Coarctation of the aorta is a birth defect in which part of the aorta is lighter than usual. If the narrowing is severe enough and goes undiagnosed, the baby may have serious problems and may need surgery or other procedures shortly after birth. For this aim, coarctation of the aorta is often considered a critical congenital heart fault. The defect happens when a baby's aorta does not form correctly as the baby grows and matures during pregnancy. Narrowing of the aorta usually occurs in the part of the blood vessel just after the arteries branch out to carry blood to the head and arms, near the patent ductus arteriosus, although occasionally the narrowing occurs before or after the ductus arteriosus. In some babies with coarctation, some of the tissue from the wall of the ductus arteriosus is thought to mix with tissue from the aorta. When the tissue tightens and lets the ductus arteriosus to close normally after birth, this extra tissue can also tauten and narrow the aorta.

The narrowing or coarctation blocks normal blood movement to the body. This can reverse flow into the heart's left ventricle, making the muscles in this ventricle work harder to draw blood out of the heart. Since the narrowing of the aorta is usually localized after the arteries branch to the upper body, coarctation in this region can lead to normal or high blood pressure and blood pulses in the head and arms and low blood pressure. and weak pulses in the legs and inferior body.

If the condition is very severe, not enough blood may reach the lower body. The extra work on the heart can cause the walls of the heart to thicken to pump harder. This eventually weakens the heart muscle. If the aorta doesn't widen, the heart can become weak enough to cause heart failure. Coarctation of the aorta often occurs with other inherited heart defects.

Causes of coarctation of the aorta

In most children, the cause is unknown. Some children may have other heart defects along with the coarctation.

How does it affect the heart?

The coarctation blocks blood flow from the heart to the lower body. Blood pressure rises above constriction. Blood pressure is much higher than normal in the left pumping chamber (left ventricle), and the heart must work harder to pump blood through the constriction in the aorta. This can cause thickening (hypertrophy) and damage to the overloaded heart muscle.

Symptoms of coarctation of the aorta

Symptoms depend on the severity of the narrowing. Severe cases are often diagnosed at birth or during the first months of life. In slight cases, the individual may be symptom-free into adulthood. Symptoms in an adult may include exercise intolerance, headache, shortness of breath, chest pain, nosebleeds, cold leg or foot pain after exercise, or difficult-to-control high blood pressure (hypertension).

Treatment

Most newborns with symptoms will have surgery right after birth or shortly thereafter. They will first receive medications to stabilize them.

Children who are diagnosed when they are big will also need surgery. In most cases, the symptoms are not as severe, so it may take more time to plan for surgery.

During surgery, the narrow part of the aorta will be removed or opened.

If the problem area is small, the two free ends of the aorta can be reconnected. This is called an end-to-end anastomosis.

If a large part of the aorta is removed, a graft or one of the patient's own arteries can be used to fill the space. The implant can be artificial or from a cadaver.

Sometimes physicians will try to stretch and open the narrow part of the aorta using a balloon that extends into the blood vessel. This type of procedure is named a balloon angioplasty. It can be done in place of surgery, but has a higher failure rate.

Older children generally need medicine to treat high blood pressure after surgery. Some will need lifelong treatment for this problem.

Diagnosis of coarctation of the aorta

Coarctation of the aorta is present from birth. The age at which coarctation is noticed depends on the severity of the narrowing.

In about 25 percent of isolated coarctation cases, the narrowing is severe enough to cause symptoms in the first days of life when the ductus arteriosus closes. When the ductus arteriosus closes, the left ventricle must unexpectedly pump against a much higher resistance and this can lead to heart failure and shock. Because these newborns are fine until the ductus arteriosus closes, symptoms appear quickly and are often severe.

In patients who do not develop heart failure in childhood, the coarctation may not be detected until the child is several years old. In these elderly patients, a coarctation is often first suspected due to a heart murmur or high blood pressure.

Coarctation is suspected when the doctor cannot feel the pulses in a child's legs. High blood pressure can be detected in the arms (but not the legs). A heart murmur is usually present and may be strongest in the back (where the aorta is located).

The diagnosis of coarctation is usually long-established with echocardiography, which can define the anatomy of the aorta and appraise other cardiac abnormalities that may also be present. Occasionally, other tests, such as a cardiac MRI or CT scan, may be used to test the presence of a coarctation.

Management of coarctation

In a seriously ill newborn, the goals of treatment are to improve ventricular function and restore blood flow to the lower body. A continuous intravenous drug, prostaglandin (PGE-1), is used to open the ductus arteriosus (and keep it in an open state) letting blood flow to the body beyond the coarctation. Often times, it is also necessary to start intravenous medications that improve the contraction of the heart muscle. Babies will almost always need a ventilator before surgery.

