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Robert H Anderson - One of the best experts on this subject based on the ideXlab platform.
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clinical anatomy of the aortic root
Heart, 2000Co-Authors: Robert H AndersonAbstract:The aortic valve, and its supporting ventricular structures, form the centrepiece of the heart. All chambers of the heart are related directly to the valve, and its leaflets are incorporated directly into the Cardiac Skeleton. As such, the valve is the focus for the echocardiographer. Yet still the precise structure of its component parts remains controversial, with persisting disagreements relating largely to the enigmatic “annulus”. Indeed, it is difficult to find an unequivocal definition of the annulus, a structure appearing most frequently in the context of Cardiac surgery.1 This review describes the arrangement of the aortic root in terms of the attachment of the aortic valvar leaflets, and their relations to the aorta and its ventricular support.2 Recognising that these parts will still be considered to represent an annulus, I will try to show that the ring like structure thus described has considerable length, encompassing the entirety of the semilunar attachments of the leaflets. It is the recognition of the relation of these attachments to the anatomic and haemodynamic ventriculo-arterial junctions which is the key to understanding.3 Although forming the outlet from the left ventricle, when viewed in the context of the heart as it lies within the chest (“attitudinally correct orientation”4), the aortic root is positioned to the right and posterior relative to the subpulmonary infundibulum (fig 1). The subpulmonary infundibulum is a complete muscular funnel which supports in uniform fashion the leaflets of the pulmonary valve.5 In contrast, the leaflets of the aortic valve are attached only in part to the muscular walls of the left ventricle. This is because the aortic and mitral valvar orifices are fitted alongside each other within the circular short axis profile of the left ventricle, as compared to the tricuspid and pulmonary valves which occupy opposite ends …
Cs Rutland - One of the best experts on this subject based on the ideXlab platform.
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Discovery of os cordis in the Cardiac Skeleton of chimpanzees (Pan troglodytes)
'Springer Science and Business Media LLC', 2020Co-Authors: Moittié S, Baiker K, Cousins E, White K, Liptovszky M, Redrobe S, Alibhai A, Cj Sturrock, Cs RutlandAbstract:Cardiovascular diseases, especially idiopathic myocardial fibrosis, is one of the most significant causes of morbidity and mortality in captive great apes. This study compared the structure and morphology of 16 hearts from chimpanzees (Pan troglodytes) which were either healthy or affected by myocardial fibrosis using X-ray microtomography. In four hearts, a single, hyperdense structure was detected within the right fibrous trigone of the Cardiac Skeleton. High resolution scans and histopathology revealed trabecular bones in two cases, hyaline cartilage in another case and a focus of mineralised fibro-cartilaginous metaplasia with endochondral ossification in the last case. Four other animals presented with multiple foci of ectopic calcification within the walls of the great vessels. All hearts affected by marked myocardial fibrosis presented with bone or cartilage formation, and increased collagen levels in tissues adjacent to the bone/cartilage, while unaffected hearts did not present with os cordis or cartilago cordis. The presence of an os cordis has been described in some ruminants, camelids, and otters, but never in great apes. This novel research indicates that an os cordis and cartilago cordis is present in some chimpanzees, particularly those affected by myocardial fibrosis, and could influence the risk of Cardiac arrhythmias and sudden death
Rutland, Catrin Sian - One of the best experts on this subject based on the ideXlab platform.
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Discovery of os cordis in the Cardiac Skeleton of chimpanzees (Pan troglodytes)
'Springer Science and Business Media LLC', 2020Co-Authors: Moittié Sophie, Baiker Kerstin, Strong Victoria, Cousins Emma, White Kate, Liptovszky Mátyás, Redrobe Sharon, Alibhai Aziza, Sturrock, Craig J., Rutland, Catrin SianAbstract:© 2020, The Author(s). Cardiovascular diseases, especially idiopathic myocardial fibrosis, is one of the most significant causes of morbidity and mortality in captive great apes. This study compared the structure and morphology of 16 hearts from chimpanzees (Pan troglodytes) which were either healthy or affected by myocardial fibrosis using X-ray microtomography. In four hearts, a single, hyperdense structure was detected within the right fibrous trigone of the Cardiac Skeleton. High resolution scans and histopathology revealed trabecular bones in two cases, hyaline cartilage in another case and a focus of mineralised fibro-cartilaginous metaplasia with endochondral ossification in the last case. Four other animals presented with multiple foci of ectopic calcification within the walls of the great vessels. All hearts affected by marked myocardial fibrosis presented with bone or cartilage formation, and increased collagen levels in tissues adjacent to the bone/cartilage, while unaffected hearts did not present with os cordis or cartilago cordis. The presence of an os cordis has been described in some ruminants, camelids, and otters, but never in great apes. This novel research indicates that an os cordis and cartilago cordis is present in some chimpanzees, particularly those affected by myocardial fibrosis, and could influence the risk of Cardiac arrhythmias and sudden death
Gómez Torres, Fabián Alejandro - One of the best experts on this subject based on the ideXlab platform.
