ABSTRACT
Several studies show that portions of intramyocardial coronary arteries are spared of arteriosclerosis, involving morphological, embryological, biochemical and pathophysiological aspects. Endothelial function is significantly affected in the segment of transition, as estimated by the vasoactive response to Ach. These findings suggest that myocardial bridge can provide protection against arteriosclerosis by counteracting the negative effects of endothelial dysfunction. The intramyocardial portion's protection phenomenon deserves further scientific research on all research fronts. Improved morphological, biomechanical and especially physiological and embryological knowledge may be the key to a future window of opportunity for chronic arterial disease therapy and prevention. In addition, this review discusses possible therapeutic approaches for symptomatic coronary ischemia caused by myocardial bridges.
Diversos estudos demonstram que as porções intramiocárdicas das artérias coronárias são poupadas da arteriosclerose, envolvendo aspectos morfológicos, embriológicos, biomecânicos e aspectos fisiopatológicos. A função endotelial é significativamente afetada no segmento de transição, tal como estimado pela resposta vasoativa para acetilcolina (Ach). Esses achados sugerem que ponte miocárdica pode fornecer proteção contra a arteriosclerose, por contrariar os efeitos negativos da disfunção endotelial. O fenômeno dessa proteção da porção intramiocárdica merece maior investigação científica em todas as frentes de pesquisa. Maiores conhecimentos sobre os aspectos morfológicos, biomecânicos e, principalmente, fisiológicos e embriológicos podem ser a chave para uma futura janela de oportunidades de terapia e prevenção da doença arterial crônica. Nessa revisão, discutem-se, também, possíveis abordagens terapêuticas para fenômenos coronarianos isquêmicos causados por pontes miocárdicas.
Subject(s)
Humans , Coronary Artery Disease/prevention & control , Endothelium, Vascular/physiopathology , Myocardial Bridging/pathology , Adipose Tissue/metabolism , Coronary Circulation/physiology , Coronary Vessels/anatomy & histology , Coronary Vessels/embryology , Endothelin-1/metabolism , Paracrine Communication/physiology , Peptidyl-Dipeptidase A/metabolismABSTRACT
The formation of the coronary vasculature is a fundamental event in heart development and involves a series of carefully regulated temporal events that include vasculogenesis and angiogenesis. This review focuses the knowledge concerning the formation of the coronary arteries available so far and some molecular mechanisms involved in this process. Understanding coronary embryogenesis is important for interventions regarding adult cardiovascular diseases as well as those necessary to correct heart congenital defects. The insight of the coronary artery development as a result of ingrowth changed the understanding of several congenital coronary artery variations and anomalies described in gross anatomy.
La formación de la vascularización coronaria es un acontecimiento fundamental en el desarrollo del corazón e implica una serie de eventos temporales cuidadosamente regulados que incluyen vasculogénesis y angiogénesis. Esta revisión se focaliza en el conocimiento sobre la formación de las arterias coronarias y algunos mecanismos moleculares implicados en este proceso. Entender la embriogénesis coronaria es importante para las intervenciones relacionadas con las enfermedades cardiovasculares en los adultos, así como también, para corregir defectos congénitos del corazón. La idea del desarrollo de la arteria coronaria, como resultado del crecimiento interno, cambió la comprensión de diversas variaciones y anomalías congénitas de estas arterias descritas en la anatomía macroscópica.
Subject(s)
Humans , Male , Female , Coronary Vessels/anatomy & histology , Coronary Vessels/embryology , Coronary Vessels/ultrastructure , Morphogenesis/genetics , Neovascularization, Physiologic/physiologyABSTRACT
El objetivo de este estudio fue describir la conformación interna y externa y la irrigación del corazón del delfín franciscana de la Plata (Pontoporia blainvillei) para lo cual fueron disecados 12 corazones. El pericardio se fijaba caudalmente al diafragma, ventralmente al músculo transverso torácico y, lateralmente, a las costillas y músculos intercostales. El corazón era aplastado dorsoventralmente, su base era craneal, su ápex era compartido por ambos ventrículos. El ventrículo izquierdo era de pared gruesa, mientras que la del ventrículo derecho más delgada y depresible. La cara ventral correspondía a la cara auricular y la cara dorsal a la cara atrial de la Nomina Anatomica Veterinaria, 2005 (NAV). En la conformación interior del atrio derecho destacaba el gran desarrollo de la cresta terminal y de la fosa oval. Dentro del ventrículo derecho, los músculos papilares se distribuían en subbarterioso, magnus y parvi. Una trabécula septomarginal se extendía entre los músculos papilares subarterioso y magnus. También fueron observadas trabéculas menores del mismo tipo, situadas más ventralmente a la anterior. Las venas pulmonares se unían en un tronco común antes de llegar al atrio izquierdo. El ventrículo izquierdo tenía dos músculos papilares bien desarrollados. La irrigación cardíaca arterial mostraba un predominio de la arteria coronaria izquierda y se notaba la presencia de anastomosis intercoronarias.
