Normal cardiac dimensions by magnetic resonance imaging and topographic anatomy of the adult arabian one-humped camel (Camelus dromedarius).

BACKGROUND: Dromedaries' normal heart architecture and size have not been adequately examined utilizing magnetic resonance imaging (MRI) and topographic anatomy. RESULT: we aimed to investigate the regular appearance of the heart and its dimensions, using MRI and cross-sectional anatomy, in mature Arabian one-humped camels (Camelus dromedarius). We also analyzed hematological and cardiac biochemical markers. MRI scans were conducted on twelve camel heart cadavers using a closed 1.5-Tesla magnet with fast spin echo (FSE) weighted sequences. Subsequently, the hearts were cross-sectionally sliced. Additionally, hematobiochemical studies were conducted on ten mature live camels. The study analyzed standard cardiac dimensions including HL, BW, RA, LA, RV, LV, IVS, LAD, RAD, RVD, AoD, TCVD, and MVD. The results showed a strong positive correlation between the cardiac dimensions obtained from both gross analysis and MR images, with no significant difference between them. On both gross and MRI images, the usual structures of the heart were identified and labeled. Along with the cardiac markers (creatine kinase and troponin), the average hematological values and standard biochemical parameters were also described. CONCLUSION: According to what we know, this investigation demonstrates, for the first time the typical heart structures and dimensions of the heart in dromedaries, and it could serve as a basis for diagnosing cardiac disorders in these animals.

Transthoracic echocardiography is a simple tool for size matching in cardiac xenotransplantation.

BACKGROUND: Preoperative size matching is essential for both allogeneic and xenogeneic heart transplantation. In preclinical pig-to-baboon xenotransplantation experiments, porcine donor organs are usually matched to recipients by using indirect parameters, such as age and total body weight. For clinical use of xenotransplantation, a more precise method of size measurement would be desirable to guarantee a "perfect match." Here, we investigated the use of transthoracic echocardiography (TTE) and described a new method to estimate organ size prior to xenotransplantation. METHODS: Hearts from n = 17 genetically modified piglets were analyzed by TTE and total heart weight (THW) was measured prior to xenotransplantation into baboons between March 2018 and April 2022. Left ventricular (LV) mass was calculated according to the previously published method by Devereux et al. and a newly adapted formula. Hearts from n = 5 sibling piglets served as controls for the determination of relative LV and right ventricular (RV) mass. After explantation, THW and LV and RV mass were measured. RESULTS: THW correlated significantly with donor age and total body weight. The strongest correlation was found between THW and LV mass calculated by TTE. Compared to necropsy data of the control piglets, the Devereux formula underestimated both absolute and relative LV mass, whereas the adapted formula yielded better results. Combining the adapted formula and the relative LV mass data, THW can be predicted with TTE. CONCLUSIONS: We demonstrate reliable LV mass estimation by TTE for size matching prior to xenotransplantation. An adapted formula provides more accurate results of LV mass estimation than the generally used Devereux formula in the xenotransplantation setting. TTE measurement of LV mass is superior for the prediction of porcine heart sizes compared to conventional parameters such as age and total body weight.

Genetic diversity, growth and heart function of Auckland Island pigs, a potential source for organ xenotransplantation.

One of the prerequisites for successful organ xenotransplantation is a reasonable size match between the porcine organ and the recipient's organ to be replaced. Therefore, the selection of a suitable genetic background of source pigs is important. In this study, we investigated body and organ growth, cardiac function, and genetic diversity of a colony of Auckland Island pigs established at the Center for Innovative Medical Models (CiMM), LMU Munich. Male and female Auckland Island pig kidney cells (selected to be free of porcine endogenous retrovirus C) were imported from New Zealand, and founder animals were established by somatic cell nuclear transfer (SCNT). Morphologically, Auckland Island pigs have smaller body stature compared to many domestic pig breeds, rendering their organ dimensions well-suited for human transplantation. Furthermore, echocardiography assessments of Auckland Island pig hearts indicated normal structure and functioning across various age groups throughout the study. Single nucleotide polymorphism (SNP) analysis revealed higher runs of homozygosity (ROH) in Auckland Island pigs compared to other domestic pig breeds and demonstrated that the entire locus coding the swine leukocyte antigens (SLAs) was homozygous. Based on these findings, Auckland Island pigs represent a promising genetic background for organ xenotransplantation.

