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Heart failure (HF) is a complex clinical syndrome with multiple interactions between the failing myocardium and cerebral (dys-)functions. Bi-directional feedback interactions between the heart and the brain are inherent in the pathophysiology of HF: (i) the impaired cardiac function affects cerebral structure and functional capacity, and (ii) neuronal signals impact on the cardiovascular continuum. These interactions contribute to the symptomatic presentation of HF patients and affect many co-morbidities of HF. Moreover, neuro-cardiac feedback signals significantly promote aggravation and further progression of HF and are causal in the poor prognosis of HF. The diversity and complexity of heart and brain interactions make it difficult to develop a comprehensive overview. In this paper a systematic approach is proposed to develop a comprehensive atlas of related conditions, signals and disease mechanisms of the interactions between the heart and the brain in HF. The proposed taxonomy is based on pathophysiological principles. Impaired perfusion of the brain may represent one major category, with acute (cardio-embolic) or chronic (haemodynamic failure) low perfusion being sub-categories with mostly different consequences (i.e. ischaemic stroke or cognitive impairment, respectively). Further categories include impairment of higher cortical function (mood, cognition), f brain stem function (sympathetic over-activation, neuro-cardiac reflexes). Treatment-related interactions could be categorized as medical, interventional and device-related interactions. Also interactions due to specific diseases are categorized. A methodical approach to categorize the interdependency of heart and brain may help to integrate individual research areas into an overall picture. [ABSTRACT FROM AUTHOR]

The rapid growth in computational power, sensor technology, and wearable devices has provided a solid foundation for all aspects of cardiac arrhythmia care. Artificial intelligence (AI) has been instrumental in bringing about significant changes in the prevention, risk assessment, diagnosis, and treatment of arrhythmia. This review examines the current state of AI in the diagnosis and treatment of atrial fibrillation, supraventricular arrhythmia, ventricular arrhythmia, hereditary channelopathies, and cardiac pacing. Furthermore, ChatGPT, which has gained attention recently, is addressed in this paper along with its potential applications in the field of arrhythmia. Additionally, the accuracy of arrhythmia diagnosis can be improved by identifying electrode misplacement or erroneous swapping of electrode position using AI. Remote monitoring has expanded greatly due to the emergence of contactless monitoring technology as wearable devices continue to develop and flourish. Parallel advances in AI computing power, ChatGPT, availability of large data sets, and more have greatly expanded applications in arrhythmia diagnosis, risk assessment, and treatment. More precise algorithms based on big data, personalized risk assessment, telemedicine and mobile health, smart hardware and wearables, and the exploration of rare or complex types of arrhythmia are the future direction. [ABSTRACT FROM AUTHOR]

Exercise training (ET) and secondary prevention measures in cardiovascular disease aim to stimulate early physical activity and to facilitate recovery and improve health behaviours. ET has also been proposed for heart failure patients with a ventricular assist device (VAD), to help recovery in the patient's functional capacity. However, the existing evidence in support of ET in these patients remains limited. After a review of current knowledge on the causes of the persistence of limitation in exercise capacity in VAD recipients, and concerning the benefit of ET in VAD patients, the Heart Failure Association of the European Society of Cardiology has developed the present document to provide practical advice on implementing ET. This includes appropriate screening to avoid complications and then starting with early mobilisation, ET prescription is individualised to meet the patient's needs. Finally, gaps in our knowledge are discussed. [ABSTRACT FROM AUTHOR]

Mesenchymal stem cells (MSCs) treatment has been widely explored as a therapy for myocardial infarction, peripheral ischemic vascular diseases, dilated cardiomyopathy, and pulmonary hypertension. Latest in vitro studies suggest that MSCs can differentiate into contractile cardiomyocytes. One of the best‐characterized MSCs products are MSCs‐derived extracellular vesicles (EVs). EVs are crucial paracrine effectors of MSCs. Based on previous works, paracrine effects of MSCs play a primary role in the regenerative ability. Hence, in the current paper, we focused our attention on an alternative approach, exploiting products derived from human dental pulp stem cells (hDPSCs) rather than MSCs themselves, which may denote a cost‐effective and safer approach. The focus has been on EVs and the bioactive molecules they contain to evaluate their ability to influence the differentiation process toward cardiomyogenic lineage. The expression of GATA4, ACTC1, CX43, and Nkx2.5 was evaluated using Immunofluorescence, real time‐PCR, and Western blotting analyses. Furthermore, the expression profiling analysis of the microRNA hsa‐miR‐200c‐3p, targeting the GATA4 gene, was studied. The hsa‐miR‐200c‐3p was found significantly down‐regulated in both c‐hDPSCs + EVs‐hDPSCs and c‐hDPSCs + EVs‐HL‐1 compared to untreated c‐hDPSCs underlying a possible epigenetic mechanism behind the prevalent up‐regulation of its targeted GATA4 gene. The aim of the present work was to develop an in vitro model of hDPSCs able to differentiate into cardiomyocytes in order to investigate the role of EVs derived from hDPSCs and derived from HL‐1 cardiomyocyte cell line in modulating the differentiation process toward cardiomyogenic lineage. [ABSTRACT FROM AUTHOR]

In vitro reconstruction of highly mature engineered heart tissues (EHTs) is attempted for the selection of cardiotoxic drugs suitable for individual patients before administration. Mechanical contractile force generated in the EHTs is known to be a critical indicator for evaluating the EHT response. However, measuring contractile force requires anchoring the EHT in a tailored force‐sensing cell culture chamber, causing technical difficulties in the stable evaluation of contractile force in long‐term culture. This paper proposes a hydrogel‐sheathed human induced pluripotent stem cell (hiPSC)‐derived heart microtissue (H3M) that can provide an anchor‐free contractile force measurement platform in commonly used multi‐well plates. The contractile force associated with tissue formation and drug response is calculated by motion tracking and finite element analysis on the bending angle of the hydrogel sheath. From the experiment of the drug response, H3M is an excellent drug screening platform with high sensitivity and early testing capability compared to conventionally anchored EHT. This unique platform would be useful and versatile for regenerative therapy and drug discovery research in EHT. [ABSTRACT FROM AUTHOR]

For the effective diagnosis of cardio vascular disease (CVD), anatomical characteristics of the heart must be examined, which depends on segmenting the cardiac tissues of interest and then classifying them into appropriate pathological groups. In recent years, deep learning (DL)‐based computer aided design (CAD) segmentation has been employed to automate the segmentation process. Despite the evolution of several DL methods, they still fail due to the shape variation of the heart in patients and the availability of a limited amount of data. This paper proposes an effective Saliency and Active Contour‐based Attention UNet3+ algorithm to segment the ventricles of the heart, which is a challenging task for most researchers, especially with an irregularly shaped right ventricle (RV) that varies over cardiac phases. The algorithm outperforms other state‐of‐the‐art methods in DC metrics, which proves its efficiency in automating the segmentation process. [ABSTRACT FROM AUTHOR]

Despite the particular standards, technologies, and trends (W3C, RESTful, microservices, etc.) that a team decides to follow for the development of a service‐oriented system, most likely the team members will have to use one or more services that solve general‐purpose problems like cloud computing, networking and content delivery, storage and database, management and governance, and application integration. Typically, general‐purpose services are long‐lived, they have several responsibilities, their interfaces are complex, and they grow over time. The way that these services evolve also affects the evolution of any system that will depend on them. Consequently, the selection of the particular services that will be used is a main concern for the team. In this paper, we report a pattern, called the athletic heart syndrome, which facilitates the selection of services that evolve properly. Patterns specify best practices that emerge from multiple real‐world cases. In our context, the athletic heart syndrome comes out from a study that concerns the evolution of a set of popular, long‐lived Amazon services that cover different domains. According to the athletic heart syndrome, the developers should select services whose heartbeat of changes looks like the heartbeat of an athlete when he is at rest. Specifically, the heartbeat of changes should consist mostly of calm periods, interrupted by few spikes of change. Similarly, the incremental growth of the services should involve mainly calm periods of maintenance, separated by spikes of growth. Selecting services that adhere to the pattern signifies high chances that the services evolve to deal with changing requirements. The pattern further guarantees that the service evolution involves both the expansion of the services with new functionalities and the maintenance of existing ones. The pattern also assures that the complexity increase in the service interfaces will be smooth and tolerable. Finally, conformance with the pattern implies that the growth of the services will be predictable. [ABSTRACT FROM AUTHOR]

