Coarctation of the Aorta
Circulatory Disorder Project --- By: Courtney Chapman
Description of the Disorder
Thousands of babies are born in the United States with circulatory disorders each year, and one of the most common of these is coarctation of the aorta (1). The aorta is is the large blood vessel that branches off the heart and functions to deliver oxygen-rich blood throughout the body (3). The Mayo Clinic defines coarctation of the aorta as, "a narrowing, or constriction, in a portion of the aorta" (2). Because of this problem, the left ventricle of the heart is forced to pump harder to generate a higher pressure in order to get blood through the aorta and to the rest of the body (1,2,4).
The picture below is a diagram of a heart with a coarctation in the aorta. The maximized picture on the right shows how much blood is trying to get through the aorta and, because of the coarctation, how little blood can actually get through.
Symptoms of the Disorder
Coarctation of the aorta is a disorder is congenital, which means it is present from birth (3,4). The age at which the disorder is detected depends of whether or not the condition is mild or severe. If the condition is severe, the left ventricle is not strong enough to perform the extra work (4). If the issue goes undetected in infants, then their hearts will undergo congestive heart failure (1,4). In about 25% of cases, the coarctation is enough to be detected within the first few days of a baby's life when the ductus arteriosus closes (5). When it closes, symptoms appear quickly and can be fatal. Coarctation can be diagnosed by several methods:
- Coarctation can be suspected by a doctor when he/she is unable to feel pulses in a baby's legs, or if there is high blood pressure in the arms but not the legs (5).
- If a heart murmur is present and loudest on the back of the baby, coarctation of the aorta can be detected because the aorta is located here (5).
Coarctation of the aorta is confirmed by doctors with an echocardiography, which is an ultrasound test (5,6). The test uses high frequency sound waves to create an image of a heart (6).
Causes of the Disorder
As previously mentioned, coarctation of the aorta is caused by a constriction at some point in the aorta (2). Which in turn, makes the left ventricle pump harder than normal to try and force blood through the narrow portion of the aorta to the rest of the body (1,2,4). This constriction can be caused by a few different things:
- The ductus arteriosus is a blood vessel that is normally present in a fetus and has a special tissue in its wall that causes it to close in the first hours or days of life. In this situation, coarctation can be caused by the presence of extra ductal tissue (4).
- If the aortic arch is too small, coarctation can occur (4).
- Coarctation can occur with other cardiac defects that typically involve the left side of the heart. The two most common defects that occur with coarctation are: 1) bicuspid aortic valve and 2) ventricular septal defect (4).
Treatments for the Disorder
If a newborn baby is showing signs and symptoms of coarctation of their aorta, the baby must be placed on a ventilator and then prepared for surgery (4). There are a few techniques that doctors use to fix the disorder, but the most common is seen in the three pictures below. This method is often called, "end-to-end" (4).
Beginning
In this severe case, the coarctation occurred right in the region where the ductus arteriosus is located in fetal babies (4). Once they are born, this flap no longer exists (4). With more blood flow in the area, some infants are susceptible to coarctation.
Surgery
If a baby is suspected of having a coarctation, then the infant is stabilized and then prepared for surgery immediately. During surgery, doctors remove the narrowed region of the aorta.
End
After removal, "end-to-end" reconstruction takes place (4). Here, the two cut ends of the aorta are sewn together. The baby should be able to live a normal life afterwards.
Prevention
Causes of coarctation of the aorta are actually unknown. Recent studies have suggested that it can be caused by a combination of genes and risk factors, which include specific things that the mother of the baby comes into contact with while pregnant (environment, foods, drinks, medicines, etc.) (7). Although it is considered a "critical congenital heart defect," the disorder only affects about four out of every 10,000 babies born (7).
Youtube Video
Coarctation of the Aorta
This is a short video, only 1 minute and thirty seconds, that was supported by the Cincinnati Children's Hospital. It shows a three-dimensional view of two hearts: one with a coarctation and one without.
Sources
- http://www.livestrong.com/article/129884-circulatory-system-diseases-kids/
- http://www.mayoclinic.org/diseases-conditions/coarctation-of-the-aorta/multimedia/coarctation-of-the-aorta/img-20007864
- http://www.mayoclinic.org/diseases-conditions/coarctation-of-the-aorta/basics/definition/con-20031772
- http://www.cincinnatichildrens.org/health/c/coarctation/
- http://www.cincinnatichildrens.org/patients/child/encyclopedia/defects/coarctation-images/
- http://www.cincinnatichildrens.org/health/e/echo/
- http://www.cdc.gov/ncbddd/heartdefects/coarctationofaorta.html