischemic heart disease as compared to controls (P

  2. Cardiomyocyte Clusters Derived from Human Embryonic Stem Cells Share Similarities with Human Heart Tissue

    Institute of Scientific and Technical Information of China (English)

    Julia Asp; Daniella Steel; Marianne Jonsson; Caroline Améen; Kerstin Dahlenborg; Anders Jeppsson; Anders Lindahl; Peter Sartipy

    2010-01-01

    @@ Cardiotoxicity testing is a key activity in the pharmaceutical industry in order to detect detrimental effects of new drugs.A reliable human in vitro model would both be beneficial in selection of lead compounds and be important for reducing animal experimentation.

  3. Assessment of Mitochondrial Dysfunction and Monoamine Oxidase Contribution to Oxidative Stress in Human Diabetic Hearts

    Directory of Open Access Journals (Sweden)

    O. M. Duicu

    2016-01-01

    Full Text Available Mitochondria-related oxidative stress is a pathomechanism causally linked to coronary heart disease (CHD and diabetes mellitus (DM. Recently, mitochondrial monoamine oxidases (MAOs have emerged as novel sources of oxidative stress in the cardiovascular system and experimental diabetes. The present study was purported to assess the mitochondrial impairment and the contribution of MAOs-related oxidative stress to the cardiovascular dysfunction in coronary patients with/without DM. Right atrial appendages were obtained from 75 patients randomized into 3 groups: (1 Control (CTRL, valvular patients without CHD; (2 CHD, patients with confirmed CHD; and (3 CHD-DM, patients with CHD and DM. Mitochondrial respiration was measured by high-resolution respirometry and MAOs expression was evaluated by RT-PCR and immunohistochemistry. Hydrogen peroxide (H2O2 emission was assessed by confocal microscopy and spectrophotometrically. The impairment of mitochondrial respiration was substrate-independent in CHD-DM group. MAOs expression was comparable among the groups, with the predominance of MAO-B isoform but no significant differences regarding oxidative stress were detected by either method. Incubation of atrial samples with MAOs inhibitors significantly reduced the H2O2 in all groups. In conclusion, abnormal mitochondrial respiration occurs in CHD and is more severe in DM and MAOs contribute to oxidative stress in human diseased hearts with/without DM.

  4. [The function of the heart changes in implementation of the diving reactions in humans].

    Science.gov (United States)

    Baranova, T I; Berlov, D N; Zavarina, L B; Minigalin, A D; Smith, N Y; Xu, S; Yanvareva, I N

    2015-03-01

    The changes of chronotropic function of the heart and of the myocardium in the implementation of the diving response in humans were studied by the electrocardiographic method. The study involved 80 students aged 18-20 years. Diving simulation was performed by immersing the face in cold water during breath-hold exhale. When the water temperature was 12.3 +/- 2.3 degrees C, average duration of apnea was 31 +/- 11 s. The oxygen content in the exhaled air after apnea was 98.8 +/- 8.7 mm Hg, carbon dioxide--49.1 +/- 3.5 mm Hg. It was observed slowing of the heart rate, mainly due to the increasing of diastole in 41 of the 80 surveyed during simulating diving. But it also can be observed symptoms of conduction deterioration: atrioventricular block type I (22% of reactive type and 29% of the highly reactive type subjects), and exceeds standards QTc-interval prolongation (at 7.5% of the subjects). These responses are adaptive in nature and disappear in the recovery process. But the fact abnormalities of conduction in the myocardium must be considered when using the diving reflex in medical practice, as may be due to a predisposition to a certain pathology of the cardiovascular system.