Pneumatosis intestinalis (PI) is a rare complication after thoracic organ transplantation. There are several theories for explaining the pathophysiology of this disease. In this paper, we highlight three cases of PI in a single pediatric center, one after lung transplantation and two after heart transplantation. Although the presentations differed, all cases improved with non‐surgical therapies. There are not many articles in the pediatric literature about post‐transplantation PI, and there are still many questions regarding the incidence, etiology, and treatment for this disease. [ABSTRACT FROM AUTHOR]

Aims: Aging is a critical contributing factor for cardiovascular diseases. The d‐galactose‐induced accelerated aging model is comparable to physiological aging from the cellular to the physiological level. The d‐galactose treatment induces mitochondrial dysfunction, increased reactive oxygen species (ROS) production, and upregulation of senescence‐related genes. Cordycepin, a functional element in Chinese traditional medicine, has multiple beneficial effects as an antioxidant and ROS scavenger, and has been reported to be effective in a number of ischemia models. This paper aims to investigate the cardioprotective effects of cordycepin in the d‐galactose accelerated aging model. Methods: In the current study, we employed the d‐galactose accelerated aging model to study the cardioprotective effect of cordycepin. Eight‐week‐old Sprague–Dawley rats, randomly divided into five groups, were given vehicle, d‐galactose (150 mg/kg/day), and cordycepin at 5, 10, and 20 mg/kg per day. At the end of the 8‐week treatment, rat cardiac structure and function were assessed with echocardiographic imaging and hemodynamic parameter analysis. Results: Cordycepin upregulated the expression of Klotho in serum and heart tissues. The expressions of senescence markers β‐galactosidase, p21, and oxidative stress marker malondialdehyde (MDA) were downregulated by cordycepin treatment. Reduction of levels and activity of the antioxidant factors superoxide dismutase (SOD) and catalase (CAT) induced by by d‐galactose treatment was ameliorated by cordycepin. Furthermore, cordycepin activated AMPK signaling in d‐galactose‐treated rats. After 8 weeks of treatment, we found that cordycepin improved myocardia contractility and hypertension caused by d‐galactose treatment. Mechanistically, reduced expression of the Klotho protein SOD1 caused by d‐galactose was recovered in rats co‐treated with cordycepin. Conclusion: Cordycepin could protect against cardiac dysfunction in a d‐galactose‐induced aging rat model, suggesting the therapeutic cardioprotective potential of cordycepin in aging. Geriatr Gerontol Int 2022; 22: 433–440. [ABSTRACT FROM AUTHOR]

Stem cells play key roles in development, tissue homeostasis, regeneration, ageing and diseases. Comprehensive reviews on stem cells are available for the determinately growing mammals and insects and some lower invertebrates like hydra but are rare for larger, indeterminately growing invertebrates that can live for many decades. This paper reviews the cytology, function and dynamics of stem and progenitor cells in the decapod crustaceans, a species‐rich and ecologically and economically important animal group that includes mainly indeterminate growers but also some determinate growers. Further advantages of decapods for stem cell research are almost 1000‐fold differences in body size and longevity, the regeneration of damaged appendages and the virtual absence of age‐related diseases and tumours in the indeterminately growing species. The available data demonstrate that the Decapoda possess a remarkable variety of structurally and functionally different stem cells in embryos and larvae, and in the epidermis, musculature, haematopoietic tissue, heart, brain, hepatopancreas, olfactory sense organs and gonads of adults. Some of these seem to be rather continuously active over a lifetime but others are cyclically activated and silenced in periods of days, weeks and years, depending on the specific organ and function. Stem cell proliferation is triggered by signals related to development, moulting, feeding, reproduction, injury, infection, environmental enrichment and social status. Some regulatory pathways have already been identified, including the evolutionarily conserved GATA‐binding and runt‐domain transcription factors, the widespread neurotransmitter serotonin, the arthropod‐specific hormone 20‐hydroxyecdysone and the novel astakine growth factors. Knowledge of stem cells in decapods primarily refines our picture on the development, growth and maintenance of tissues and organs in this animal group. Cultured decapod stem cells have good potential for toxicity testing and virus research with practical relevance for aquaculture. Knowledge of stem cells in decapods also broadens our understanding of the evolution of stem cells and regeneration in the animal kingdom. The stem cells of long‐lived, indeterminately growing decapods may hold the key to understanding how stem and progenitor cells function into old age without adverse side effects, possibly evoking new ideas for the development of anti‐ageing and anti‐cancer treatments in humans. [ABSTRACT FROM AUTHOR]

To extend the preservation of donor hearts beyond the current 4–6 h, this paper explores heart cryopreservation by vitrification—cryogenic storage in a glass‐like state. While organ vitrification is made possible by using cryoprotective agents (CPA) that inhibit ice during cooling, failure occurs during convective rewarming due to slow and non‐uniform rewarming which causes ice crystallization and/or cracking. Here an alternative, "nanowarming", which uses silica‐coated iron oxide nanoparticles (sIONPs) perfusion loaded through the vasculature is explored, that allows a radiofrequency coil to rewarm the organ quickly and uniformly to avoid convective failures. Nanowarming has been applied to cells and tissues, and a proof of principle study suggests it is possible in the heart, but proper physical and biological characterization especially in organs is still lacking. Here, using a rat heart model, controlled machine perfusion loading and unloading of CPA and sIONPs, cooling to a vitrified state, and fast and uniform nanowarming without crystallization or cracking is demonstrated. Further, nanowarmed hearts maintain histologic appearance and endothelial integrity superior to convective rewarming and indistinguishable from CPA load/unload control hearts while showing some promising organ‐level (electrical) functional activity. This work demonstrates physically successful heart vitrification and nanowarming and that biological outcomes can be expected to improve by reducing or eliminating CPA toxicity during loading and unloading. [ABSTRACT FROM AUTHOR]

The Production Assistance for Cellular Therapies (PACT) Program, is funded and supported by the US Department of Health and Human Services' National Institutes of Health (NIH) National Heart Lung and Blood Institute (NHLBI) to advance development of somatic cell and genetically modified cell therapeutics in the areas of heart, lung, and blood diseases. The program began in 2003, continued under two competitive renewals, and ended June 2021. PACT has supported cell therapy product manufacturing, investigational new drug enabling preclinical studies, and translational services, and has provided regulatory assistance for candidate cell therapy products that may aid in the repair and regeneration of damaged/diseased cells, tissues, and organs. PACT currently supports the development of novel cell therapies through five cell processing facilities. These facilities offer manufacturing processes, analytical development, technology transfer, process scale‐up, and preclinical development expertise necessary to produce cell therapy products that are compliant with Good Laboratory Practices, current Good Manufacturing Practices, and current Good Tissue Practices regulations. The Emmes Company, LLC, serves as the Coordinating Center and assists with the management and coordination of PACT and its application submission and review process. This paper discusses the impact and accomplishments of the PACT program on the cell therapy field and its evolution over the duration of the program. It highlights the work that has been accomplished and provides a foundation to build future programs with similar goals to advance cellular therapeutics in a coordinated and centralized programmatic manner to support unmet medical needs within NHLBI purview. [ABSTRACT FROM AUTHOR]

This paper presents a personal understanding of the work of two prominent writers, namely the English‐Polish author Joseph Conrad and the psychotherapist Robert Hobson. I make particular reference to Conrad's novel Heart of Darkness as a work that decidedly influenced the thinking of Hobson. The allegoric themes evoked provide a landscape of rich contemplation, heavily laden with metaphor and allowing an exploration of suicide and loss. With this, I have attempted to make a statement on the impact that suicide has upon the therapist and, in doing so, provide some clinical and personal vignettes relating to my experience with suicide. I also provide an account of a deeply traumatized patient with dissociative identity disorder and chronic suicidal ideation. These reflections draw upon the language of Conrad and Hobson as suicide is considered both in a concrete literal sense and as an expansive non‐linear metaphor. The term 'Conradian Horror' is given particular salience as evoking the dark and dismal vista of suicide and loss. [ABSTRACT FROM AUTHOR]