The aim of this study is to describe the external and internal conformation and the arterial irrigation of La Plata Dolphin's heart (Pontoporia blainvillei). Twelve animals obtained from nets of fishing ships were used and their hearts were studied by means of simple dissection. The pericardium was fixed caudally to the diaphragm, ventrally to the thoracic transverse muscle and laterally to the ribs and intercostal muscles. The heart weighted about 115 grams, was flattened dorsoventrally, its base was cranial, its apex was shared by both ventricles. The ventral face corresponds to the auricular face of the Nomina Anatomica Veterinaria (NAV), and the dorsal face corresponds to the atrial face. In the internal conformation of the right atrium the great development of the crista terminalis and the fossa ovalis stood out. Inside the right ventricle the papillaris muscles were observed distributed in subarteriosus, magnus and parvi. The dextra septomarginal trabecules were multiple and situated between the papillaris muscles. In the left ventricle they had two well developed papillaris muscles. The left coronary artery is the most important vessel in the arterial irrigation of the cardiac territory.
Subject(s)
Animals , Heart/anatomy & histology , Heart/growth & development , Coronary Vessels/anatomy & histology , Coronary Vessels/embryology , Dolphins/anatomy & histology , Dolphins/embryology , Uruguay/ethnologyABSTRACT
Paciente de 6 anos de idade, portadora de uma fístula entre a artéria coronária esquerda e a cavidade ventricular direita. O trajeto fistuloso, com 1 cm de diâmetro, tinha início no tronco da artéria coronária esquerda, junto a origem de seus ramos descendente anterior e circunflexo, caminhando através da espessura da parede miocárdica até o ápice do coraçäo, onde se abria na cavidade ventricular. O diagnóstico de fístula coronária foi estabelecido no pré-operatório, através de estudos ecocardiográfico e cineangiográfico. Durante a cirurgia foi possível constatar que o trajeto fistuloso era paralelo à artéria descendente anterior e que dele näo se originava nenhum ramo ventricular. O túnel fistular foi aberto em suas duas extremidades e foram suturados seus orifícios, junto à coronária esquerda e junto ao ventrículo direito, com retalhos de pericárdio bovino. Näo houve sinais clínicos ou laboratoriasi de isquemia miocárdica e a paciente apresentou boa evoluçäo pós-operatória
Subject(s)
Humans , Female , Child , Coronary Vessels/surgery , Arteriovenous Fistula/surgery , Cineangiography , Coronary Vessels/embryology , Arteriovenous Fistula/embryology , Arteriovenous FistulaABSTRACT
Twenty seven human embryos from stages 15 to 23 (postsomitic period), belonging to the collection of the "UFR Biomédicale des Saints-Peres, Université René Descartes Paris V", were studied. Details of the aorticopulmonary cleavage were analysed specially aortic valve development and origin of the coronary artery. At stage 18 the aortic valve was clearly distinguished (cup-shaped) presenting semilunar valves and aortic sinus (Valsalvae); at this stage the left coronary artery was detected in 66.7 per cent of the cases as an endothelial epicardial invagination. At stage 19, the left and right coronary arteries were detected simultaneously in 100 per cent of the cases. At stage 20, the coronary arteries showed greater structural complexity with a coat of mesenchymal cells. These results agree with previous data from different embryological collections. These findings suggest that the left coronary artery has a tendency to develop earlier than the right. We found no evidence of the coronary origin from the aortic umen. This work provides additional information about the embryological development of the heart, obtained from the analyses of a French collection of human embryos