  5. AN ANATOMICAL STUDY OF CORONARY ARTERY DOMINANCE IN HUMAN CADAVERIC HEARTS

    Directory of Open Access Journals (Sweden)

    Natasha

    2015-07-01

    Full Text Available CONTEXT: With ever increasing incidence of coronary heart disease, a thorough study of the coronary arteries is the need of time. AIM: The aim of the present study is to evaluate the coronary dominance pattern which will help the cardiac physicians and surgeons for better diagnosis and management of coronary arte ry disease. MATERIALS AND METHODS: The study undertaken in the Department of Anatomy, Assam Medical College included 75 perinatal and 15 adult cadaveric human hearts which were preserved in 10% formaldehyde solution after simple dissecting procedure and the dominance was noted. RESULTS: In the present study, out of total of 90 cases the right coronary dominance was found to be present in 58 cases (64.44%.This included 34(60.71% males and 24(70.59% females. Total cases of left coronary dominance were fo und to be 22(24.45%. Among these, 15(26.79% were males and 7(20.59% were females. Finally 10(11.11% co - dominant cases were found, of which 7 cases (12.50% were males and 3 cases (8.82% were females. CONCLUSION : Thus the study revealed that most of th e cases were having right coronary predominance. KEYWORDS : Coronary arteries, Dominance .

  6. Inhalation of ultrafine carbon particles alters heart rate and heart rate variability in people with type 2 diabetes.

    Science.gov (United States)

    Vora, Rathin; Zareba, Wojciech; Utell, Mark J; Pietropaoli, Anthony P; Chalupa, David; Little, Erika L; Oakes, David; Bausch, Jan; Wiltshire, Jelani; Frampton, Mark W

    2014-07-16

    Diabetes may confer an increased risk for the cardiovascular health effects of particulate air pollution, but few human clinical studies of air pollution have included people with diabetes. Ultrafine particles (UFP, ≤100 nm in diameter) have been hypothesized to be an important component of particulate air pollution with regard to cardiovascular health effects. 17 never-smoker subjects 30-60 years of age, with stable type 2 diabetes but otherwise healthy, inhaled either filtered air (0-10 particles/cm3) or elemental carbon UFP (~107 particles/cm3, ~50 ug/m3, count median diameter 32 nm) by mouthpiece, for 2 hours at rest, in a double-blind, randomized, crossover study design. A digital 12-lead electrocardiogram (ECG) was recorded continuously for 48 hours, beginning 1 hour prior to exposure. Analysis of 5-minute segments of the ECG during quiet rest showed reduced high-frequency heart rate variability with UFP relative to air exposure (p = 0.014), paralleled by non-significant reductions in time-domain heart rate variability parameters. In the analysis of longer durations of the ECG, we found that UFP exposure increased the heart rate relative to air exposure. During the 21- to 45-hour interval after exposure, the average heart rate increased approximately 8 beats per minute with UFP, compared to 5 beats per minute with air (p = 0.045). There were no UFP effects on cardiac rhythm or repolarization. Inhalation of elemental carbon ultrafine particles alters heart rate and heart rate variability in people with type 2 diabetes. Our findings suggest that effects may occur and persist hours after a single 2-hour exposure.

  7. P2 receptors in human heart: upregulation of P2X6 in patients undergoing heart transplantation, interaction with TNFalpha and potential role in myocardial cell death.

    Science.gov (United States)

    Banfi, Cristina; Ferrario, Silvia; De Vincenti, Ombretta; Ceruti, Stefania; Fumagalli, Marta; Mazzola, Alessia; D' Ambrosi, Nadia; Volontè, Cinzia; Fratto, Pasquale; Vitali, Ettore; Burnstock, Geoffrey; Beltrami, Elena; Parolari, Alessandro; Polvani, GianLuca; Biglioli, Paolo; Tremoli, Elena; Abbracchio, Maria P

    2005-12-01

    ATP acts as a neurotransmitter via seven P2X receptor-channels for Na(+) and Ca(2+), and eight G-protein-coupled P2Y receptors. Despite evidence suggesting roles in human heart, the map of myocardial P2 receptors is incomplete, and their involvement in chronic heart failure (CHF) has never received adequate attention. In left myocardia from five to nine control and 5-12 CHF subjects undergoing heart transplantation, we analyzed the full repertoire of P2 receptors and of 10 "orphan" P2Y-like receptors. All known P2Y receptors (i.e. P2Y(1,2,4,6,11,12,13,14)) and two P2Y-like receptors (GPR91 and GPR17) were detected in all subjects. All known P2X(1-7) receptors were also detected; of these, only P2X(6) was upregulated in CHF, as confirmed by quantitative real time-PCR. The potential significance of this change was studied in primary cardiac fibroblasts freshly isolated from young pigs. Exposure of cardiac fibroblasts to ATP or its hydrolysis-resistant-analog benzoylATP induced apoptosis. TNFalpha (a cytokine implicated in CHF progression) exacerbated cell death. Similar effects were induced by ATP and TNFalpha in a murine cardiomyocytic cell line. In cardiac fibroblasts, TNFalpha inhibited the downregulation of P2X(6) mRNA associated to prolonged agonist exposure, suggesting that, by preventing ATP-induced P2X(6) desensitization, TNFalpha may abolish a defense mechanism meant at avoiding Ca(2+) overload and, ultimately, Ca(2+)-dependent cell death. This may provide a basis for P2X(6) upregulation in CHF. In conclusion, we provide the first characterization of P2 receptors in the human heart and suggest that the interaction between TNFalpha and the upregulated P2X(6) receptor may represent a novel pathogenic mechanism in CHF.