A relationship between COVID-19 infection and an increasing incidence of atrial fibrillation has been observed. However, the underlying pathophysiology as a precipitant to AF has not been reviewed. This paper will consider the possible pathological and immunological AF mechanisms as a result, of COVID-19 infection. We discuss the role myocardial microvascular pericytes expressing the ACE-2 receptor and their potential for an organ-specific cardiac involvement with COVID-19. Dysfunctional microvascular support by pericytes or endothelial cells may increase the propensity for AF via increased myocardial inflammation, fibrosis, increased tissue edema, and interstitial hydrostatic pressure. All of these factors can lead to electrical perturbances at the tissue and cellular level. We also consider the contribution of Angiotensin, pulmonary hypertension, and regulatory T cells as additional contributors to AF during COVID-19 infection. Finally, reference is given to two common drugs, corticosteroids and metformin, in COVID-19 and how they might influence AF incidence. [ABSTRACT FROM AUTHOR]

This paper begins with the understanding that early trauma leads to powerful dissociative defenses which injure the capacity to feel. It further explores ways to restore this capacity through body-centred attention to affect-in-the-moment in the psychoanalytic situation. Using the author's personal experience while in analysis as well as a case of severe early trauma, he demonstrates the consciousness-killing effect of primitive defenses and shows how body-sensitive techniques hold the promise of restoring the patient's sense of aliveness and hence, opening the unconscious to those affect-images that are the building blocks of the human imagination. A final section focuses on the neglect of feeling in Jungian psychology and suggests that the "creation of consciousness" which Jung described as his personal myth, is quintessentially a process of emotional transformation - of bringing unconscious suffering into consciousness - as feelings. [ABSTRACT FROM AUTHOR]

LINKED CONTENT: This article is linked to Wiese et al paper. To view this article, visit https://doi.org/10.1111/apt.17533 [ABSTRACT FROM AUTHOR]

The vast majority of acute heart failure episodes are characterized by increasing symptoms and signs of congestion with volume overload. The goal of therapy in those patients is the relief of congestion through achieving a state of euvolaemia, mainly through the use of diuretic therapy. The appropriate use of diuretics however remains challenging, especially when worsening renal function, diuretic resistance and electrolyte disturbances occur. This position paper focuses on the use of diuretics in heart failure with congestion. The manuscript addresses frequently encountered challenges, such as (i) evaluation of congestion and clinical euvolaemia, (ii) assessment of diuretic response/resistance in the treatment of acute heart failure, (iii) an approach towards stepped pharmacologic diuretic strategies, based upon diuretic response, and (iv) management of common electrolyte disturbances. Recommendations are made in line with available guidelines, evidence and expert opinion. [ABSTRACT FROM AUTHOR]

This article explores the significance of the image of the Chinese character for 'enlightenment'. The oracle bone script form for 'enlightenment' is comprised of the symbol for the 'true self' and the symbol for the 'heart'. In Chinese Taoist philosophy, the true self is close to Tao, a concept akin to that of the self in Analytical Psychology. The combination of the 'self' meeting with the 'heart' conveys both the aspect of inspiration and of profound meaning. The paper is composed of three parts in order to facilitate the analysis and interpretation of this Chinese character: 1) an exploration of the image and meaning of the character; 2) an exploration of the link between the self and enlightenment; and 3) reflections on the relationship between insight and enlightenment. The image of this Chinese character contains not only what enlightenment is, but also the way to enlightenment and the meaning of the way. [ABSTRACT FROM AUTHOR]

The final original article from B Cookson b and colleagues ( I Mansell i et al.) brings us back to the heart and imaging but draws on the bioengineering background of some of this issue's other papers by highlighting how MRI-based strain measurements can reflect morphological changes following myocardial infarction. Aorta, cardiovascular, disease, imaging, medical device, valve, ventricle Keywords: aorta; cardiovascular; disease; imaging; medical device; valve; ventricle EN aorta cardiovascular disease imaging medical device valve ventricle 1 2 2 12/26/22 20230101 NES 230101 Anatomy has evolved, over several hundreds of years, into a complex discipline spanning from the nanoscale to the macroscopic. [Extracted from the article]

ABSTRACT: The outflow tract of the fish heart is the segment interposed between the ventricle and the ventral aorta. It holds the valves that prevent blood backflow from the gill vasculature to the ventricle. The anatomical composition, histological structure and evolutionary changes in the fish cardiac outflow tract have been under discussion for nearly two centuries and are still subject to debate. This paper offers a brief historical review of the main conceptions about the cardiac outflow tract components of chondrichthyans (cartilaginous fish) and actinopterygians (ray‐finned fish) which have been put forward since the beginning of the nineteenth century up to the current day. We focus on the evolutionary origin of the outflow tract components and the changes to which they have been subject in the major extant groups of chondrichthyans and actinopterygians. In addition, an attempt is made to infer the primitive anatomical design of the heart of the gnathostomes (jawed vertebrates). Finally, several areas of further investigation are suggested. Recent work on fish heart morphology has shown that the cardiac outflow tract of chondrichthyans does not consist exclusively of the myocardial conus arteriosus as classically thought. A conus arteriosus and a bulbus arteriosus, devoid of myocardium and mainly composed of elastin and smooth muscle, are usually present in cartilaginous and ray‐finned fish. This is consistent with the suggestion that both components coexisted from the onset of the gnathostome radiation. There is evidence that the conus arteriosus appeared in the agnathans. By contrast, the evolutionary origin of the bulbus is still unclear. It is almost certain that in all fish, both the conus and bulbus develop from the embryonic second heart field. We suggest herein that the primitive anatomical heart of the jawed vertebrates consisted of a sinus venosus containing the pacemaker tissue, an atrium possessing trabeculated myocardium, an atrioventricular region with compact myocardium which supported the atrioventricular valves, a ventricle composed of mixed myocardium, and an outflow tract consisting of a conus arteriosus, with compact myocardium in its wall and valves at its luminal side, and a non‐myocardial bulbus arteriosus that connected the conus with the ventral aorta. Chondrichthyans have retained this basic anatomical design of the heart. In actinopterygians, the heart has been subject to notable changes during evolution. Among them, the following two should be highlighted: (i) a decrease in size of the conus in combination with a remarkable development of the bulbus, especially in teleosts; and (ii) loss of the myocardial compact layer of the ventricle in many teleost species. [ABSTRACT FROM AUTHOR]

Purpose: Identification and assessment of left ventricular (LV) global and regional wall motion (RWM) abnormalities are essential for clinical evaluation of various cardiovascular diseases. Currently, this evaluation is performed visually which is highly dependent on the training and experience of echocardiographers and thus is prone to considerable interobserver and intraobserver variability. This paper presents a new automatic method, based on nonlinear dimensionality reduction (NLDR) for global wall motion evaluation and also detection and classification of RWM abnormalities of LV wall in a three-point scale as follows: (1) normokinesia, (2) hypokinesia, and (3) akinesia. Methods: Isometric feature mapping (Isomap) is one of the most popular NLDR algorithms. In this paper, a modified version of Isomap algorithm, where image to image distance metric is computed using nonrigid registration, is applied on two-dimensional (2D) echocardiography images of one cycle of heart. By this approach, nonlinear information in these images is embedded in a 2D manifold and each image is characterized by a point on the constructed manifold. This new representation visualizes the relationship between these images based on LV volume changes. Then, a new global and regional quantitative index from the resultant manifold is proposed for global wall motion estimation and also classification of RWM of LV wall in a three-point scale. Obtained results by our method are quantitatively evaluated to those obtained visually by two experienced echocardiographers as the reference (gold standard) on 10 healthy volunteers and 14 patients. Results: Linear regression analysis between the proposed global quantitative index and the global wall motion score index and also with LV ejection fraction obtained by reference experienced echocardiographers resulted in the correlation coefficients of 0.85 and 0.90, respectively. Comparison between the proposed automatic RWM scoring and the reference visual scoring resulted in an absolute agreement of 82% and a relative agreement of 97%. Conclusions: The proposed diagnostic method can be used as a useful tool as well as a reference visual assessment by experienced echocardiographers for global wall motion estimation and also classification of RWM abnormalities of LV wall in a three-point scale in clinical evaluations. [ABSTRACT FROM AUTHOR]