Vertebral heart size and vertebral left atrial size reference ranges in healthy Miniature Schnauzers.

OBJECTIVE: The inclusion of vertebral heart score (VHS) and, more recently, the inclusion of the vertebral left atrial size (VLAS) in radiographic evaluation have become important screening tools for identifying dogs with occult cardiac disease. Several recent papers have shown there are interbreed variations in the VHS reference range. Our hypothesis is that the Miniature Schnauzer would also have a higher reference range for its VHS. ANIMALS: The electronic medical records of IDEXX Telemedicine Consultants were searched for Miniature Schnauzers undergoing thoracic radiographs between March 1, 2022, and February 28, 2023. METHODS: Dogs were included if they had 3 view thoracic radiographs performed and no evidence of cardiopulmonary disease was detected. Dogs with incomplete radiographic studies or cardiac or extracardiac disease were excluded. The VHS and VLAS measurements were performed by 2 board-certified cardiologists independent of one another. RESULTS: A total of 1,000 radiographs were obtained of which 272 were included for the study. The overall range for the VHS in this cohort was 9.68 to 12.07 with a median of 10.9. For VLAS measurements, a range of 1.71 to 2.4 was documented with a median of 2.0. CLINICAL RELEVANCE: The VHS for Miniature Schnauzers without cardiac disease was confirmed to be higher than the canine reference range.

The athlete's heart: allometric considerations on published papers and relation to cardiovascular variables.

To evaluate the morphology of the "athlete's heart", left ventricular (LV) wall thickness (WT) and end-diastolic internal diameter (LVIDd) at rest were addressed in publications on skiers, rowers, swimmers, cyclists, runners, weightlifters (n = 927), and untrained controls (n = 173) and related to the acute and maximal cardiovascular response to their respective disciplines. Dimensions of the heart at rest and functional variables established during the various sport disciplines were scaled to body weight for comparison among athletes independent of body mass. The two measures of LV were related (r = 0.8; P = 0.04) across athletic disciplines. With allometric scaling to body weight, LVIDd was similar between weightlifters and controls but 7%-15% larger in the other athletic groups, while WT was 9%-24% enlarged in all athletes. The LVIDd was related to stroke volume, oxygen pulse, maximal oxygen uptake, cardiac output, and blood volume (r = ~ 0.9, P < 0.05), while there was no relationship between WT and these variables (P > 0.05). In conclusion, while cardiac enlargement is, in part, essential for the generation of the cardiac output and thus stroke volume needed for competitive endurance exercise, an enlarged WT seems important for the development of the wall tension required for establishing normal arterial pressure in the enlarged LVIDd.

Spatially organized cellular communities form the developing human heart.

The heart, which is the first organ to develop, is highly dependent on its form to function1,2. However, how diverse cardiac cell types spatially coordinate to create the complex morphological structures that are crucial for heart function remains unclear. Here we integrated single-cell RNA-sequencing with high-resolution multiplexed error-robust fluorescence in situ hybridization to resolve the identity of the cardiac cell types that develop the human heart. This approach also provided a spatial mapping of individual cells that enables illumination of their organization into cellular communities that form distinct cardiac structures. We discovered that many of these cardiac cell types further specified into subpopulations exclusive to specific communities, which support their specialization according to the cellular ecosystem and anatomical region. In particular, ventricular cardiomyocyte subpopulations displayed an unexpected complex laminar organization across the ventricular wall and formed, with other cell subpopulations, several cellular communities. Interrogating cell-cell interactions within these communities using in vivo conditional genetic mouse models and in vitro human pluripotent stem cell systems revealed multicellular signalling pathways that orchestrate the spatial organization of cardiac cell subpopulations during ventricular wall morphogenesis. These detailed findings into the cellular social interactions and specialization of cardiac cell types constructing and remodelling the human heart offer new insights into structural heart diseases and the engineering of complex multicellular tissues for human heart repair.

Structure-aware independently trained multi-scale registration network for cardiac images.