  8. Direct hydrogel encapsulation of pluripotent stem cells enables ontomimetic differentiation and growth of engineered human heart tissues.

    Science.gov (United States)

    Kerscher, Petra; Turnbull, Irene C; Hodge, Alexander J; Kim, Joonyul; Seliktar, Dror; Easley, Christopher J; Costa, Kevin D; Lipke, Elizabeth A

    2016-03-01

    Human engineered heart tissues have potential to revolutionize cardiac development research, drug-testing, and treatment of heart disease; however, implementation is limited by the need to use pre-differentiated cardiomyocytes (CMs). Here we show that by providing a 3D poly(ethylene glycol)-fibrinogen hydrogel microenvironment, we can directly differentiate human pluripotent stem cells (hPSCs) into contracting heart tissues. Our straight-forward, ontomimetic approach, imitating the process of development, requires only a single cell-handling step, provides reproducible results for a range of tested geometries and size scales, and overcomes inherent limitations in cell maintenance and maturation, while achieving high yields of CMs with developmentally appropriate temporal changes in gene expression. We demonstrate that hPSCs encapsulated within this biomimetic 3D hydrogel microenvironment develop into functional cardiac tissues composed of self-aligned CMs with evidence of ultrastructural maturation, mimicking heart development, and enabling investigation of disease mechanisms and screening of compounds on developing human heart tissue.

  9. 3D reconstruction of a human heart fascicle using SurfDriver

    Science.gov (United States)

    Rader, Robert J.; Phillips, Steven J.; LaFollette, Paul S., Jr.

    2000-06-01

    The Temple University Medical School has a sequence of over 400 serial sections of adult normal ventricular human heart tissue, cut at 25 micrometer thickness. We used a Zeiss Ultraphot with a 4x planapo objective and a Pixera digital camera to make a series of 45 sequential montages to use in the 3D reconstruction of a fascicle (muscle bundle). We wrote custom software to merge 4 smaller image fields from each section into one composite image. We used SurfDriver software, developed by Scott Lozanoff of the University of Hawaii and David Moody of the University of Alberta, for registration, object boundary identification, and 3D surface reconstruction. We used an Epson Stylus Color 900 printer to get photo-quality prints. We describe the challenge and our solution to the following problems: image acquisition and digitization, image merge, alignment and registration, boundary identification, 3D surface reconstruction, 3D visualization and orientation, snapshot, and photo-quality prints.

  10. 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.

  11. 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.

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

    Science.gov (United States)

    Chaieb, Leila; Wilpert, Elke C; Hoppe, Christian; Axmacher, Nikolai; Fell, Juergen

    2017-01-01

    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.

  13. 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.

  14. 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. PMID:25452734

  15. Serelaxin, recombinant human relaxin-2, for treatment of acute heart failure (RELAX-AHF) : a randomised, placebo-controlled trial

    NARCIS (Netherlands)

    Teerlink, John R.; Cotter, Gad; Davison, Beth A.; Felker, G. Michael; Filippatos, Gerasimos; Greenberg, Barry H.; Ponikowski, Piotr; Unemori, Elaine; Voors, Adriaan A.; Adams, Kirkwood F.; Dorobantu, Maria I.; Grinfeld, Liliana R.; Jondeau, Guillaume; Marmor, Alon; Masip, Josep; Pang, Peter S.; Werdan, Karl; Teichman, Sam L.; Trapani, Angelo; Bush, Christopher A.; Saini, Rajnish; Schumacher, Christoph; Severin, Thomas M.; Metra, Marco