Purpose: One approach to preclinical single-photon emission computed tomography (SPECT) imaging that provides both high resolution and high sensitivity is based on imaging a mouse inside a collimating tube; many magnified pinhole projection images from a small target region, e.g., the heart, can be recorded simultaneously on multiple detectors with little multiplexing since each pinhole aperture's opening angle is restricted to view mostly the target organ. However, to obtain complete data for reconstruction, it may be necessary to scan the mouse through the target region of the tube. The authors are developing a different approach based on acquisition and reconstruction of both low-resolution and high-resolution projection data acquired sequentially through many pinholes embedded in two tungsten tube sections of different diameters, a "scout" section and a high-resolution section, placed end-to-end along the axis of a triple-head clinical SPECT scanner. This paper describes the design procedures used to determine the geometric parameters of two new collimator-tube sections, as well as one approach for joint reconstruction of data acquired from both sections. Methods: The high-resolution section was designed by projecting as many pinhole views of a simulated mouse heart as possible over each detector's camera, with no overlapping of heart projections and minimal overlapping between adjacent "hot" organ and cardiac projections. The authors then jointly optimized the geometric design of the scout section for a triple-detector camera system, as well as the number of maximum-likelihood expectation maximization (MLEM) iterations required to provide minimum mean-squared error of reconstructed voxel counts throughout a 7-cm axial range, with the constraints of fixed, 2.4-mm scout system resolution at the tube center for all apertures, limited multiplexing, and no detector motion. Simulated mouse projection data from both tube sections were then reconstructed to illustrate a simple approach for using high-resolution data to improve the whole-body scout images within a cylindrical region surrounding the heart. Results: The 2-cm-inner-radius high-resolution tube section accommodated 87 platinum-iridium pinhole inserts, each with a 0.3-mm square aperture; their radial distances from the centerline of the system ranged from 2.2 to 3.0 cm. The optimal radial distance to the closest scout pinhole and optimal number of MLEM iterations were 4.4 cm and 35 iterations, respectively, and the radial distances of the 39 scout pinholes ranged from 4.4 to 4.8 cm; aperture sizes ranged from 1.1 to 1.7 mm transaxially and 0.9-1.5mmaxially. After including data from the high-resolution section viewing the heart region into whole-body mouse reconstructions from scout data, the authors obtained high-resolution images of the heart, embedded within lower resolution images of the body, with minimal artifacts. Conclusions: The authors have optimized a dual-resolution collimator tube that provides both whole-body projections of a mouse and more targeted projections centered on the heart that can be jointly reconstructed to obtain high-resolution images of the heart embedded within lower-resolution whole-body images. [ABSTRACT FROM AUTHOR]

Purpose: Accurate measurement of the right ventricle (RV) volume is important for the assessment of the ventricular function and a biomarker of the progression of any cardiovascular disease. However, the high RV variability makes difficult a proper delineation of the myocardium wall. This paper introduces a new automatic method for segmenting the RV volume from short axis cardiac magnetic resonance (MR) images by a salient analysis of temporal and spatial observations. Methods: The RV volume estimation starts by localizing the heart as the region with the most coherent motion during the cardiac cycle. Afterward, the ventricular chambers are identified at the basal level using the isodata algorithm, the right ventricle extracted, and its centroid computed. A series of radial intensity profiles, traced from this centroid, is used to search a salient intensity pattern that models the inner-outer myocardium boundary. This process is iteratively applied toward the apex, using the segmentation of the previous slice as a regularizer. The consecutive 2D segmentations are added together to obtain the final RV endocardium volume that serves to estimate also the epicardium. Results: Experiments performed with a public dataset, provided by the RV segmentation challenge in cardiac MRI, demonstrated that this method is highly competitive with respect to the state of the art, obtaining a Dice score of 0.87, and a Hausdorff distance of 7.26 mm while a whole volume was segmented in about 3 s. Conclusions: The proposed method provides an useful delineation of the RV shape using only the spatial and temporal information of the cine MR images. This methodology may be used by the expert to achieve cardiac indicators of the right ventricle function. [ABSTRACT FROM AUTHOR]

The following paper presents the findings of an exploratory ethnography, the purpose of which was to identify and describe heart health associated beliefs and behaviours of year seven (Y7) and year 10 (Y10) secondary school young people of African and African Caribbean descent in two UK cities. Data were collected by the data collection technique of focus groups. However, eight focus groups were conducted involving 47 Y7 young people and 29 Y10 pupils, 76 pupils in total. The data were analysed utilizing ATLAS/ti qualitative data analysis software. This software is informed by grounded theory. Data from the study formed six themes. The findings informed the development of an interactive health promotion website which can be found at http://www.shef.ac.uk/web/uni/projects/mshhp. The paper argues that in order to provide meaningful programmes of health promotion to be developed by health care providers including school nurses and health visitors, it is essential that interventions are informed by an understanding of the health beliefs and behaviours of African and African Caribbean young people. [ABSTRACT FROM AUTHOR]

In this paper, we propose an algorithm that optimizes the ventricular fiber structure of the human heart. A number of histological studies and diffusion tensor magnetic resonance imaging analyses have revealed that the myocardial fiber forms a right-handed helix at the endocardium. However, the fiber formation changes its orientation as a function of transmural depth, becoming a left-handed helix at the epicardium. To determine how nature can construct such a structure, which obtains surprising pumping performance, we introduce macroscopic modeling of the branching structure of cardiac myocytes in our finite element ventricular model and utilize this in an optimization process. We put a set of multidirectional fibers around a central fiber orientation at each point of the ventricle walls and simulate heartbeats by generating contraction forces along each of these directions. We examine two optimization processes using the workloads or impulses measured in these directions to update the central fiber orientation. Both processes improve the pumping performance towards an optimal value within several tens of heartbeats, starting from an almost-flat fiber orientation. However, compared with the workload optimization, the impulse optimization produces better agreement with experimental studies on transmural changes of fiber helix angle, streamline patterns of characteristic helical structures, and temporal changes in strain. Furthermore, the impulse optimization is robust under geometrical changes of the heart and tends to homogenize various mechanical factors such as the stretch and stretch rate along the fiber orientation, the contraction force, and energy consumption. [ABSTRACT FROM AUTHOR]