Image registration is a primary task in various medical image analysis applications. However, cardiac image registration is difficult due to the large non-rigid deformation of the heart and the complex anatomical structure. This paper proposes a structure-aware independently trained multi-scale registration network (SIMReg) to address this challenge. Using image pairs of different resolutions, independently train each registration network to extract image features of large deformation image pairs at different resolutions. In the testing stage, the large deformation registration is decomposed into a multi-scale registration process, and the deformation fields of different resolutions are fused by a step-by-step deformation method, thus solving the difficulty of directly processing large deformation. Meanwhile, the targeted introduction of MIND (modality independent neighborhood descriptor) structural features to guide network training enhances the registration of cardiac structural contours and improves the registration effect of local details. Experiments were carried out on the open cardiac dataset ACDC (automated cardiac diagnosis challenge), and the average Dice value of the experimental results of the proposed method was 0.833. Comparative experiments showed that the proposed SIMReg could better solve the problem of heart image registration and achieve a better registration effect on cardiac images.

Morphological Assessment and Possible Clinical Implications of the Left Ventricle Papillary Muscles. Study in a Colombian Population Sample

SUMMARY: Papillary muscles in the left ventricle present multiple anatomic expressions that are relevant for medical fields focusing on the understanding of clinical events involving these structures. Here, the aim was to perform a morphological characterization of the left ventricle papillary muscles in a sample of Colombian population. In the study were included eighty-two hearts from male individuals who underwent autopsy at the Institute of Legal Medicine and Forensic Sciences in Bucaramanga, Colombia. In each heart was carefully performed a longitudinal incision on the obtuse margin to visualize the papillary muscles. Data set was registered, and analysis of the continuous and categorical variables was carried out. Single anterior papillary muscle was observed in 74 samples (90.2 %) whereas this represented only 48 specimens (58.5 %) for the posterior papillary muscle (p = 0.3). Mean length and breadth of the anterior muscle were 29.9 ± 4.94 and 11.74 ± 2.75 mm, and those for the posterior muscle were 27.42 ± 7.08 and 10.83 ± 4.08 mm. Truncated apical shape was the most frequent type observed on the papillary muscles, anterior 41 (50 %) and posterior 37 (45.1 %), followed by flat-topped in the anterior 25 (30.5 %) and bifurcated in posterior muscle 14 (17.1 %). A mean of 9.04 ± 2.75 chordae raised from the anterior and 7.50 ± 3.3 from posterior papillary muscle. In our study we observed a higher incidence of single papillary muscles and slightly larger dimensions than information reported in the literature. The anatomic diversity of the papillary muscles should be considered for the correct image interpretation, valve implantation and performance evaluation on myocardial ischemic events.

Los músculos papilares del ventrículo izquierdo presentan múltiples expresiones anatómicas que son relevantes para las áreas médicas que se centran en la comprensión de los eventos clínicos que involucran estas estructuras. El objetivo fue realizar una caracterización morfológica de los músculos papilares del ventrículo izquierdo en una muestra de población colombiana. En el estudio se incluyeron ochenta y dos corazones de individuos masculinos a los que se les realizó autopsia en el Instituto de Medicina Legal y Ciencias Forenses de Bucaramanga, Colombia. En cada corazón se realizó cuidadosamente una incisión longitudinal en el margen obtuso para visualizar los músculos papilares. Se registró el conjunto de datos y se realizó el análisis de las variables continuas y categóricas. Se observó un solo músculo papilar anterior en 74 muestras (90,2 %), mientras que este rasgo se presentó en 48 muestras (58,5 %) para el músculo papilar posterior (p = 0,3). La longitud y anchura media del músculo anterior fueron 29,9 ± 4,94 y 11,74 ± 2,75 mm, y las del músculo posterior fueron 27,42 ± 7,08 y 10,83 ± 4,08 mm. La forma apical truncada fue el tipo más frecuente observado en los músculos papilares, anterior 41 (50 %) y posterior 37 (45,1 %), seguido de la forma plana en los 25 anteriores (30,5 %) y bifurcada en el músculo posterior 14 (17,1 %). Una media de 9,04 ± 2,75 cuerdas elevadas desde el músculo papilar anterior y 7,50 ± 3,3 desde posterior. En nuestro estudio observamos una mayor incidencia de músculos papilares únicos y dimensiones ligeramente mayores que la información reportada en la literatura. La diversidad anatómica de los músculos papilares debe ser considerada para la correcta interpretación de imágenes, implantación valvular y evaluación del desempeño en eventos isquémicos miocárdicos.