    2013-01-01

    Background Serelaxin, recombinant human relaxin-2, is a vasoactive peptide hormone with many biological and haemodynamic effects. In a pilot study, serelaxin was safe and well tolerated with positive clinical outcome signals in patients with acute heart failure. The RELAX-AHF trial tested the hypoth

  16. The acute effects of intravenously administered mibefradil, a new calcium antagonist, on the electrophysiologic characteristics of the human heart

    NARCIS (Netherlands)

    Rosenquist, M; BrembillaPerrot, B; Meinertz, T; Neugebauer, A; Crijns, HJMG; Smeets, JLRM; vanderVring, JAFM; Fromer, M; Kobrin, [No Value

    1997-01-01

    Objective: This multicenter, double-blind, placebo-controlled, parallel-group study was designed to assess the acute effects of intravenous mibefradil on the electrophysiologic characteristics of the human heart. Methods: Seventy-one patients referred for routine electrophysiologic testing were rand

  17. Serelaxin, recombinant human relaxin-2, for treatment of acute heart failure (RELAX-AHF) : a randomised, placebo-controlled trial

    NARCIS (Netherlands)

    Teerlink, John R.; Cotter, Gad; Davison, Beth A.; Felker, G. Michael; Filippatos, Gerasimos; Greenberg, Barry H.; Ponikowski, Piotr; Unemori, Elaine; Voors, Adriaan A.; Adams, Kirkwood F.; Dorobantu, Maria I.; Grinfeld, Liliana R.; Jondeau, Guillaume; Marmor, Alon; Masip, Josep; Pang, Peter S.; Werdan, Karl; Teichman, Sam L.; Trapani, Angelo; Bush, Christopher A.; Saini, Rajnish; Schumacher, Christoph; Severin, Thomas M.; Metra, Marco

    2013-01-01

    Background Serelaxin, recombinant human relaxin-2, is a vasoactive peptide hormone with many biological and haemodynamic effects. In a pilot study, serelaxin was safe and well tolerated with positive clinical outcome signals in patients with acute heart failure. The RELAX-AHF trial tested the hypoth

  18. Cortical evoked potentials to an auditory illusion: binaural beats.

    Science.gov (United States)

    Pratt, Hillel; Starr, Arnold; Michalewski, Henry J; Dimitrijevic, Andrew; Bleich, Naomi; Mittelman, Nomi

    2009-08-01

    To define brain activity corresponding to an auditory illusion of 3 and 6Hz binaural beats in 250Hz or 1000Hz base frequencies, and compare it to the sound onset response. Event-Related Potentials (ERPs) were recorded in response to unmodulated tones of 250 or 1000Hz to one ear and 3 or 6Hz higher to the other, creating an illusion of amplitude modulations (beats) of 3Hz and 6Hz, in base frequencies of 250Hz and 1000Hz. Tones were 2000ms in duration and presented with approximately 1s intervals. Latency, amplitude and source current density estimates of ERP components to tone onset and subsequent beats-evoked oscillations were determined and compared across beat frequencies with both base frequencies. All stimuli evoked tone-onset P(50), N(100) and P(200) components followed by oscillations corresponding to the beat frequency, and a subsequent tone-offset complex. Beats-evoked oscillations were higher in amplitude with the low base frequency and to the low beat frequency. Sources of the beats-evoked oscillations across all stimulus conditions located mostly to left lateral and inferior temporal lobe areas in all stimulus conditions. Onset-evoked components were not different across stimulus conditions; P(50) had significantly different sources than the beats-evoked oscillations; and N(100) and P(200) sources located to the same temporal lobe regions as beats-evoked oscillations, but were bilateral and also included frontal and parietal contributions. Neural activity with slightly different volley frequencies from left and right ear converges and interacts in the central auditory brainstem pathways to generate beats of neural activity to modulate activities in the left temporal lobe, giving rise to the illusion of binaural beats. Cortical potentials recorded to binaural beats are distinct from onset responses. Brain activity corresponding to an auditory illusion of low frequency beats can be recorded from the scalp.