Purpose: There are several disease conditions that lead to upper airway restrictive disorders. In the study of these conditions, it is important to take into account the dynamic nature of the upper airway. Currently, dynamic magnetic resonance imaging is the modality of choice for studying these diseases. Unfortunately, the contrast resolution obtainable in the images poses many challenges for an effective segmentation of the upper airway structures. No viable methods have been developed to date to solve this problem. In this paper, the authors demonstrate a practical solution by employing an iterative relative fuzzy connectedness delineation algorithm as a tool. Methods: 3D dynamic images were collected at ten equally spaced instances over the respiratory cycle (i.e., 4D) in 20 female subjects with obstructive sleep apnea syndrome. The proposed segmentation approach consists of the following steps. First, image background nonuniformities are corrected which is then followed by a process to correct for the nonstandardness of MR image intensities. Next, standardized image intensity statistics are gathered for the nasopharynx and oropharynx portions of the upper airway as well as the surrounding soft tissue structures including air outside the body region, hard palate, soft palate, tongue, and other soft structures around the airway including tonsils (left and right) and adenoid. The affinity functions needed for fuzzy connectedness computation are derived based on these tissue intensity statistics. In the next step, seeds for fuzzy connectedness computation are specified for the airway and the background tissue components. Seed specification is needed in only the 3D image corresponding to the first time instance of the 4D volume; from this information, the 3D volume corresponding to the first time point is segmented. Seeds are automatically generated for the next time point from the segmentation of the 3D volume corresponding to the previous time point, and the process continues and runs without human interaction and completes in 10 s for segmenting the airway structure in the whole 4D volume. Results: Qualitative evaluations performed to examine smoothness and continuity of motions of the entire upper airway as well as its transverse sections at critical anatomic locations indicate that the segmentations are consistent. Quantitative evaluations of the separate 200 3D volumes and the 20 4D volumes yielded true positive and false positive volume fractions around 95% and 0.1%, respectively, and mean boundary placement errors under 0.5 mm. The method is robust to variations in the subjective action of seed specification. Compared with a segmentation approach based on a registration technique to propagate segmentations, the proposed method is more efficient, accurate, and less prone to error propagation from one respiratory time point to the next. Conclusions: The proposed method is the first demonstration of a viable and practical approach for segmenting the upper airway structures in dynamic MR images. Compared to registration-based methods, it effectively reduces error propagation and consequently achieves not only more accurate segmentations but also more consistent motion representation in the segmentations. The method is practical, requiring minimal user interaction and computational time. [ABSTRACT FROM AUTHOR]

Purpose: Calcium scoring is widely used to assess the risk of coronary heart disease (CHD). Accurate coronary artery calcification detection in noncontrast CT image is a prerequisite step for coronary calcium scoring. Currently, calcified lesions in the coronary arteries are manually identified by radiologists in clinical practice. Thus, in this paper, a fully automatic calcium scoring method was developed to alleviate the work load of the radiologists or cardiologists. Methods: The challenge of automatic coronary calcification detection is to discriminate the calcification in the coronary arteries from the calcification in the other tissues. Since the anatomy of coronary arteries is difficult to be observed in the noncontrast CT images, the contrast CT image of the same patient is used to extract the regions of the aorta, heart, and coronary arteries. Then, a patient-specific region-of-interest (ROI) is generated in the noncontrast CT image according to the segmentation results in the contrast CT image. This patient-specific ROI focuses on the regions in the neighborhood of coronary arteries for calcification detection, which can eliminate the calcifications in the surrounding tissues. A support vector machine classifier is applied finally to refine the results by removing possible image noise. Furthermore, the calcified lesions in the noncontrast images belonging to the different main coronary arteries are identified automatically using the labeling results of the extracted coronary arteries. Results: Forty datasets from four different CT machine vendors were used to evaluate their algorithm, which were provided by the MICCAI 2014 Coronary Calcium Scoring (orCaScore) Challenge. The sensitivity and positive predictive value for the volume of detected calcifications are 0.989 and 0.948. Only one patient out of 40 patients had been assigned to the wrong risk category defined according to Agatston scores (0, 1-100, 101-300, >300) by comparing with the ground truth. Conclusions: The calcified lesions in the noncontrast CT images can be detected automatically by using the segmentation results of the aorta, heart, and coronary arteries obtained in the contrast CT images with a very high accuracy. [ABSTRACT FROM AUTHOR]

Purpose: This paper represents the initial phase of a proposed operator-friendly semiautomatic method for positioning and directing an intravascular three-magnet tip catheter in the human heart using an electromagnetic system. Methods: A predictive computer algorithm based on a comprehensive mathematical model is developed, which accurately calculates the magnetic field generated by the electromagnet system as well as the magnetic torques and forces exerted on a three-magnet tip catheter, and generates the necessary electromagnet currents for arbitrary displacement and deflection of the catheter tip within a workspace of 128?128?128 mm. Results: We demonstrate the ability of the developed mathematical model to accurately position a three-magnet tip catheter within the 128?128?128 mm workspace of a 3D eight-electromagnet system. Conclusions: The ability of the developed mathematical model in predicting the displacement, direction, and deflection of the catheter tip as a function of the electromagnet current values has been verified through experimental results. [ABSTRACT FROM AUTHOR]

Purpose: Composition of the coronary artery plaque is known to have critical role in heart attack. While calcified plaque can easily be diagnosed by conventional CT, it fails to distinguish between fibrous and lipid rich plaques. In the present paper, the authors discuss the experimental techniques and obtain a numerical algorithm by which the electron density (pe) and the effective atomic number (Zeff) can be obtained from the dual energy computed tomography (DECT) data. The idea is to use this inversion method to characterize and distinguish between the lipid and fibrous coronary artery plaques. Methods: For the purpose of calibration of the CT machine, the authors prepare aqueous samples whose calculated values of (pe, Zeff) lie in the range of (2.65×1023 = pe = 3.64×1023/cm³) and (6.80 = Zeff = 8.90). The authors fill the phantom with these known samples and experimentally determine HU(V1) and HU(V2), with V1,V2 = 100 and 140 kVp, for the same pixels and thus determine the coefficients of inversion that allow us to determine (pe, Zeff) from the DECT data. The HU(100) and HU(140) for the coronary artery plaque are obtained by filling the channel of the coronary artery with a viscous solution of methyl cellulose in water, containing 2% contrast. These (pe, Zeff) values of the coronary artery plaque are used for their characterization on the basis of theoretical models of atomic compositions of the plaque materials. These results are compared with histopathological report. Results: The authors find that the calibration gives pe with an accuracy of ±3.5% while Zeff is found within ±1% of the actual value, the confidence being 95%. The HU(100) and HU(140) are found to be considerably different for the same plaque at the same position and there is a linear trend between these two HU values. It is noted that pure lipid type plaques are practically nonexistent, and microcalcification, as observed in histopathology, has to be taken into account to explain the nature of the observed (pe, Zeff) data. This also enables us to judge the composition of the plaque in terms of basic model which considers the plaque to be composed of fibres, lipids, and microcalcification. Conclusions: This simple and reliable method has the potential as an effective modality to investigate the composition of noncalcified coronary artery plaques and thus help in their characterization. In this inversion method, (pe, Zeff) of the scanned sample can be found by eliminating the effects of the CT machine and also by ensuring that the determination of the two unknowns (pe, Zeff) does not interfere with each other and the nature of the plaque can be identified in terms of a three component model. [ABSTRACT FROM AUTHOR]

Purpose: This work is a preliminary study of a stationary cardiac SPECT system. The goal of this research is to propose a stationary cardiac SPECT system using segmented slant-hole collimators and to perform computer simulations to test the feasibility. Compared to the rotational SPECT, a stationary system has a benefit of acquiring temporally consistent projections. The most challenging issue in building a stationary system is to provide sufficient projection view-angles. Methods: A GATE (GEANT4 application for tomographic emission) Monte Carlo model was developed to simulate a two-detector stationary cardiac SPECT that uses segmented slant-hole collimators. Each detector contains seven segmented slant-hole sections that slant to a common volume at the rotation center. Consequently, 14 view-angles over 180 were acquired without any gantry rotation. The NCAT phantom was used for data generation and a tailored maximum-likelihood expectation-maximization algorithm was used for image reconstruction. Effects of limited number of view-angles and data truncation were carefully evaluated in the paper. Results: Simulation results indicated that the proposed segmented slant-hole stationary cardiac SPECT system is able to acquire sufficient data for cardiac imaging without a loss of image quality, even when the uptakes in the liver and kidneys are high. Seven views are acquired simultaneously at each detector, leading to 5-fold sensitivity gain over the conventional dual-head system at the same total acquisition time, which in turn increases the signal-to-noise ratio by 19%. The segmented slant-hole SPECT system also showed a good performance in lesion detection. In our prototype system, a short hole-length was used to reduce the dead zone between neighboring collimator segments. The measured sensitivity gain is about 17-fold over the conventional dual-head system. Conclusions: The GATE Monte Carlo simulations confirm the feasibility of the proposed stationary cardiac SPECT system with segmented slant-hole collimators. The proposed collimator consists of combined parallel and slant holes, and the image on the detector is not reduced in size. [ABSTRACT FROM AUTHOR]