Trabeculations of the porcine and human cardiac ventricles are different in number but similar in total volume.

An intricate meshwork of trabeculations lines the luminal side of cardiac ventricles. Compaction, a developmental process, is thought to reduce trabeculations by adding them to the neighboring compact wall which is then enlarged. When pig, a plausible cardiac donor for xenotransplantation, is compared to human, the ventricular walls appear to have fewer trabeculations. We hypothesized the trabecular volume is proportionally smaller in pig than in human. Macroscopically, we observed in 16 pig hearts that the ventricular walls harbor few but large trabeculations. Close inspection revealed a high number of tiny trabeculations, a few hundred, within the recesses of the large trabeculations. While tiny, these were still larger than embryonic trabeculations and even when considering their number, the total tally of trabeculations in pig was much fewer than in human. Volumetrics based on high-resolution MRI of additional six pig hearts compared to six human hearts, revealed the left ventricles were not significantly differently trabeculated (21.5 versus 22.8%, respectively), and the porcine right ventricles were only slightly less trabeculated (42.1 vs 49.3%, respectively). We then analyzed volumetrically 10 pig embryonic hearts from gestational day 14-35. The trabecular and compact layer always grew, as did the intertrabecular recesses, in contrast to what compaction predicts. The proportions of the trabecular and compact layers changed substantially, nonetheless, due to differences in their growth rate rather than compaction. In conclusion, processes that affect the trabecular morphology do not necessarily affect the proportion of trabecular-to-compact myocardium and they are then distinct from compaction.

Radiation therapy in the thoracic region: Radio-induced cardiovascular disease, cardiac delineation and sparing, cardiac dose constraints, and cardiac implantable electronic devices.

Radiation therapy in the thoracic region may deliver incidental ionizing radiation to the surrounding healthy structures, including the heart. Radio-induced heart toxicity has long been a concern in breast cancer and Hodgkin's lymphoma and was deemed a long-term event. However, recent data highlight the need to limit the dose to the heart in less favorable thoracic cancers too, such as lung and esophageal cancers in which incidental irradiation led to increased mortality. This article will summarize available cardiac dose constraints in various clinical settings and the types of radio-induced cardiovascular diseases encountered as well as delineation of cardiac subheadings and management of cardiac devices. Although still not completely deciphered, heart dose constraints remain intensively investigated and the mean dose to the heart is no longer the only dosimetric parameter to consider since the left anterior descending artery as well as the left ventricle should also be part of dosimetry constraints.

Conservation of Organs (Heart, Brain and Kidney) of Canine by Cold-Temperature Silicone Plastination in an Animal Anatomy Laboratory in Ecuador / Conservación de Órganos (Corazón, Encéfalo y Riñón) de Canino Mediante la Técnica de Plastinación en Silicona al Frío Realizada en Laboratorio de Anatomía Animal en Ecuador

SUMMARY: For the purposes of teaching anatomy, the use of cadaver preparations is considered the most efficient way of ensuring that students retain knowledge. Nevertheless, in Ecuador the use of animal specimens in universities must comply with the internationally accepted principles of replacement, reduction and refinement (3Rs). Plastination is an alternative technique which allows organs to be conserved in the long term and complies with the 3Rs. The object of the present work was to use cold-temperature silicone plastination with Biodur® products to obtain long-lasting, easy-to-handle canine organs for use as tools for the teaching of animal anatomy. Six canine cadavers were obtained from local animal protection charities. The hearts, brains and kidneys of the cadavers were dissected and fixed with formaldehyde 10 %. They were then dehydrated with acetone at -20 °C. The specimens were impregnated with Biodur® S10:S3 (-20 °C) and finally cured with Biodur® S6. We plastinated six hearts, twelve kidneys, four brains and one encephalic slice of canine. The application of cold-temperature plastination to canine organs followed the parameters established for the conventional protocol, enabling us to obtain organs of brilliant appearance, free of odours, in which the anatomical form was preserved. Thus the technique helped us to comply with the 3Rs, as we obtained easy-to-handle teaching models to replace fresh or formaldehyde-fixed samples for the teaching-learning of the canine anatomy.