  19. Artificial Heart Fluid Dynamics.

    Science.gov (United States)

    Mussivand, Tofigh Varcaneh

    Flow characteristics within pneumatic, pulsatile, and pusher plate prosthetic hearts were studied. The blood pumps evaluated were duplicates of pumps used for in vivo calf and for clinical implantation at the Cleveland Clinic Foundation. Human dura mater bioprosthetic, caged disk, and Bjork-Shiley tilting disk valves were employed in the pumps. Dual camera video tape and synchronized still photography were used to study flow patterns. Diffused light and a planar laser source provided illumination. The laser light was fanned into a plane with a thickness of 0.2 mm to 10 mm. Magnesium oxide and Amberlite particles were used as tracers. Aqueous-glycerol, aqueous-sucrose solutions and mineral oil were used as blood analog fluids. Inflow, outflow, drive, and afterload pressures, diaphragm motion, cardiac output, and heart rate were measured and recorded. An electrical circuit was developed to synchronize pump diaphragm motion with captured images of flow trajectories. After digitizing the trajectories, velocities, global and local turbulence, and shear stresses were obtained. Disturbed and recirculating zones were identified. Qualitative and quantitative analyses were performed using data obtained from the digitization of flow trajectories. Simultaneous turbulence and stasis were observed during most phases of the cardiac cycles in all the pumps tested. A maximum Reynold's shear stress of 2889 dynes/cm ^2 occurred at 120 beats per minute (bpm). The peak velocity was 146 cm/sec during systole. The identified regions of recirculation, low velocity and disturbed flow were shown to correlate with thrombosed areas of explanted blood pumps. The maximum calculated turbulence intensity was 106 cm/sec which occurred at 120 bpm during systole.

  20. Cardiac remodeling as a consequence of atrial fibrillation: An anatomical study of perfusion-fixed human heart specimens

    Institute of Scientific and Technical Information of China (English)

    Christopher D Rolfes; Stephen A Howard; Ryan P Goff; Paul A Iaizzo

    2011-01-01

    Background Atrial fibrillation(AF)causes a continuum of atrial anatomical remodeling.Methods Using a library of perfusion-fixed human hearts,specimens with AF were compared to controls.During this preliminary assessment study,direct measurements were taken of atrial volume,pulmonary vein(PV)circumference,and left atrial(LA)wall thicknesses.Results Hearts with AF typically had larger atrial volumes,as well as a much larger variation in volume compared to controls(range of 59.6-227.1 mL in AF hearts compared to 65.1-115.9 mL in controls).For all hearts,right PVs were larger than left PVs(mean: 171.4±84.6 mm' for right and 118.2±50.1 mm2 for left P<0.005).LA wall thicknesses ranged from 0.7 mm to 3.1 min for both AF and control hearts.Conclusions Hearts with AF had a large range of sizes which is consistent with the progression of atrial remodeling during AF.The large range of thicknesses will influence the amount of energy needed to create transmural lesions during ablation procedures.

  1. Beat-Frequency/Microsphere Medical Ultrasonic Imaging

    Science.gov (United States)

    Yost, William T.; Cantrell, John H.; Pretlow, Robert A., III

    1995-01-01

    Medical ultrasonic imaging system designed to provide quantitative data on various flows of blood in chambers, blood vessels, muscles, and tissues of heart. Sensitive enough to yield readings on flows of blood in heart even when microspheres used as ultrasonic contrast agents injected far from heart and diluted by circulation of blood elsewhere in body.