Purpose: Cardiac x-ray CT imaging is still challenging due to heart motion, which cannot be ignored even with the current rotation speed of the equipment. In response, many algorithms have been developed to compensate remaining motion artifacts by estimating the motion using projection data or reconstructed images. In these algorithms, accurate motion estimation is critical to the compensated image quality. In addition, since the scan range is directly related to the radiation dose, it is preferable to minimize the scan range in motion estimation. In this paper, the authors propose a novel motion estimation and compensation algorithm using a sinogram with a rotation angle of less than 360°. The algorithm estimates the motion of the whole heart area using two opposite 3D partial angle reconstructed (PAR) images and compensates the motion in the reconstruction process. Methods:A CT system scans the thoracic area including the heart over an angular range of 180° + α + β, where α and β denote the detector fan angle and an additional partial angle, respectively. The obtained cone-beam projection data are converted into cone-parallel geometry via row-wise fan-to-parallel rebinning. Two conjugate 3D PAR images, whose center projection angles are separated by 180°, are then reconstructed with an angular range of β, which is considerably smaller than a short scan range of 180° + α. Although these images include limited view angle artifacts that disturb accurate motion estimation, they have considerably better temporal resolution than a short scan image. Hence, after preprocessing these artifacts, the authors estimate a motion model during a half rotation for a whole field of view via nonrigid registration between the images. Finally, motion-compensated image reconstruction is performed at a target phase by incorporating the estimated motion model. The target phase is selected as that corresponding to a view angle that is orthogonal to the center view angles of two conjugate PAR images. To evaluate the proposed algorithm, digital XCAT and physical dynamic cardiac phantom datasets are used. The XCAT phantom datasets were generated with heart rates of 70 and 100 bpm, respectively, by assuming a system rotation time of 300 ms. A physical dynamic cardiac phantom was scanned using a slowly rotating XCT system so that the effective heart rate will be 70 bpm for a system rotation speed of 300 ms Results: In the XCAT phantom experiment, motion-compensated 3D images obtained from the proposed algorithm show coronary arteries with fewer motion artifacts for all phases. Moreover, object boundaries contaminated by motion are well restored. Even though object positions and boundary shapes are still somewhat different from the ground truth in some cases, the authors see that visibilities of coronary arteries are improved noticeably and motion artifacts are reduced considerably. The physical phantom study also shows that the visual quality of motion-compensated images is greatly improved. Conclusions: The authors propose a novel PAR image-based cardiac motion estimation and compensation algorithm. The algorithm requires an angular scan range of less than 360°. The excellent performance of the proposed algorithm is illustrated by using digital XCAT and physical dynamic cardiac phantom datasets. [ABSTRACT FROM AUTHOR]

Purpose: Effective and accurate segmentation of the aortic valve (AV) from sequenced ultrasound (US) images remains a technical challenge because of intrinsic factors of ultrasound images that impact the quality and the continuous changes of shape and position of segmented objects. In this paper, a novel shape-constraint gradient Chan-Vese (GCV) model is proposed for segmenting the AV from time serial echocardiography. Methods: The GCV model is derived by incorporating the energy of the gradient vector flow into a CV model framework, where the gradient vector energy term is introduced by calculating the deviation angle between the inward normal force of the evolution contour and the gradient vector force. The flow force enlarges the capture range and enhances the blurred boundaries of objects. This is achieved by adding a circle-like contour (constructed using the AV structure region as a constraint shape) as an energy item to the GCV model through the shape comparison function. This shapeconstrained energy can enhance the image constraint force by effectively connecting separate gaps of the object edge as well as driving the evolution contour to quickly approach the ideal object. Because of the slight movement of the AV in adjacent frames, the initial constraint shape is defined by users, with the other constraint shapes being derived from the segmentation results of adjacent sequence frames after morphological filtering. The AV is segmented from the US images by minimizing the proposed energy function. Results: To evaluate the performance of the proposed method, five assessment parameters were used to compare it with manual delineations performed by radiologists (gold standards). Three hundred and fifteen images acquired from nine groups were analyzed in the experiment. The area-metric overlap error rate was 6.89% ± 2.88%, the relative area difference rate 3.94% ± 2.63%, the average symmetric contour distance 1.08 ± 0.43 mm, the root mean square symmetric contour distance 1.37 ± 0.52 mm, and the maximum symmetric contour distance was 3.57 ± 1.72 mm. Conclusions: Compared with the CV model, as a result of the combination of the gradient vector and neighborhood shape information, this semiautomatic segmentation method significantly improves the accuracy and robustness of AV segmentation, making it feasible for improved segmentation of aortic valves from US images that have fuzzy boundaries. [ABSTRACT FROM AUTHOR]

Purpose: Reconstruction of the beating heart in 3D + time in the catheter laboratory using only the available C-arm system would improve diagnosis, guidance, device sizing, and outcome control for intracardiac interventions, e.g., electrophysiology, valvular disease treatment, structural or congenital heart disease. To obtain such a reconstruction, the patientˈs electrocardiogram (ECG) must be recorded during the acquisition and used in the reconstruction. In this paper, the authors present a 4D reconstruction method aiming to reconstruct the heart from a single sweep 10 s acquisition. Methods: The authors introduce the 4D RecOnstructiOn using Spatial and TEmporal Regularization (short 4D ROOSTER) method, which reconstructs all cardiac phases at once, as a 3D + time volume. The algorithm alternates between a reconstruction step based on conjugate gradient and four regularization steps: enforcing positivity, averaging along time outside a motion mask that contains the heart and vessels, 3D spatial total variation minimization, and 1D temporal total variation minimization. Results: 4D ROOSTER recovers the different temporal representations of a moving Shepp and Logan phantom, and outperforms both ECG-gated simultaneous algebraic reconstruction technique and prior image constrained compressed sensing on a clinical case. It generates 3D + time reconstructions with sharp edges which can be used, for example, to estimate the patientˈs left ventricular ejection fraction. Conclusions: 4D ROOSTER can be applied for human cardiac C-arm CT, and potentially in other dynamic tomography areas. It can easily be adapted to other problems as regularization is decoupled from projection and back projection. [ABSTRACT FROM AUTHOR]

The author reflects on L. W. Lo and colleagues' paper that reports the results of patients, who underwent mapping and ablation techniques for atrial fibrillation (AF) and recurrence of AF. An overview of several papers that highlight the perplexities of catheter ablation for AF is offered. The author also comments on the underlying mechanisms of therapeutic ablation for AF.

Purpose: To improve the accuracy and the robustness of the segmentation in living donor liver transplantation (LDLT) surgery planning system, the authors present a new segmentation framework that addresses challenges induced by the complex shape variations of patients' livers with cancer. It is designed to achieve the accurate and robust segmentation of hepatic parenchyma, portal veins, hepatic veins, and tumors in the LDLT surgery planning system. Methods: The segmentation framework proposed in this paper includes two important modules: (1) The robust shape prior modeling for liver, in which the sparse shape composition (SSC) model is employed to deal with the complex variations of liver shapes and obtain patient-specific liver shape priors. (2) The integration of the liver shape prior with a minimally supervised segmentation algorithm to achieve the accurate segmentation of hepatic parenchyma, portal veins, hepatic veins, and tumors simultaneously. The authors apply this segmentation framework to our previously developed LDLT surgery planning system to enhance its accuracy and robustness when dealing with complex cases of patients with liver cancer. Results: Compared with the principal component analysis, the SSC model shows a great advantage in handling the complex variations of liver shapes. It also effectively excludes gross errors and outliers that appear in the input shape and preserves local details for specific patients. The proposed segmentation framework was evaluated on the clinical image data of liver cancer patients, and the average symmetric surface distance for hepatic parenchyma, portal veins, hepatic veins, and tumors was 1.07 ± 0.76, 1.09 ± 0.28, 0.92 ± 0.35 and 1.13 ± 0.37 mm, respectively. The Hausdorff distance for these four tissues was 7.68, 4.67, 4.09, and 5.36 mm, respectively. Conclusions: The proposed segmentation framework improves the robustness of the LDLT surgery planning system remarkably when dealing with complex clinical liver shapes. The SSC model is able to handle non-Gaussian errors and preserve local detail information of the input liver shape. As a result, the proposed framework effectively addresses the problems caused by the complex shape variations of livers with cancer. Our framework not only obtains accurate segmentation results for healthy persons and common patients, but also shows high robustness when dealing with specific patients with large variations of liver shapes in complex clinical environments. [ABSTRACT FROM AUTHOR]