En la enseñanza de la Anatomía, el uso de preparaciones cadavéricas se considera el método que permite a los estudiantes retener el conocimiento de una forma más eficiente. No obstante, en Ecuador, el uso de especímenes animales en las universidades se debe realizar bajo el principio internacional de reemplazo, reducción y refinamiento (3Rs). La técnica de plastinación es una técnica alternativa que permite preservar órganos a largo plazo y que se adapta al principio de las 3Rs. El objetivo del trabajo fue utilizar la técnica de plastinación en silicona al frío con productos Biodur® para obtener órganos caninos duraderos y manejables útiles como herramienta para la enseñanza de la anatomía animal. Se obtuvieron seis cadáveres de caninos de fundaciones locales para la protección animal. Se realizaron disecciones de corazones, cerebros y riñones de los cadáveres caninos. Los órganos se fijaron con formalina al 10 %. A continuación, se llevó a cabo la deshidratación con acetona a -20 °C. Los especímenes fueron impregnados con S10:S3 Biodur® (-20 °C) y al final fueron curados con Biodur® S6. Se lograron plastinar seis corazones, doce riñones, cinco encéfalos y un tallo encefálico de canino. La técnica de plastinación al frío utilizada para obtener órganos de canino conservó los parámetros empleados en el protocolo convencional y permitió obtener órganos que presentaron aspecto brillante, ausencia de olores y mantuvieron la forma anatómica. Por lo que, la técnica facilitó cumplir con el principio de las 3Rs al obtenerse modelos didácticos fáciles de manipular que pueden reemplazar muestras frescas o formolizadas en el proceso de enseñanza-aprendizaje de la anatomía del canino.

Cardiac Corpuscles: A "New" Morphofunctional Entity? / Corpúsculos Cardíacos: ¿Una "Nueva" Entidad Morfofuncional?

SUMMARY: The existence of "transitional muscular structures" between subendocardial branches (Purkinje fibers) and ventricular working muscle fibers (WF) was first described by the German anatomist, Kurt Goerttler, in 1964. He designated them as "subendocardial nucleus organs." He supposed such fibers functioned as mechanoreceptors, controlling of the intensity of contraction of the ventricular musculature. Brazilian anatomist Ferraz de Carvalho described similar structures in 1993. A thorough literature search failed to identify any other research articles confirming or denying their existence. The objective of this work was to find such structures in subendocardial ventricular walls in human hearts. We collected fifteen formalin-preserved hearts from the Anatomy Department of São Paulo University and sectioned the apical portions on the right and left ventricles according to method used by Goerttler. We utilized conventional histology (light microscopy- LM), scanning electron microscopy (SEM), and a new preservation method called micro- plastination (MP). At the anterior wall of the right ventricle in the subendocardial region between the interventricular septum and moderator band, we found several bundles of fusiform and helicoidal fibers of similar histology to the WF. The bundles measured between 400 and 1150 µm in length and were separated from adjacent muscular fibers by thin collagen fiber, thus acting as a "pseudo capsule." Some structures seemed to be linked to PF and were appeared to be lymphatic and blood vessels and nerves. We called those structures "cardiac corpuscles" (CC). The observation of the previously "unknown" CC in this initial study confirmed the previous descriptions and its discovery may contribute to new perspectives in the study of cardiac muscle structure and function.