In symptomatic neonates with coarctation, surgical repair is usually performed urgently after initial stabilization. In rare cases, a baby will not improve with medical therapy, and surgery must be done before the baby has stabilized.

There are several surgical techniques to repair the coarctation. A common repair involves resection (removal) of the narrow area with anastomosis (reconnection) of the two ends to each other. This repair is called an end-to-end anastomosis. Another common repair involves taking the aorta after the area of ​​narrowing and anastomizing it with the ascending aorta. This type of repair is called arch advancement and is done when there is more diffuse hypoplasia. Less normally, the narrowing can be opened with a patch, or a portion of an artery can be used as a flap to expand the area (called a subclavian flap aortoplasty).

Because older children may have minimal symptoms, repair of the coarctation is generally planned electively. Surgical repair is most often performed with resection of the narrowed segment and end-to-end reconnection.

In older children, an alternative to surgery may be catheter therapy. In selected cases, the area of ​​narrowing can be dilated with a balloon. In some patients, the coarctation can be treated very effectively with the placement of a metal stent. Because stents do not grow, this therapy is generally used in older and larger patients. The availability of covered stents, under investigation in the United States, will likely improve the safety and efficacy of coarctation stenting in the future.

Risk factor's

Coarctation of the aorta often occurs in conjunction with other congenital heart defects. Certain heart circumstances are often related with coarctation, including:

Bicuspid aortic valve. The aortic valve splits the lower left chamber (left ventricle) of the heart from the aorta. A bicuspid aortic valve has two flaps (cusps) in its place of the usual three. Many persons with coarctation of the aorta have a bicuspid aortic valve.

Subaortic stenosis. Subaortic stenosis occurs when there is a narrowing of the area below the aortic valve that obstructs blood flow from the left ventricle to the aorta. This narrowing can be in the form of a fibrous membrane.

Patent ductus arteriosus. The ductus arteriosus is a blood vessel that connects the baby's left pulmonary artery to the aorta. It allows blood to not pass through the lungs while the baby grows in the womb. Shortly after birth, the ductus arteriosus usually closes. If it breaks open, it's called a patent ductus arteriosus.

Holes in the wall amid the left and right sides of the heart. Some people are born with a hole in the wall (septum) between the upper chambers of the heart (atrial septal defect) or the lower chambers of the heart (ventricular septal defect). This causes oxygen-rich blood on the left side of the heart to mix with oxygen-poor blood on the right side of the heart.

Congenital stenosis of the mitral valve. The mitral valve is positioned between the upper and lower left heart chambers. Allow blood to flow through the left side of your heart. In mitral valve stenosis, the valve narrows. As a result, the movement of blood between the upper and lower left chambers of the heart is reduced, which increases the pressure in the upper left chamber (atrium). Oxygen-rich blood from the lungs returns to the heart through veins that adhere to the upper left chamber. Increased pressure in the left atrium can cause symptoms of pulmonary congestion. These symptoms include shortness of breath, shortness of breath during exercise, and shortness of breath when lying down.

Coarctation of the aorta is more common in men than women, as well as those who have certain genetic conditions, such as Turner syndrome.

Complications

Without treatment, coarctation of the aorta often leads to complications. In babies, it can lead to heart failure or death.

High blood pressure is the most mutual long-term difficulty of coarctation of the aorta. Blood pressure regularly drops after the aortic coarctation has been repaired, but it may still be higher than usual.

Other complications of coarctation of the aorta can include:

• A weakened or bulging artery in the brain (brain aneurysm) or bleeding in the brain (hemorrhage)
• Aortic tear or tear (dissection)
• Enlargement in a segment of the wall of the aorta (aneurysm)
• Heart failure
• Premature coronary artery disease - narrowing of the blood vessels supplying the heart
• Race

If the coarctation of the aorta is severe, your heart may not be able to pump enough blood to your other organs. This can cause heart damage and can lead to kidney failure or other organ failure.

Complications are also likely after treatment for coarctation of the aorta. They include:

• New narrowing of the aorta (new coarctation, possibly years after treatment)
• Hypertension
• Aneurysm or aortic rupture
• You will need lifelong follow-up for coarctation of the aorta and may need additional treatments.

Prevention

Coarctation of the aorta cannot be prevented because it is usually present at birth. However, if you or your child have a condition that increases the risk of aortic coarctation, such as Turner syndrome, bicuspid aortic valve, or other heart defect, or a family history of congenital heart disease, early uncovering can help. Deliberate the risk of aortic coarctation with your Cardiologist.