  2. Profile of Heart Donors from the Human Valve Bank of the Santa Casa de Misericórdia de Curitiba.

    Science.gov (United States)

    Ferreira, Renata Maria; Costa, Marise Teresinha Brenner Affonso da; Canciglieri Junior, Osiris; Sant'Anna, Ângelo Márcio Oliveira

    2016-04-01

    Human heart valves are used as replacement valves and have satisfactory functional results compared with conventional prostheses. Characterize the profile of effective heart donors from the human valve bank of the santa casa de misericórdia de curitiba and analyze the association between the profile variables. It consists of a retrospective and quantitative study of electronic medical records from heart donors for heart valves. every heart donation made to the bank between january 2004 and december 2014 was studied. 2,149 donations were analyzed, from donors aged 0 to 71 years old, with an average of 34.9 ± 15.03 years old. most donors were male 65.7% (n=1,411) and 34.3% (n=738) were female. among the most frequent causes of the donors' death are trauma at 53% (n=1,139) and cerebral vascular accident at 34.2% (n=735). there was significant statistical association between the analyzed variables. There has been an improvement in brazil's donation rate, being essential that the tissue banks work together with the state and federal district centers for notification, procurement and distribution of organs in order to increase the number of donors.

  3. CONSUMPTION OF SATURATED ANIMAL FATS IN THE DIET OF HUMANS MAY DECREASE THE RATE OF HEART DISEASE IN THE FUTURE

    OpenAIRE

    Soroush Niknamian; Mehrandokht Nekavand

    2017-01-01

    Fats, as part of the human dietary regime are a concentrated source of energy. Animals contain saturated and plants contain unsaturated type of fatty acids. In this prospective research, the role of animal saturated fatty acids is highlighted and is proven to be a rational dietary source for the human diet. Saturated fats consumption is a wise choice in order to reduce the coronary heart disease risk, although it is believed in an opposite way. Researching through the healthiest tribes and kn...

  4. Simulation and mechanistic investigation of the arrhythmogenic role of the late sodium current in human heart failure.

    Directory of Open Access Journals (Sweden)

    Beatriz Trenor

    Full Text Available Heart failure constitutes a major public health problem worldwide. The electrophysiological remodeling of failing hearts sets the stage for malignant arrhythmias, in which the role of the late Na(+ current (I(NaL is relevant and is currently under investigation. In this study we examined the role of I(NaL in the electrophysiological phenotype of ventricular myocytes, and its proarrhythmic effects in the failing heart. A model for cellular heart failure was proposed using a modified version of Grandi et al. model for human ventricular action potential that incorporates the formulation of I(NaL. A sensitivity analysis of the model was performed and simulations of the pathological electrical activity of the cell were conducted. The proposed model for the human I(NaL and the electrophysiological remodeling of myocytes from failing hearts accurately reproduce experimental observations. The sensitivity analysis of the modulation of electrophysiological parameters of myocytes from failing hearts due to ion channels remodeling, revealed a role for I(NaL in the prolongation of action potential duration (APD, triangulation of the shape of the AP, and changes in Ca(2+ transient. A mechanistic investigation of intracellular Na(+ accumulation and APD shortening with increasing frequency of stimulation of failing myocytes revealed a role for the Na(+/K(+ pump, the Na(+/Ca(2+ exchanger and I(NaL. The results of the simulations also showed that in failing myocytes, the enhancement of I(NaL increased the reverse rate-dependent APD prolongation and the probability of initiating early afterdepolarizations. The electrophysiological remodeling of failing hearts and especially the enhancement of the I(NaL prolong APD and alter Ca(2+ transient facilitating the development of early afterdepolarizations. An enhanced I(NaL appears to be an important contributor to the electrophysiological phenotype and to the dysregulation of [Ca(2+](i homeostasis of failing myocytes.

  5. 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.

  6. The failing human heart is unable to use the Frank-Starling mechanism.

    Science.gov (United States)

    Schwinger, R H; Böhm, M; Koch, A; Schmidt, U; Morano, I; Eissner, H J; Uberfuhr, P; Reichart, B; Erdmann, E