Thymosin β4 (Tβ4) is a peptide known for its abilities to protect and facilitate regeneration in a number of tissues following injury. Its cardioprotective effects have been evaluated in different animal models and, currently, a clinical trial is being planned in patients suffering from acute myocardial infarction. This paper focuses on the effects of Tβ4 on cardiac function in animal studies utilizing different imaging modalities for outcome measurements. [ABSTRACT FROM AUTHOR]

Heart and skeletal muscle inflammation (HSMI) is a disease causing considerable mortality in farmed Atlantic salmon. We have previously reported that pre-feeding of tetradecylthioacetic acid (TTA) reduces the mortality during a natural outbreak of HSMI. In the present paper we show that in the cardiac ventricle, during HSMI infection, pre-feeding TTA increases the expression of the immune genes: TNFα, VCAM-1, IgM and CD8α. We also show that TTA increases the cardiosomatic index potentially by elevating cardiomyogenesis through activation of the cardiac transcription factors MEF2C and Nkx2.5. Using the recently published genomic sequence of a HSMI associated piscine reovirus (PRV), we could show that the PRV levels have no confounding effects on the mRNA expression of the investigated genes. The results suggest that TTA induced cardiac growth, together with an elevated cardiac recruitment of immune cells, which might lead to increased robustness during HSMI infection. [ABSTRACT FROM AUTHOR]

Claudin proteins are the major components of tight junctions connecting adjacent cells, where they regulate a variety of cellular activities. In the present paper we identified two Xenopus claudin5 genes ( cldn5a and 5b), which are expressed early in the developing cardiac region. Precocious cldn5 expression was observed in explants of non-heart-forming mesoderm under inhibition of the canonical Wnt pathway. Cardiogenesis was severely perturbed by antisense oligonucleotides against cldn5 or by Cldn5 proteins lacking the cytoplasmic domain. Results of light- and electron-microscopic observations suggested that cldn5a and 5b are required for Xenopus heart tube formation through epithelialization of the precardiac mesoderm. [ABSTRACT FROM AUTHOR]

During early development, the initially straight heart tube (HT) bends and twists (loops) into a curved tube to lay out the basic plan of the mature heart. The physical mechanisms that drive and regulate looping are not yet completely understood. This paper reviews our recent studies of the mechanics of cardiac torsion during the first phase of looping (c-looping). Experiments and computational modeling show that torsion is primarily caused by forces exerted on the HT by the primitive atria and the splanchnopleure, a membrane that presses against the ventral surface of the heart. Experimental and numerical results are described and integrated to propose a hypothesis for cardiac torsion, and key aspects of our hypothesis are tested using experiments that perturb normal looping. For each perturbation, the models predict the correct qualitative response. These studies provide new insight into the mechanisms that drive and regulate cardiac looping. [ABSTRACT FROM AUTHOR]

This paper reports on the structure and ultrastructure of the ventricular myocardium of the African lungfish Protopterus dolloi in freshwater (FW), in aestivation (AE), and after the AE period. The myocardium shows a conventional myofibrillar structure. All the myocytes contain large intracytoplasmic spaces occupied by a pale material that could contain glycosaminoglycans and/or glycogen, which may be used as food and water reservoirs. In FW, the myocytes in the trabeculae associated with the free ventricular wall show structural signs of low transcriptional and metabolic activity (heterochromatin, mitochondria of the dense type). These signs are partially reversed during the AE period (euchromatin, mitochondria with a light matrix), with a return to the FW appearance after arousal. The myocytes in the septum show, in FW conditions, nuclear polymorphism (heterochromatin, euchromatin), and two types (colliquative and coagulative) of necrosis. In AE, all the septal myocytes show euchromatin, and the number of necrotic cells increases greatly. Cell necrosis appears to be related to the septal architecture. After arousal, the septal myocytes exhibit a heterochromatin pattern, the number of necrotic cells decreases, cell debris accumulates under the endocardium, and phagocytosis takes place. Despite being a morphologic continuum, the trabeculae associated with the free ventricular wall appear to constitute a different compartment from that formed by the trabeculae in the ventricular septum. Paradoxically, AE appears to trigger an increase in transcriptional and synthetic myocardial activities, especially at the level of the ventricular septum. This activity may be involved in mechanisms of autocrine/paracrine regulation. Aestivation cannot be regarded as the result of a general depression of all cellular and organic activities. Rather, it is a much more complex state in which the interplay between upregulation and downregulation of diverse cell activities appears to play a fundamental role. [ABSTRACT FROM AUTHOR]

Using a random speckle pattern as a quantitative transducer for displacement and deformation measurement constitutes a major milestone in the advancement of experimental mechanics techniques. Heretofore, displacement or strain transducers or gauges utilise regular patterns as the measurement base. It is the dimensional changes of these bases that are converted into displacement/strain information. The speckle method, on the other hand, uses a random array of particles (either physical or virtual) as displacement transducers. The displacement information of a cluster of random particles is obtained either through an optical processing scheme or a numerical algorithm. In this paper the development of the micro-/nano-speckle method with various applications is discussed. [ABSTRACT FROM AUTHOR]

Arteriosclerosis of the coronary artery has been described as a ‘fact of life’ for Pacific and Atlantic salmonids due to the high prevalence in spawning fish. The lesions are believed to be the result of overstretching of the highly distensible bulbus arteriosus whereby the endothelium of the main coronary vessel becomes mechanically damaged and a smooth muscle proliferation ensues with resultant partial occlusion of the vessel. The physiological significance for the function of the heart has yet to be demonstrated, but experimental studies show that, for example, swimming performance is compromised in fish in which the coronary artery has been ligated. This paper describes a case of myocardial necrosis in harvest-size Atlantic salmon during and after transportation to the slaughterhouse. Mortality during this process reached 10% in some of the transports and affected fish showed characteristic signs of congestive cardiac failure. Histology revealed extensive myointimal proliferation in the coronary artery and patchy necrosis of the compact ventricular myocardium. Several unfavourable factors such as high water temperature, skeletal malformations and crowding all probably contributed to extra cardiac workload. To the best of our knowledge, this is the first reported field case showing a link between coronary lesions and severe cardiac pathology. [ABSTRACT FROM AUTHOR]

Introduction: The aim of this paper was to review the outcomes of cardiac transplantation with regards to short- and long-term survival, focusing particularly on patients who receive organs with long ischemic times and the resource utilization necessary to support such patients through their postoperative period. Methods: A retrospective review of 420 consecutive cardiac transplants in a single institution was undertaken. Results: The five- and 10-yr survival rates for the entire group were 0.76 (95% CI: 0.72–0.80) and 0.60 (0.54–0.66). There was no decrease in mid- or long-term survival in patients who received organs with ischemic times over 300 min. Longer donor organ ischemic time was not associated with increased 30 d mortality but was significantly associated with longer intensive care bed stay, increased incidence of primary graft failure, need for mechanical support, and complications such as acute renal failures. Conclusions: Although using donor organs with longer ischemic times for cardiac transplantation does not impact on survival, there is a significantly increased utilization of resources to ensure these patients survive the postoperative period. [ABSTRACT FROM AUTHOR]