La existencia de "estructuras musculares de transición" entre los ramos subendocárdicos (fibras de Purkinje) y las fibras musculares ventriculares activas(FMV) fue descrita por primera vez por el anatomista alemán Kurt Goerttler en 1964, quien las denominó "órganos del núcleo subendocárdico". Supuso que tales fibras funcionaban como mecanoreceptores, controlando la intensidad de la contracción de la musculatura ventricular. El anatomista brasileño Ferraz de Carvalho describió estructuras similares en 1993. Una búsqueda bibliográfica exhaustiva no logró identificar ningún otro artículo de investigación que confirmara o negara su existencia. El objetivo de este trabajo fue encontrar dichas estructuras en las paredes ventriculares subendocárdicas de corazones humanos. Recolectamos 15 corazones conservados en formalina del Departamento de Anatomía de la Universidad de São Paulo y seccionamos las porciones apicales de los ventrículos derecho e izquierdo según el método utilizado por Goerttler. Utilizamos histología convencional (microscopía de luz-LM), microscopía electrónica de barrido (SEM) y un nuevo método de conservación llamado microplastinación (MP). En la pared anterior del ventrículo derecho en la región subendocárdica entre el tabique interventricular y la banda moderadora, encontramos varios haces de fibras fusiformes y helicoidales de histología similar a la FMV. Los haces medían entre 400 y 1150 µm de longitud y estaban separados de las fibras musculares adyacentes por una fina fibra de colágeno, actuando así como una "pseudocápsula". Algunas estructuras parecían estar vinculadas a la fibras de purkinje y parecían ser vasos linfáticos, sanguíneos y nerviosos. Llamamos a esas estructuras "corpúsculos cardíacos" (CC). La observación del CC previamente "desconocido" en este estudio inicial confirmó las descripciones anteriores y su descubrimiento puede contribuir a nuevas perspectivas en el estudio de la estructura y función del músculo cardíaco.

Normal Ventricular and Regional Blood Flow Volumes and Native T1 Values in Healthy Japanese Children Obtained from Comprehensive Cardiovascular Magnetic Resonance Imaging.

Age-related mean and reference ranges for ventricular volumes and mass, regional blood flow measurements, and T1 values using cardiovascular magnetic resonance (CMR) imaging are yet to be established for the pediatric population. Especially in infants and toddlers, no consistent flow volume sets or T1 values have been reported. The purpose of this study was to determine the relevant normal values.Twenty-three children (aged 0.1-15.3 years) without cardiovascular diseases were included. Comprehensive CMR imaging including cine, 2-dimensional phase-contrast, and native T1 mapping, were performed. Ventricular volumes and masses, 11 sets of regional blood flow volumes, and myocardial and liver T1 values were measured. All intraclass correlation coefficient values were > 0.94, except for the right ventricular mass (0.744), myocardial (0.868) and liver T1 values (0.895), reflecting good to excellent agreement between rates.Regression analysis showed an exponential relationship between body surface area (BSA) and ventricular volumes, mass, and regional blood flow volumes (normal value = a*BSAb). Left ventricular myocardial T1 values were regressed on linear regression with age (normal value = -7.39*age + 1091), and hepatic T1 values were regressed on a quadratic function of age (normal value = 0.923*age2 -18.012*age + 613).Comparison of the 2 different methods for the same physical quantities by Bland-Altman plot showed no difference except that the right ventricular stroke volume was 1.5 mL larger than the main pulmonary trunk flow volume.This study provides the normal values for comprehensive CMR imaging in Japanese children.

Spatially resolved multiomics of human cardiac niches.

The function of a cell is defined by its intrinsic characteristics and its niche: the tissue microenvironment in which it dwells. Here we combine single-cell and spatial transcriptomics data to discover cellular niches within eight regions of the human heart. We map cells to microanatomical locations and integrate knowledge-based and unsupervised structural annotations. We also profile the cells of the human cardiac conduction system1. The results revealed their distinctive repertoire of ion channels, G-protein-coupled receptors (GPCRs) and regulatory networks, and implicated FOXP2 in the pacemaker phenotype. We show that the sinoatrial node is compartmentalized, with a core of pacemaker cells, fibroblasts and glial cells supporting glutamatergic signalling. Using a custom CellPhoneDB.org module, we identify trans-synaptic pacemaker cell interactions with glia. We introduce a druggable target prediction tool, drug2cell, which leverages single-cell profiles and drug-target interactions to provide mechanistic insights into the chronotropic effects of drugs, including GLP-1 analogues. In the epicardium, we show enrichment of both IgG+ and IgA+ plasma cells forming immune niches that may contribute to infection defence. Overall, we provide new clarity to cardiac electro-anatomy and immunology, and our suite of computational approaches can be applied to other tissues and organs.

Differentiation and function of cardiac valves in the adult Drosophila heart.

