Coarctation of the aorta is a condition in which the walls of the aorta become pinched, narrowed or pressed together, leading to various degrees of obstruction of blood flow through the blood vessel. The narrowing may be in a specific location, or run along an entire section of the aorta. Aorta coarctation is one of the top five congenital heart defects that occurs at birth.
The age at which coarctation is diagnosed depends on the severity of aorta narrowing and its symptoms. Severe coarctation may be suspected in infants if a physician detects weak or absent pulses in the legs, groin or neck. If the condition is not detected in a newborn, it may go undiagnosed for many years. In milder cases, coarctation may not be detected until adolescence due to lack of symptoms. As the aorta becomes more narrowed, it may cause cold hands or feet, headaches and decreased tolerance for exercise.
Coarctation of the aorta can be treated with surgery or with less-invasive catheter-based methods. If corrected before 10 years of age, the majority of patients are successfully treated, although there is some risk that the aorta may once again narrow later in life. After treatment, patients will likely need to take antibiotics before any dental, medical or surgical procedure to reduce their risk of infection in either the aorta or one of the heart’s four valves(endocarditis). Long-term follow-up by a cardiologist is important for children who have been treated for coarctation to monitor for subsequent cardiac problems, such as hypertension.
About coarctation of the aorta
From the Latin word “to press together,” coarctation of the aorta is a condition in which the walls of the aorta are pinched, narrowed or pressed together. This narrowing may occur in a particular place or may run along a larger section of the aorta.
Most often, the aorta is narrowed just beyond the left subclavian artery, which branches off just after the aorta leaves the heart to transport blood to the left arm. As a result of this narrowing, blood flow to the lower body tends to be reduced, which can lead to low blood pressure (hypotension) in the lower body and legs. In addition, blood flow to the upper body tends to be increased, which raises blood pressure in the upper body and forces the heart to work harder.
Coarctation of the aorta is a deceptively complex defect. While it may appear to be only a narrowed portion of the aorta, in fact the aortic anomaly is often one of many problems related to underdevelopment of the left side of the heart. For instance, patients with coarctation of the aorta have a significant chance of having abnormalities in the bicuspid valve (also known as the mitral valve), which rests between the left atrium and left ventricle. Other ventricular problems, including an undersized aortic arch, are also common. Alternatively, some patients may have a simple or mild coarctation that may not be immediately diagnosed.
Coarctation is a potentially dangerous condition because the aorta is the main artery that carries oxygen-rich blood from the heart to the rest of the body. When any part of this vital artery is narrowed, it can lead to fatal consequences. For example, severe coarctation of the aorta may result in heart failure if the heart is not strong enough to pump blood through the narrow opening. Patients who do not undergo surgery for this condition are unlikely to reach the age of 40.
Potential complications can include the following:
High blood pressure (hypertension).
Enlarged heart.
Progressive kidney failure.
Premature development of coronary artery disease (hardening and narrowing of the coronary arteries).
Aortic aneurysm, which could lead to a potentially fatal aortic rupture if the aneurysm bursts.
Aortic dissection. A tear in the inner lining of the aorta, creating a space between the inner and outer layers. If blood leaks into that space, a variety of potentially fatal conditions could result, including heart attack or stroke.
Bleeding in the brain (intracerebral hemorrhage) or stroke.
Coarctation of the aorta is one of the top five heart defects that occurs at birth, accounting for 6 to 8 percent of all congenital defects. It occurs in approximately 1 out of every 10,000 people and is significantly more common among boys than girls. Furthermore, it has been linked to a genetic disorder in women (Turner syndrome) where one of the two X-chromosomes normally present in women is partially or totally absent. The condition is usually diagnosed in children or adults under 40 years of age.
Signs and symptoms of aortic coarctation
Signs and symptoms of aortic coarcation may not develop until the first week after birth, depending on the severity of the coarctation and other associated conditions. While the majority of patients born with this condition may show symptoms within the first months of life, others survive into early childhood or adolescence without exhibiting symptoms or receiving a diagnosis. These patients may visit their physician complaining of exercise intolerance and may complain of extreme fatigue of the lower extremities.
Signs and symptoms of coarctation of the aorta include:
Peripheral cyanosis. A blue tint to the skin in the lower portion of the body due to lack of oxygen-rich blood in that area (often called blue baby in infants).
High blood pressure in the upper body.
Cold feet or legs and low blood pressure in those extremities.
Weak, delayed or absent femoral artery pulse (the pulse generally felt in the groin area) and stronger carotid artery pulse (felt in the neck).