    1994-05-01

    There is evidence that the failing human left ventricle in vivo subjected to additional preload is unable to use the Frank-Starling mechanism. The present study compared the force-tension relation in human nonfailing and terminally failing (heart transplants required because of dilated cardiomyopathy) myocardium. Isometric force of contraction of electrically driven left ventricular papillary muscle strips was studied under various preload conditions (2 to 20 mN). To investigate the influence of inotropic stimulation, the force-tension relation was studied in the presence of the cardiac glycoside ouabain. In skinned-fiber preparations of the left ventricle, developed tension was measured after stretching the preparations to 150% of the resting length. To evaluate the length-dependent activation of cardiac myofibrils by Ca2+ in failing and nonfailing myocardium, the tension-Ca2+ relations were also measured. After an increase of preload, the force of contraction gradually increased in nonfailing myocardium but was unchanged in failing myocardium. There were no differences in resting tension, muscle length, or cross-sectional area of the muscles between both groups. Pretreatment with ouabain (0.02 mumol/L) restored the force-tension relation in failing myocardium and preserved the force-tension relation in nonfailing tissue. In skinned-fiber preparations of the same hearts, developed tension increased significantly after stretching only in preparations from nonfailing but not from failing myocardium. The Ca2+ sensitivity of skinned fibers was significantly higher in failing myocardium (EC50, 1.0; 95% confidence limit, 0.88 to 1.21 mumol/L) compared with nonfailing myocardium (EC50, 1.7; 95% confidence limit, 1.55 to 1.86 mumol/L). After increasing the fiber length by stretching, a significant increase in the sensitivity of the myofibrils to Ca2+ was observed in nonfailing but not in failing myocardium. These experiments provide evidence for an impaired force

  7. Human engineered heart tissue as a model system for drug testing.

    Science.gov (United States)

    Eder, Alexandra; Vollert, Ingra; Hansen, Arne; Eschenhagen, Thomas

    2016-01-15

    Drug development is time- and cost-intensive and, despite extensive efforts, still hampered by the limited value of current preclinical test systems to predict side effects, including proarrhythmic and cardiotoxic effects in clinical practice. Part of the problem may be related to species-dependent differences in cardiomyocyte biology. Therefore, the event of readily available human induced pluripotent stem cell (hiPSC)-derived cardiomyocytes (CM) has raised hopes that this human test bed could improve preclinical safety pharmacology as well as drug discovery approaches. However, hiPSC-CM are immature and exhibit peculiarities in terms of ion channel function, gene expression, structural organization and functional responses to drugs that limit their present usefulness. Current efforts are thus directed towards improving hiPSC-CM maturity and high-content readouts. Culturing hiPSC-CM as 3-dimensional engineered heart tissue (EHT) improves CM maturity and anisotropy and, in a 24-well format using silicone racks, enables automated, multiplexed high content readout of contractile function. This review summarizes the principal technology and focuses on advantages and disadvantages of this technology and its potential for preclinical drug screening.

  8. Recellularization of biological heart valves with human vascular cells: in vitro hemocompatibility assessment.

    Science.gov (United States)

    Schopka, Simon; Schmid, Franz-Xaver; Hirt, Stephan; Birnbaum, Dietrich E; Schmid, Christof; Lehle, Karla

    2009-01-01

    Coverage of cardiovascular bioprostheses with autologous endothelium is used for the purpose of improving blood compatibility. The aim of our study was to analyze endothelialization potential of glutaraldehyde-fixed heart valves, cellular functions of seeded endothelial cells (EC), and the impact of a two-stage seeding protocol using human vascular fibroblasts (FB) and EC from saphenous veins (HSVEC) on cellular functional properties in vitro. Adherence and morphology of adhered cells were assessed by scanning electronic microscopy and immunohistochemistry. Reproducible, complete surface coverage with EC was established on decellularized and glutaraldehyde-fixed bovine pericardium. Analyzing functional properties of cells directly adhered to biomaterial revealed nonproliferative cells, which were capable of inflammatory stimulation in terms of TNF-induced increase in interleukin-6 secretion and adhesion of inflammatory cells. Furthermore, EC showed sustained antithrombotic properties quantified by platelet adhesion onto EC and prostacyclin secretion by EC. Preseeding with vascular fibroblasts using a two-stage seeding protocol induced EC proliferation and improved inflammatory and anti-thrombotic functions. Cardiovascular biomaterials differ significantly in their potential to allow for adhesion of human EC. Successfully endothelialized biomaterial, however, revealed cellular properties which are likely to be favorable to improving performance of biomaterials. Two-stage seeding adds regenerative potential and improves cell functions of adherent EC.