Drosophila, like all insects, has an open circulatory system for the distribution of haemolymph and its components. The circulation of the haemolymph is essentially driven by the pumping activity of the linear heart. The heart is constructed as a tube into which the haemolymph is sucked and pumped forward by rhythmic contractions running from the posterior to the anterior, where it leaves the heart tube. The heart harbours cardiac valves to regulate flow directionality, with a single heart valve differentiating during larval development to separate the heart tube into two chambers. During metamorphosis, the heart is partially restructured, with the linear heart tube with one terminal wide-lumen heart chamber being converted into a linear four-chambered heart tube with three valves. As in all metazoan circulatory systems, the cardiac valves play an essential role in regulating the direction of blood flow. We provide evidence that the valves in adult flies arise via transdifferentiation, converting lumen-forming contractile cardiomyocytes into differently structured valve cells. Interestingly, adult cardiac valves exhibit a similar morphology to their larval counterparts, but act differently upon heart beating. Applying calcium imaging in living specimens to analyse activity in valve cells, we show that adult cardiac valves operate owing to muscle contraction. However, valve cell shape dynamics are altered compared with larval valves, which led us to propose our current model of the opening and closing mechanisms in the fly heart.

Anatomical and biometric study of the mitral valve apparatus: application in valve repair surgery.

OBJECTIVE: Most mitral valve repair techniques provide excellent surgical results by removing regurgitation, but all of these techniques simultaneously reduce posterior valve mobility. A comprehensive biometric study of the mitral valve apparatus will provide landmarks that would help improve this posterior valve mobility. MATERIALS AND METHODS: Thirty one (31) human hearts have been studied, from 14 women and 17 men. The characteristics of the studied sample were analyzed descriptively. The difference in means of the variables between women and men were tested using a Student t test. Correlations between the different measures were determined by simple regression analysis. Mean values are shown with ± 1 standard deviation and the limit of significance was set at 0.05. RESULTS: The mean weight of the hearts was 275.3 ± 2.4 g. The anteroposterior diameter of the mitral annulus was 29.3 ± 1.22 mm, the intertrigonal distance was 25.2 ± 3.50 mm and the anterior leaflet to posterior leaflet ratio was 1.9 ± 0.10, the length of the chordae A2 = 19.4 ± 1.15 mm and P2 = 14.5 ± 0.85 mm. The length of the anterior papillary muscle averaged 30.9 ± 7.20 mm and that of the posterior one 30.0 ± 8.75 mm. The comparison of the different values measured between women and men showed no statistically significant difference (p > 0.05). There was no correlation between these different measured values (p > 0.05). CONCLUSION: A perfect knowledge of anatomy and biometry is therefore essential to offer alternative techniques that reproduce the real anatomy and physiology with a complete reconstruction of the mitral valve.

Computed tomographic evaluation of heart size in clinically healthy cats.

Background: Computed tomography (CT) is currently one of the most useful diagnostic imaging tools for evaluating cardiac disorders in humans and animals. However, studies concerning CT and the feline heart remain scarce. Aim: To create measuring techniques for the feline heart size on CT and to determine the relationships of feline heart size observed on CT with internal parameters including age, bodyweight (BW), and sex. Methods: Four parameters observed on CT including thoracic height/width ratio (THW), relative heart area (RHA), CT vertebral heart score (ctVHS), transverse vertebral heart score (tVHS) in 1.25 mm slice thickness, and both pre- and post-contrast enhanced images were examined. Additionally, radiographic vertebral heart score (rVHS) was also evaluated. Results: THW was significantly influenced by age (p < 0.05). RHA was affected by age and gonadal status of cats (p = 0.001 and p = 0.016, respectively). Age also significantly affected tVHS (p = 0.038). Interestingly, ctVHS was not influenced by age, sex, gonadal status, or BW. tVHS and ctVHS had significantly moderately positive correlations with rVHS (r = 0.476; p = 0.048 and r = 0.6112; p = 0.011, respectively). THW and RHA had non-significant correlations with rVHS (r = 0.2642; p = 0.302 and r = 0.1920; p = 0.455, respectively). Conclusion: CT heart size evaluation can be performed in both pre- and post-contrast enhanced images of 1.25 mm slice thickness. tVHS and ctVHS are recommended parameters for evaluating feline heart size in clinical practice.

