ABSTRACT
Coronary artery embryology In early fetal development, the primitive loosely packed myocardium is nourished via sinusoids, which communicate with the heart cavities. Persistence of these sinusoids may lead to coronary artery cameral fistulae. As the myocardium becomes more compact, these sinusoids disappear and give rise to a network of veins, arteries and capillaries (approximately 32 days of gestation) which may have connections with other mediastinal vessels. Persistence of these connections may lead to coronary artery fistula. As the coronary artery network evolves, endothelial buds arise from the base of the truncus arteriosus. It is unclear if there are only two buds, or buds from each potential cusp of the aortic and pulmonary sinuses (six buds) with later involution of all but two buds. These buds later grow and join the coronary artery network (developing from the sinusoids) to establish the definitive coronary artery system. Abnormal involution (in the case of six initial buds), bud position or septation of the truncus arteriosus may lead to the development of an abnormal origin of the coronary arteries.
