| Persistent left superior vena cava | |
|---|---|
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| The (right) superior vena cava (on left) and the left brachiocephalic vein (here labeled as left innominate vein). The left superior vena cava is not shown in this image. |
In anatomy, a persistent left superior vena cava is the most common variation of the thoracic venous system. [1] [2] It is present in between 0.3% and 0.5% of the population, [3] [4] [5] and is an embryologic remnant that results from a failure to involute.
In persistent left superior vena cava, the left brachiocephalic vein does not develop fully and the left upper limb and head and neck drain into the right atrium via the coronary sinus. [5]
In isolation, the variation is considered benign, but is very frequently associated with cardiac abnormalities (e.g. ventricular septal defect, atrioventricular septal defect) that have a significant mortality and morbidity. [4] [6] It is more frequent in patients with congenital heart defects. [7]
The (right) superior vena cava is almost always unaffected by the presence of persistent left superior vena cava. [4] [5]
If an anomaly is detected during a routine ultrasound, a fetal echocardiogram is performed to determine whether a fetus has the condition. [8] Otherwise, it is often unnoticed unless an extenuating circumstance warrants further examination of the heart, usually much later in life.[ citation needed ]
CT and MRI scans in a parasagittal section may show a "pipe" sign where the left superior vena cava occurs. [4]
If no other cardiac abnormalities are present, persistent left superior vena cava will not be treated, as it is usually asymptomatic and unharmful. [4] If it drains into the left atrium, then deoxygenated blood enters the circulation to the body, and cyanosis may occur. [8]
Veins are blood vessels in the circulatory system of humans and most other animals that carry blood toward the heart. Most veins carry deoxygenated blood from the tissues back to the heart; exceptions are those of the pulmonary and fetal circulations which carry oxygenated blood to the heart. In the systemic circulation arteries carry oxygenated blood away from the heart, and veins return deoxygenated blood to the heart.
The left and right brachiocephalic veins are major veins in the upper chest, formed by the union of each corresponding internal jugular vein and subclavian vein. This is at the level of the sternoclavicular joint. The left brachiocephalic vein is nearly always longer than the right.
The superior vena cava (SVC) is the superior of the two venae cavae, the great venous trunks that return deoxygenated blood from the systemic circulation to the right atrium of the heart. It is a large-diameter (24 mm) short length vein that receives venous return from the upper half of the body, above the diaphragm. Venous return from the lower half, below the diaphragm, flows through the inferior vena cava. The SVC is located in the anterior right superior mediastinum. It is the typical site of central venous access via a central venous catheter or a peripherally inserted central catheter. Mentions of "the cava" without further specification usually refer to the SVC.
Cardiopulmonary bypass (CPB) is a technique in which a machine temporarily takes over the function of the heart and lungs during surgery, maintaining the circulation of blood and oxygen to the body. The CPB pump itself is often referred to as a heart–lung machine or "the pump". Cardiopulmonary bypass pumps are operated by perfusionists. CPB is a form of extracorporeal circulation. Extracorporeal membrane oxygenation is generally used for longer-term treatment.
Atrial septal defect (ASD) is a congenital heart defect in which blood flows between the atria of the heart. Some flow is a normal condition both pre-birth and immediately post-birth via the foramen ovale; however, when this does not naturally close after birth it is referred to as a patent (open) foramen ovale (PFO). It is common in patients with a congenital atrial septal aneurysm (ASA).
The Fontan procedure or Fontan–Kreutzer procedure is a palliative surgical procedure used in children with univentricular hearts. It involves diverting the venous blood from the inferior vena cava (IVC) and superior vena cava (SVC) to the pulmonary arteries without passing through the morphologic right ventricle; i.e., the systemic and pulmonary circulations are placed in series with the functional single ventricle. The procedure was initially performed in 1968 by Francis Fontan and Eugene Baudet from Bordeaux, France, published in 1971, simultaneously described in 1971 by Guillermo Kreutzer from Buenos Aires, Argentina, and finally published in 1973.
Cardiac catheterization is the insertion of a catheter into a chamber or vessel of the heart. This is done both for diagnostic and interventional purposes.
The atrium is one of two upper chambers in the heart that receives blood from the circulatory system. The blood in the atria is pumped into the heart ventricles through the atrioventricular valves.
The chordae tendineae , colloquially known as the heart strings, are inelastic cords of fibrous connective tissue that connect the papillary muscles to the tricuspid valve and the mitral valve in the heart.
Tricuspid atresia is a form of congenital heart disease whereby there is a complete absence of the tricuspid valve. Therefore, there is an absence of right atrioventricular connection. This leads to a hypoplastic (undersized) or absent right ventricle. This defect is contracted during prenatal development, when the heart does not finish developing. It causes the systemic circulation to be filled with relatively deoxygenated blood. The causes of tricuspid atresia are unknown.
The coronary sinus is the largest vein of the heart. It drains over half of the deoxygenated blood from the heart muscle into the right atrium. It begins on the backside of the heart, in between the left atrium, and left ventricle; it begins at the junction of the great cardiac vein, and oblique vein of the left atrium. It receives multiple tributaries. It passes across the backside of the heart along a groove between left atrium and left ventricle, then drains into the right atrium at the orifice of the coronary sinus.
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.
A sinus venosus atrial septal defect is a type of atrial septal defect primarily associated with the sinus venosus.
In the anatomy of the heart, the smallest cardiac veins, also known as the Thebesian veins, are small valveless veins in the walls of all four heart chambers that drain venous blood into any of the heart chambers.
The bidirectional Glenn (BDG) shunt, or bidirectional cavopulmonary anastomosis, is a surgical technique used in pediatric cardiac surgery procedure used to temporarily improve blood oxygenation for patients with a congenital cardiac defect resulting in a single functional ventricle. Creation of a bidirectional shunt reduces the amount of blood volume that the heart needs to pump at the time of surgical repair with the Fontan procedure.
Anomalous pulmonary venous connection is a congenital defect of the pulmonary veins.
Hypoplastic right heart syndrome is a congenital heart defect in which the right atrium and right ventricle are underdeveloped. This defect causes inadequate blood flow to the lungs and thus, a blue or cyanotic infant.
Congenital stenosis of vena cava is a congenital anomaly in which the superior vena cava or inferior vena cava has an aberrant interruption or coarctation.
Heart development, also known as cardiogenesis, refers to the prenatal development of the heart. This begins with the formation of two endocardial tubes which merge to form the tubular heart, also called the primitive heart tube. The heart is the first functional organ in vertebrate embryos.
Raghib syndrome is rare a congenital heart defect where the left superior vena cava (LSVC) is draining into the left atrium in addition to an absent coronary sinus and an atrial septal defect. This can be considered a dangerous heart condition because it puts the individual at a high risk of stroke. Other defects that are often associated with Raghib syndrome can include ventricular septal defects, enlargement of the tricuspid annulus, and pulmonary stenosis. While this is considered an extremely rare developmental complex, cases regarding a persistent left superior vena cava (PLSVC) are relatively common among congenital heart defects. It is also important to note that the PLSVC often drains into the right atrium, and only drains into the left atrium in approximately 10 to 20% of individuals with the defect.