In
anatomy, a persistent left
superior vena cava is the most common variation of the
thoracic venous system. It is present in between 0.3% and 0.5% of the population,
and is an
embryologic remnant that results from a failure to
involute.
Presentation
In persistent left superior vena cava, the left
brachiocephalic vein does not develop fully and the left
upper limb and
head
A head is the part of an organism which usually includes the ears, brain, forehead, cheeks, chin, eyes, nose, and mouth, each of which aid in various sensory functions such as sight, hearing, smell, and taste. Some very simple animals may ...
and
neck
The neck is the part of the body on many vertebrates that connects the head with the torso. The neck supports the weight of the head and protects the nerves that carry sensory and motor information from the brain down to the rest of the body. In ...
drain into the
right atrium via the
coronary sinus.
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
Mortality is the state of being mortal, or susceptible to death; the opposite of immortality.
Mortality may also refer to:
* Fish mortality, a parameter used in fisheries population dynamics to account for the loss of fish in a fish stock throug ...
and
morbidity.
It is more frequent in patients with
congenital heart defects.
The (right)
superior vena cava is almost always unaffected by the presence of persistent left superior vena cava.
Diagnosis
If an anomaly is detected during a routine
ultrasound, a
fetal echocardiogram is performed to determine whether a fetus has the condition.
Otherwise, it is often unnoticed unless an extenuating circumstance warrants further examination of the heart, usually much later in life.
CT and
MRI scans in a
parasagittal section may show a "pipe" sign where the left superior vena cava occurs.
Treatment
If no other cardiac abnormalities are present, persistent left superior vena cava will not be treated, as it is usually
asymptomatic
In medicine, any disease is classified asymptomatic if a patient tests as carrier for a disease or infection but experiences no symptoms. Whenever a medical condition fails to show noticeable symptoms after a diagnosis it might be considered asy ...
and unharmful.
If it drains into the
left atrium, then
deoxygenated blood enters the circulation to the body, and
cyanosis
Cyanosis is the change of body tissue color to a bluish-purple hue as a result of having decreased amounts of oxygen bound to the hemoglobin in the red blood cells of the capillary bed. Body tissues that show cyanosis are usually in locations ...
may occur.
References
External links
{{Congenital vascular defects
Congenital vascular defects