1. The purpose of the present paper is to discuss the long-term regulation of arterial blood pressure. Current thinking on the topic favours the theory that tight regulation is achieved through the action of a central (or primary) controller, usually assumed to be in either the brain or kidneys.2. Here, an alternative explanation is considered; namely, that the average long-term level of arterial pressure is an emergent property of a decentralized control system. The goal of the system is to deliver nutrient-rich blood to distinct vascular regions based on their energy demand.3. Specifically, the circulation is conceptualized as a free-market economy where tissues‘compete’ for a scarce resource (the energy contained in blood) supplied by the heart–lung unit; the‘price’ of the resource (analogous to the reciprocal of arterial pressure) is determined primarily by the dynamic relationship between supply and demand, not by a central mechanism.4. Based on this concept of the circulation as an energy market, economic analogies are used to suggest novel mechanisms by which the brain and kidney may affect the long-term control of blood pressure.5. Market-based control, a process derived from quantitative theoretical analysis of the performance of economic markets, is proposed as a new, potentially useful strategy for mathematically modelling the behaviour of the circulation. [ABSTRACT FROM AUTHOR]

Wray J, Radley-Smith R. Beyond the first year after pediatric heart or heart-lung transplantation: Changes in cognitive function and behaviour.Pediatr Transplantation 2005: 9: 170–177.© 2005 Blackwell MunksgaardWith the increasing use and improved survival rates of heart and lung transplantation as treatments for children with end-stage heart or lung disease, attention is focusing on the longer term psychological implications of these procedures. This paper focuses on the changes in cognitive development and behaviour in a group of 47 children who were seen 12 months and 2 yr after transplantation. There were 24 boys and 23 girls, mean age at transplantation was 8.3 yr (s.d. 5.3 yr), with a range of 0.3–15.1 yr. Assessments were made of developmental level, cognitive ability and problem behaviours, using previously validated measures, and comparisons were made with physically healthy children. For children under three and a half years of age there was a decrease over time in scores on all developmental parameters, with the change reaching significance on the scale assessing eye–hand coordination and on the overall IQ. Whilst all scores were within the normal range, they were at a significantly lower level than those of the healthy children. In contrast, there were no changes over time on any measures of cognitive or academic ability for older children, with correlations between 12 month and 2 yr scores being highly significant. The rate of behaviour problems at home at 12 months was 22%, compared with 34% at 2 yr post-transplant, which was higher than that found in the healthy children. Conversely, there was a drop in the prevalence of behaviour problems at school from 23% at 12 months to 9% at 2 yr. It is concluded that a significant minority of children and adolescents experience psychological difficulties 2 yr after transplant, with particular areas of concern focusing on development in the younger children and the occurrence of behaviour problems at home across the age-range. [ABSTRACT FROM AUTHOR]

Fabry disease is a rare X-linked disorder caused by deficient activity of the lysosomal enzymeα-galactosidase A. Progressive accumulation of the substrate globotriaosylceramide in cells throughout the body leads to major organ failure and premature death. The Fabry Outcome Survey (FOS) is a European outcomes database which was established to collect data on the natural history of this little-known disease and to monitor the long-term efficacy and safety of enzyme replacement therapy (ERT) with agalsidase alfa. This paper presents the first analysis of the FOS database on the effects of ERT on renal function, heart size, pain and quality of life.The effects of 1 and 2 years of ERT with agalsidase alfa on renal function (assessed by estimated glomerular filtration rate), heart size (assessed by echocardiography), pain (assessed by the Brief Pain Inventory) and quality of life (assessed by the European Quality of Life Questionnaire EQ-5D) were analyzed in a cohort of 545 patients, 314 of whom were receiving treatment (188 for at least 12 months and 92 for at least 24 months; mean duration of treatment, 17 months; maximum duration, 56 months).Treatment with agalsidase alfa stabilized renal function in patients with a mild or moderate deterioration in renal function at baseline, reduced left ventricular size in patients who had an enlarged heart at baseline, and improved pain scores and quality of life. These improvements were similar in hemizygous men and heterozygous women with Fabry disease.Enzyme replacement therapy with agalsidase alfa leads to significant clinical benefits in patients with Fabry disease, and treatment is likely to alter the natural history of this disorder.Eur J Clin Invest 2004; 34 (12): 838 –844 [ABSTRACT FROM AUTHOR]

Abstract Solid organ transplantation often leads to the return of fertility in recipients. In females of childbearing age this can be accompanied by a desire to have children. The present paper discusses a planned pregnancy in a heart transplant recipient and outlines important ­management issues. These principles of management can be applied to most solid organ transplant recipients. (Intern Med J 2004; 34: 206−209) [ABSTRACT FROM AUTHOR]

Abstract The conus (bulbo-ventricular) valves of teleosts perform a key function in the control of blood backflow during ventricular diastole. However, the structural characteristics of these valves are almost unknown. This paper presents a systematic anatomical, histological and structural study of the conus valves of the adult gilthead seabream (Sparus auratus ). S. auratus shows two major left and right valves consisting of the leaflet and the supporting sinus. Each valvar leaflet can be divided into a stout proximal body and a flap-like distal region. The proximal body is structured into three layers: a luminal fibrosa, a dense cellular core and a parietal fibrosa. The luminal fibrosa is a collagenous structure extending the entire length of the leaflet, while the parietal fibrosa is restricted to the most proximal area. The dense cellular core consists of fibroblastic cells and a matrix rich in glycoconjugates, collagen and elastin. The histochemical and structural data suggest that the luminal fibrosa bears most of the force associated with valvar closure, while the cellular core acts as a cushion dampening vibrations and absorbing the elastic recoil. The sinus wall is a fibrous layer which shows proximal–distal differences in thickness. It also shows compositional differences that can be related to mechanical function. We describe the presence of a fibrous cylinder formed by the sinus wall, the fibrous interleaflet triangles and the fibrous layer that covers the inner surface of the conus myocardium. This fibrous cylinder constitutes the structural nexus between the ventricle, the conus and the bulbus arteriosus, provides support for the conus valves and separates the valvar complex from the surrounding tissues. The structure of the conus valves in S. auratus is different from that found in other vertebrates. Anatomical similarities between the conus valves and the mammalian arterial valves are emphasized. Each phyletic group appears to have... [ABSTRACT FROM AUTHOR]

Unlabelled: This paper reports the first data of a study on heart rate variations of 13 5-mo-old infants seated in special chairs. Their electrocardiograms and behaviour were continuously recorded during sessions that were set up with their mother and a mother-child dyad that they met for the first time when the first session was organized. The protocol comprised two interaction phases between the infants and their mothers and two with one another. The same pairs of mother-child dyads were studied a second time 1 wk later. During the first session, the infants' heart rate variability increased significantly from the mother-infant interaction phases to the infant-infant interaction phases. During the second session, the variability was higher during the mother-infant phases than in the corresponding phases of the first session. This could be linked to changes in the mothers' behaviour and the infants' idea and excitement of meeting the child from the first session again. However, the variability was significantly lower during the infant-infant phases than during the mother-infant phases and the corresponding infant-infant phases of the first session. This corresponds to the development of affiliative behaviours in the infants.Conclusion: When two 5-mo-old infants were seated by their mothers in special chairs, significant differences were observed in their heart rate variability when they became familiar with each other, whether they were interacting with their mothers or with one another. [ABSTRACT FROM AUTHOR]

In recent years, magnetic resonance imaging (MRI) systems have been in demand to diagnose moving parts in the human body such as the heart or the blood in angiography, where images should be taken in milliseconds instead of minutes. Gradient power amplifiers, which are small but vital components for advanced MRI, require higher output power capacity as well as faster rise/fall dynamic response characteristics under a variety of specified current reference signals. This paper presents a novel switch-mode gradient power amplifier using IGBTs which are connected in parallel to a conventional four-switch full-bridge power conversion circuit at their inputs/outputs in order to realize a higher power density. To satisfy the design specifications, which require minimized ripple and improved rise/fall dynamic response characteristics of the current in the gradient coil, a unique digital control scheme based on an optimal type 1 servo system is proposed and described in detail. The effectiveness of the above is discussed and evaluated through computer-aided analysis. It is expected that the proposed techniques will greatly expand the diagnostic targets and improve the image quality of MRI. © 2000 Scripta Technica, Electr Eng Jpn, 132(1): 64–72, 2000 [ABSTRACT FROM AUTHOR]