  9. Increased expression of fatty-acid and calcium metabolism genes in failing human heart.

    Directory of Open Access Journals (Sweden)

    Vanessa García-Rúa

    Full Text Available BACKGROUND: Heart failure (HF involves alterations in metabolism, but little is known about cardiomyopathy-(CM-specific or diabetes-independent alterations in gene expression of proteins involved in fatty-acid (FA uptake and oxidation or in calcium-(Ca(2+-handling in the human heart. METHODS: RT-qPCR was used to quantify mRNA expression and immunoblotting to confirm protein expression in left-ventricular myocardium from patients with HF (n = 36 without diabetes mellitus of ischaemic (ICM, n = 16 or dilated (DCM, n = 20 cardiomyopathy aetiology, and non-diseased donors (CTL, n = 6. RESULTS: Significant increases in mRNA of genes regulating FA uptake (CD36 and intracellular transport (Heart-FA-Binding Protein (HFABP were observed in HF patients vs CTL. Significance was maintained in DCM and confirmed at protein level, but not in ICM. mRNA was higher in DCM than ICM for peroxisome-proliferator-activated-receptor-alpha (PPARA, PPAR-gamma coactivator-1-alpha (PGC1A and CD36, and confirmed at the protein level for PPARA and CD36. Transcript and protein expression of Ca(2+-handling genes (Two-Pore-Channel 1 (TPCN1, Two-Pore-Channel 2 (TPCN2, and Inositol 1,4,5-triphosphate Receptor type-1 (IP3R1 increased in HF patients relative to CTL. Increases remained significant for TPCN2 in all groups but for TPCN1 only in DCM. There were correlations between FA metabolism and Ca(2+-handling genes expression. In ICM there were six correlations, all distinct from those found in CTL. In DCM there were also six (all also different from those found in CTL: three were common to and three distinct from ICM. CONCLUSION: DCM-specific increases were found in expression of several genes that regulate FA metabolism, which might help in the design of aetiology-specific metabolic therapies in HF. Ca(2+-handling genes TPCN1 and TPCN2 also showed increased expression in HF, while HF- and CM-specific positive correlations were found among several FA and Ca(2

  10. Elasticity-based determination of isovolumetric phases in the human heart

    Directory of Open Access Journals (Sweden)

    Braun Jürgen

    2010-10-01

    Full Text Available Abstract Background/Motivation To directly determine isovolumetric cardiac time intervals by magnetic resonance elastography (MRE using the magnitude of the complex signal for deducing morphological information combined with the phase of the complex signal for tension-relaxation measurements. Methods Thirty-five healthy volunteers and 11 patients with relaxation abnormalities were subjected to transthoracic wave stimulation using vibrations of approximately 25 Hz. A k-space-segmented, ECG-gated gradient-recalled echo steady-state sequence with a 500-Hz bipolar motion-encoding gradient was used for acquiring a series of 360 complex images of a short-axis view of the heart at a frame rate of less than 5.2 ms. Magnitude images were employed for measuring the cross-sectional area of the left ventricle, while phase images were used for analyzing the amplitudes of the externally induced waves. The delay between the decrease in amplitude and onset of ventricular contraction was determined in all subjects and assigned to the time of isovolumetric tension. Conversely, the delay between the increase in wave amplitude and ventricular dilatation was used for measuring the time of isovolumetric elasticity relaxation. Results Wave amplitudes decreased during systole and increased during diastole. The variation in wave amplitude occurred ahead of morphological changes. In healthy volunteers the time of isovolumetric elasticity relaxation was 75 ± 31 ms, which is significantly shorter than the time of isovolumetric tension of 136 ± 36 ms (P n = 11 isovolumetric elasticity relaxation was significantly prolonged, with 133 ± 57 ms (P P = 0.053. Conclusion The complex MRE signal conveys complementary information on cardiac morphology and elasticity, which can be combined for directly measuring isovolumetric tension and elasticity relaxation in the human heart.

  11. Noninvasive beat-to-beat finger arterial pressure monitoring during orthostasis: a comprehensive review of normal and abnormal responses at different ages.

    Science.gov (United States)

    van Wijnen, V K; Finucane, C; Harms, M P M; Nolan, H; Freeman, R L; Westerhof, B E; Kenny, R A; Ter Maaten, J C; Wieling, W

    2017-05-31

    Over the past 30 years, noninvasive beat-to-beat