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Análisis de la microestructura del sistema de conducción cardíaco basado en histología y análisis de imagen. Descripción en el humano y otras especies animales
2021Co-Authors: Gómez Torres, Fabián AlejandroAbstract:El sistema de conducción cardíaca es una estructura ramificada que permite el inicio y la rápida propagación de impulsos eléctricos que desencadenan la despolarización eléctrica del tejido miocárdico. Los nodos cardíacos son la fuente del impulso eléctrico que se transmite al corazón y la función principal del sistema de conducción ventricular es la activación eléctrica rápida de los ventrículos. El objetivo de este trabajo fue estudiar las características histológicas y morfométricas de los diferentes componentes del sistema de conducción Cardiaco en humanos, cerdos, caballos y perros, así como sus posibles variaciones. Se utilizó un grupo de diez corazones de humanos, diez de cerdo, diez de caballo y cinco de perro sin antecedentes clínicos de patologías cardíacas. La región de los nodos Cardiacos se seccionó en serie y se extrajo el bloque de tejido para su estudio. Los ventrículos izquierdos se disecaron y se seccionaron en tres cortes de igual ancho (base, tercio medio y ápex). Se obtuvieron cortes histológicos de 5 μm de espesor y se tiñeron con hematoxilina-eosina y tricrómico de Masson y las células de Purkinje y sus uniones se identificaron mediante desmina y la tinción de PAS. Sobre estas muestras se realizó la adquisición de las imágenes con un microscopio óptico Leica DMD108 y se evaluaron mediante un análisis morfométrico con el software Image-ProPlus 7,1. El nodo sinoatrial en humanos y cerdos es una estructura compacta, cuya forma es ovoide. La longitud del nodo sinoatrial en humanos está entre 1,7-7,4 mm y en cerdos se encuentra entre 1,3-3 mm. Las células P son grandes, pálidas y ubicadas en el centro o la periferia. El diámetro máximo de las células P en humanos (9,9 µm) es significativamente mayor que en cerdos (8,9 µm) (p=0,026). El nodo atrioventricular tiene una forma ovoide en humanos y cerdos. En caballos y perros la forma del nodo es triangular. La longitud del nodo atrioventricular en humanos se encuentra entre 1,7-2,5 mm, en cerdos entre 1,4-2,6 mm, en caballos entre 1,6-2,7 mm y en perros entre 1,1-3,1 mm. Observamos una disminución del tamaño del nodo, un aumento de las fibras de colágeno y una disminución del tamaño y el número de células P dentro del nodo atrioventricular en los cerdos, caballos y perros cuando presentaban cartílago en el esqueleto fibroso Cardiaco. En cerdos las células P (25,3 µm) presentan un diámetro máximo significativamente mayor que en humanos (5,2 µm) (p=0,001). Se encontraron diferencias significativamente mayores en el diámetro máximo de las células P del nodo atrioventricular en los corazones que no presentaron cartílago en el esqueleto fibroso Cardiaco (p=0,002). Las fibras de Purkinje fueron difíciles de identificar en humanos, en su mayoría mostraban un color más oscuro o igual al de los cardiomiocitos y ocasionalmente se observaban con un tono más pálido. Las fibras de Purkinje en humanos se encontraron en el subendocardio y en los cerdos en el miocardio y subendocardio. Las fibras de Purkinje se ubicaron principalmente en la región septal en todas las especies estudiadas. Las uniones Purkinje-miocardio estuvieron presentes en el 10% de todas las micrografías analizadas en humanos y en el 24,2% en cerdos. El diámetro máximo de las células de Purkinje fue significativamente mayor en cerdos (22,85 µm) que en humanos (18,52 µm) (p=0.031). El análisis morfométrico nos ha permitido cuantificar objetivamente cada uno de los componentes del sistema de conducción Cardiaco y compararlos en las diferentes especies. La menor densidad celular en cualquiera de los nodos cardíacos, especialmente en las células P del nodo sinoatrial, puede disminuir la conducción eléctrica dentro de los nodos y en los tractos internodales. Además, la presencia de metaplasia cartilaginosa en el esqueleto fibroso cardíaco disminuye el tamaño del nodo atrioventricular y sus células y aumenta el porcentaje de fibras de colágeno dentro del nodo, lo que reflejaría la presencia de arritmias cardíacas derivadas de la mala conducción. El estudio de las fibras y células de Purkinje y sus uniones miocárdicas es vital para conocer su distribución normal en las especies analizadas.The Cardiac conduction system is a branched structure that allows the initiation and rapid propagation of electrical impulses that trigger electrical depolarization of myocardial tissue. The Cardiac nodes are the source of the electrical impulse that is transmitted to the heart and the main function of the ventricular conduction system is the rapid electrical activation of the ventricles. The objective of this work was to study the histological and morphometric characteristics of the different components of the Cardiac conduction system in humans, pigs, horses and dogs, as well as their possible variations. A group of ten hearts from humans, ten from pigs, ten from horses and five from dogs with no clinical history of Cardiac pathologies was used. The region of the Cardiac nodes was sectioned serially and the tissue block was removed for study. The left ventricles were dissected and divided into three sections of equal width (base, middle third, and apex). 