Microcirculatory changes as a hallmark of aging in the heart and kidney / Cambios microcirculatorios como sello distintivo del envejecimiento en el corazón y riñón

SUMMARY: Changes in the microcirculation of multiple tissues and organs have been implicated as a possible mechanism in physiological aging. In particular, vascular endothelial growth factor is a secretory protein responsible for regulating angiogenesis via altering endothelial proliferation, survival, migration, extracellular matrix degradation and cell permeability. The aim of the present study was to evaluate the role of vascular endothelial growth factor in the progression of morphological alterations caused by physiological aging in the heart and kidney and to examine its relation to changes in capillary density. We used two age groups of healthy Wistar rats - 6- and 12-month- old. The expression of vascular endothelial growth factor was examined through immunohistochemistry and immunofluorescence and assessed semi-quantitatively. Changes in capillary density were evaluated statistically and correlated with the expression of vascular endothelial growth factor. We reported stronger immunoreactivity for vascular endothelial growth factor in the left compared to the right ventricle and also observed an increase in its expression in both ventricles in older animals. Contrasting results were reported for the renal cortex and medulla. Capillary density decreased statistically in all examined structures as aging progressed. The studied correlations were statistically significant in the two ventricles in 12-month-old animals and in the renal cortex of both age groups. Our results shed light on some changes in the microcirculation that take place as aging advances and likely contribute to impairment in the function of the examined organs.

Los cambios en la microcirculación de múltiples tejidos y órganos se han implicado como un posible mecanismo en el envejecimiento fisiológico. En particular, el factor de crecimiento endotelial vascular es una proteína secretora responsable de regular la angiogénesis mediante la alteración de la proliferación endotelial, la supervivencia, la migración, la degradación de la matriz extracelular y la permeabilidad celular. El objetivo del presente estudio fue evaluar el papel del factor de crecimiento del endotelio vascular en la progresión de las alteraciones morfológicas causadas por el envejecimiento fisiológico en el corazón y riñón y examinar su relación con los cambios en la densidad capilar. Utilizamos dos grupos de ratas Wistar sanas: 6 y 12 meses de edad. La expresión del factor de crecimiento del endotelio vascular se examinó mediante inmunohistoquímica e inmunofluorescencia y se evaluó semicuantitativamente. Los cambios en la densidad capilar se evaluaron estadísticamente y se correlacionaron con la expresión del factor de crecimiento del endotelio vascular. Informamos una inmunorreactividad más fuerte para el factor de crecimiento endotelial vascular en el ventrículo izquierdo en comparación con el derecho y también observamos un aumento en su expresión en ambos ventrículos en animales mayores. Se informaron resultados contrastantes para la corteza renal y la médula. La densidad capilar disminuyó estadísticamente en todas las estructuras examinadas a medida que avanzaba el envejecimiento. Las correlaciones estudiadas fueron estadísticamente significativas en los dos ventrículos en animales de 12 meses y en la corteza renal de ambos grupos de edad. Nuestros resultados arrojan luz sobre algunos cambios en la microcirculación que tienen lugar a medida que avanza el envejecimiento y probablemente contribuyan a un deterioro en la función de los órganos examinados.

Como eu faço no Coração de Atleta: avaliação dos diferentes tipos de adaptação ao exercício / My approach to "Athlete'S Heart": evaluation of the different types of adaptation to exercise

A prática regular de esportes pode induzir adaptações no coração, sendo essa condição comumente chamada de "coração de atleta". As alterações observadas incluem dilatação das câmaras cardíacas, aumento da espessura miocárdica, melhora do enchimento ventricular, aumento da trabeculação do ventrículo esquerdo (VE), dilatação da veia cava inferior, entre outras. Essas alterações também podem ser observadas em algumas doenças cardíacas, como cardiomiopatia (CMP) dilatada, hipertrófica e outras. Dessa forma, os exames de imagem cardíaca são fundamentais na identificação dessas alterações e na diferenciação entre o "coração de atleta" e uma possível cardiopatia.(AU)

Exercise-induced adaptation may occur in amateur and professional athletes. This condition is commonly named "athlete's heart". The alterations observed include dilation of the heart chambers, increased myocardial thickness, improved ventricular filling, increased left ventricular trabeculation, dilation of the inferior vena cava, among others. These changes can also be observed in some heart diseases, such as dilated, hypertrophic and other cardiomyopathies (CMP). Thus, cardiac imaging tests are fundamental in identifying these alterations and in differentiating between "athlete's heart" and possible heart disease. (AU)