Valve of the inferior vena cava
Encyclopedia
The valve of the inferior vena cava (Eustachian valve) lies at the junction of the inferior vena cava and right atrium.
In fetal life, the Eustachian valve helps direct the flow of oxygen-rich blood
through the right atrium into the left atrium
via the foramen ovale
(preventing blood flowing into the right ventricle). Before birth, oxygen rich blood returning from the placenta mixes with blood from the hepatic veins in the inferior vena cava. Streaming this blood across the atrial septum via the foramen ovale increases the oxygen content of blood in the left atrium. This in turn increases the oxygen concentration of blood in the left ventricle, the aorta, the coronary circulation and the circulation of the developing brain.
Following birth and separation from the placenta, the oxygen content in the inferior vena cava falls. With the onset of breathing, the left atrium receives oxygen-rich blood from the lungs via the pulmonary veins. As blood flow to the lungs increases, the amount of blood flow entering the left atrium increases. When the pressure in the left atrium exceeds the pressure in the right atrium, the foramen ovale begins to close and limits the blood flow between the left and right atrium. While the Eustachian valve persists in adult life, it essentially does not have a specific function.
There is a large variability in size, shape, thickness, and texture of the persistent eustachian valve, and in the extent to which it encroaches on neighboring structures such as the atrial septum. At one end of the spectrum, the embryonic eustachian valve disappears completely or is represented only by a thin ridge. Most commonly, it is a crescentic fold of endocardium arising from the anterior rim of the IVC orifice. The lateral horn of the crescent tends to meet the lower end of the crista terminalis, while the medial horn joins the thebesian valve, a semicircular valvular fold at the orifice of the coronary sinus. At the other extreme, it persists as a mobile, elongated structure projecting several centimeters into the right atrial cavity. In this case, it may demonstrate an undulating motion in real time echocardiography; and when it is quite large, it may be confused with right atrial tumors, thrombi, or vegetations. Occasionally, the eustachian valve crosses the floor of the right atrium from the orifice of the IVC and inserts into the lower portion of the interatrial septum adjacent to the atrioventricular valves. However, higher insertion of a giant eustachian valve, which mimics the echocardiographic appearance of divided right atrium, is very rare. This type of abnormality may be confused with cor triatriatum
dexter. Very rarely, such a configuration of a large eustachian valve may mimic a right atrial cystic tumor.
(born between 1500 and 1513, died 1574).
Association between Eustachian valve and patent foramen ovale has been studied in patient with cryptogenic stroke.
In fetal life, the Eustachian valve helps direct the flow of oxygen-rich blood
Blood
Blood is a specialized bodily fluid in animals that delivers necessary substances such as nutrients and oxygen to the cells and transports metabolic waste products away from those same cells....
through the right atrium into the left atrium
Left atrium
The left atrium is one of the four chambers in the human heart. It receives oxygenated blood from the pulmonary veins, and pumps it into the left ventricle, via the mitral valve.-Foramen ovale:...
via the foramen ovale
Foramen ovale (heart)
In the fetal heart, the foramen ovale , also ostium secundum of Born or falx septi, allows blood to enter the left atrium from the right atrium. It is one of two fetal cardiac shunts, the other being the ductus arteriosus...
(preventing blood flowing into the right ventricle). Before birth, oxygen rich blood returning from the placenta mixes with blood from the hepatic veins in the inferior vena cava. Streaming this blood across the atrial septum via the foramen ovale increases the oxygen content of blood in the left atrium. This in turn increases the oxygen concentration of blood in the left ventricle, the aorta, the coronary circulation and the circulation of the developing brain.
Following birth and separation from the placenta, the oxygen content in the inferior vena cava falls. With the onset of breathing, the left atrium receives oxygen-rich blood from the lungs via the pulmonary veins. As blood flow to the lungs increases, the amount of blood flow entering the left atrium increases. When the pressure in the left atrium exceeds the pressure in the right atrium, the foramen ovale begins to close and limits the blood flow between the left and right atrium. While the Eustachian valve persists in adult life, it essentially does not have a specific function.
There is a large variability in size, shape, thickness, and texture of the persistent eustachian valve, and in the extent to which it encroaches on neighboring structures such as the atrial septum. At one end of the spectrum, the embryonic eustachian valve disappears completely or is represented only by a thin ridge. Most commonly, it is a crescentic fold of endocardium arising from the anterior rim of the IVC orifice. The lateral horn of the crescent tends to meet the lower end of the crista terminalis, while the medial horn joins the thebesian valve, a semicircular valvular fold at the orifice of the coronary sinus. At the other extreme, it persists as a mobile, elongated structure projecting several centimeters into the right atrial cavity. In this case, it may demonstrate an undulating motion in real time echocardiography; and when it is quite large, it may be confused with right atrial tumors, thrombi, or vegetations. Occasionally, the eustachian valve crosses the floor of the right atrium from the orifice of the IVC and inserts into the lower portion of the interatrial septum adjacent to the atrioventricular valves. However, higher insertion of a giant eustachian valve, which mimics the echocardiographic appearance of divided right atrium, is very rare. This type of abnormality may be confused with cor triatriatum
Cor triatriatum
Cor triatriatum is a congenital heart defect where the left atrium or right atrium is subdivided by a thin membrane, resulting in three atrial chambers . The membrane may be complete or may contain one or more fenestrations of varying size...
dexter. Very rarely, such a configuration of a large eustachian valve may mimic a right atrial cystic tumor.
History
The Eustachian valve, also called valvulae venae cavae inferioris, was described for the first time by the Italian anatomist Bartolomeo EustachiBartolomeo Eustachi
Bartolomeo Eustachi , also known by his Latin name of Eustachius, was one of the founders of the science of human anatomy.-Life:...
(born between 1500 and 1513, died 1574).
Echocardiography
The Eustachian valve is frequently seen with transthoracic echocardiography from the parasternal long axis, the apical four-chamber and the sub-costal four-chamber views. The Eustachian valve better seen with transesophageal echocardiography in the bi-caval view and right sided horizontal and longitudinal views.Association between Eustachian valve and patent foramen ovale has been studied in patient with cryptogenic stroke.