5 μm thick histological sections were obtained and stained with hematoxylin-eosin and Masson's trichrome, and Purkinje cells and their junctions were identified by desmin and PAS staining. Images were acquired on these samples with a Leica DMD108 optical microscope and evaluated by morphometric analysis with Image-ProPlus 7.1 software. The sinoatrial node in humans and pigs is a compact structure, the shape of which is ovoid. The length of the sinoatrial node in humans is between 1.7-7.4 mm and in pigs it is between 1.3-3 mm. P cells are large, pale, and located in the center or periphery. The maximum diameter of P cells in humans (9.9 µm) is significantly larger than in pigs (8.9 µm) (p=0.026). The atrioventricular node has an ovoid shape in humans and pigs. In horses and dogs the shape of the node is triangular. The length of the atrioventricular node in humans is between 1.7-2.5 mm, in pigs between 1.4-2.6 mm, in horses between 1.6-2.7 mm and in dogs between 1.1-3.1 mm. We observed a decrease in node size, an increase in collagen fibers, and a decrease in the size and number of P cells within the atrioventricular node in pigs, horses, and dogs when they presented cartilage in the fibrous Cardiac Skeleton. P cells (25.3 µm) have a significantly larger maximum diameter in pigs than in humans (5.2 µm) (p=0.001). Significantly greater differences were found in the maximum diameter of the P cells of the atrioventricular node in hearts that did not present cartilage in the fibrous Cardiac Skeleton (p=0.002). Purkinje fibers were difficult to identify in humans, mostly showing a darker color than or equal to that of cardiomyocytes, and occasionally being seen with a paler hue. Purkinje fibers in humans were found in the subendocardium and in pigs in the myocardium and subendocardium. Purkinje fibers were located mainly in the septal region in all species studied. Purkinje-myocardial junctions were present in 10% of all micrographs analyzed in humans and in 24.2% in pigs. The maximum diameter of the Purkinje cells was significantly greater in pigs (22.85 µm) than in humans (18.52 µm) (p=0.031). Morphometric analysis has allowed us to objectively quantify each of the components of the Cardiac conduction system and compare them in different species. The lower cell density in any of the Cardiac nodes, especially in the P cells of the sinoatrial node, can decrease electrical conduction within the nodes and in the internodal tracts. Furthermore, the presence of cartilaginous metaplasia in the Cardiac fibrous Skeleton decreases the size of the atrioventricular node and its cells and increases the percentage of collagen fibers within the node, reflecting the presence of Cardiac arrhythmias derived from poor conduction. The study of Purkinje cells and fibers and their myocardial junctions is vital to know their normal distribution in the species analyzed
Moittié Sophie - One of the best experts on this subject based on the ideXlab platform.
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Discovery of os cordis in the Cardiac Skeleton of chimpanzees (Pan troglodytes)
'Springer Science and Business Media LLC', 2020Co-Authors: Moittié Sophie, Baiker Kerstin, Strong Victoria, Cousins Emma, White Kate, Liptovszky Mátyás, Redrobe Sharon, Alibhai Aziza, Sturrock, Craig J., Rutland, Catrin SianAbstract:© 2020, The Author(s). Cardiovascular diseases, especially idiopathic myocardial fibrosis, is one of the most significant causes of morbidity and mortality in captive great apes. This study compared the structure and morphology of 16 hearts from chimpanzees (Pan troglodytes) which were either healthy or affected by myocardial fibrosis using X-ray microtomography. In four hearts, a single, hyperdense structure was detected within the right fibrous trigone of the Cardiac Skeleton. High resolution scans and histopathology revealed trabecular bones in two cases, hyaline cartilage in another case and a focus of mineralised fibro-cartilaginous metaplasia with endochondral ossification in the last case. Four other animals presented with multiple foci of ectopic calcification within the walls of the great vessels. All hearts affected by marked myocardial fibrosis presented with bone or cartilage formation, and increased collagen levels in tissues adjacent to the bone/cartilage, while unaffected hearts did not present with os cordis or cartilago cordis. The presence of an os cordis has been described in some ruminants, camelids, and otters, but never in great apes. This novel research indicates that an os cordis and cartilago cordis is present in some chimpanzees, particularly those affected by myocardial fibrosis, and could influence the risk of Cardiac arrhythmias and sudden death