Other symptoms include:
Dizziness
Headache
Decreased ability to exercise due to leg cramping upon exertion
Fainting (syncope)
Nosebleeds
Diagnosis methods
Coarctation of the aorta is often detected during a newborn’s first physical examination. Sometimes it is not noticed until the natural closure of the ductus arteriosus, a temporary blood vessel that connects the aorta and pulmonary artery before birth. Blood pressure measurements in the arms and legs may be slightly or significantly different from each other, and the parents may have noticed that the child is breathless and failing to thrive. A physician may also detect a heart murmur by listening to the patient’s heart using a stethoscope.
The physician may also be able to detect signs of a narrowed and/or leaky aortic valve or left-sided heart failure. Coarctation of the aorta may occur with other congenital (from birth) heart diseases, such as an atrial septal defect, ventricular septal defect or various valvular heart diseases.
In many cases, the absence of the femoral (groin) pulse may be the only detectable sign immediately after birth. Diagnosis may be confirmed by any of these following tests:
Electrocardiogram (EKG). A recording of the heart’s electrical activity as a graph on a moving strip of paper or video monitor. The highly sensitive electrocardiograph machine can indicate an enlargement (hypertrophy) of the left ventricle, which can be a sign of disease and overwork.
Echocardiogram. A test that uses sound waves to visualize the structures and functions of the heart. A moving image of the patient’s beating heart is played on a video screen, where a physician can study the heart’s thickness, size and function. The image also shows the motion pattern and structure of the four heart valves, revealing any potential leakage (regurgitation) or narrowing (stenosis). During this test, a Doppler ultrasound may also be done to evaluate blood flow in the coronary arteries, the blood vessels of the arms and legs and the carotid arteries in the neck.
Chest x-ray. A radiation-based test that produces a picture of the general size, shape and structure of the heart and lungs. It may show abnormal rib structure, or “notched” ribs.
CAT scan (computed tomography or CT scan). An x-ray that creates a three-dimensional or cross-sectional image through computer technology.
MRI (magnetic resonance imaging test). An imaging test that uses magnetic fields and a computer to produce high-resolution cross-sectional or three-dimensional images of the heart.
Cardiac catheterization. This test includes an aortic angiogram to visualize the location and severity of blockages in the aorta. It uses a special dye administered through a thin tube called a catheter. This dye is visible under x-ray. It is less frequently used than other imaging studies.
Treatment and prevention
The treatment of coarctation of the aorta has generated some controversy within medical circles. It can be treated with less invasive, catheter-based treatments or surgery. However, choosing which procedure is appropriate may be complicated.
The catheter-based treatment for coarctation of the aorta is similar to the balloon angioplasty used for coronary artery disease. During this procedure, a catheter tipped with a balloon is threaded into the aorta, usually through the femoral artery in the leg. Once it has reached the narrowed area of the aorta, the balloon is expanded, forcing the vessel to open. Following angioplasty, a stent, or metal, spring-like coil, may be inserted to help keep the aorta open.
Although the initial success rate is about 90 percent, there is considerable risk when the procedure is performed in newborns (between 5 and 25 percent) that the aorta will constrict once again later in life. Therefore, many physicians believe that infants with coarctation of the aorta should be treated with medication until surgery is feasible. Among older children, however, the reclosure rate is somewhat better (about comparable to surgery), making it a more viable option for older children.
The decision and timing of surgery also present challenges. However, if symptoms are present that do not respond to medical treatment, surgery is almost always indicated.
During the surgical treatment, the narrowed portion of the aorta is removed and the two free ends are sewn back together (surgical anastomosis). If the gap between the two ends is small, it may be bridged with a synthetic graft. Sometimes the gap is patched with a flap of tissue from a nearby blood vessel (often the left subclavian artery). Three to four days of hospitalization is generally required.
Early intervention (before 10 years of age) may improve life expectancy, and almost 70 percent of cases are successfully repaired. A patient’s prognosis after surgery is generally good, but lifetime follow-up and medical management is necessary. For example, patients will need to take antibiotics before any dental, medical or surgical procedure to lower their risk of developing an infection of the aorta or the heart valves (endocarditis). It is also recommended that patients be monitored by a cardiologist to have their blood pressure checked every two years and to make sure the aorta remains unobstructed.
Because it is a congenital (from birth) heart defect, there is no evidence that coarctation of the aorta can be prevented. The long-term effects of surgical repair for many congenital heart conditions are still being studied. However, surgery and a lifetime of follow-up and maintenance offer the hope of a healthy future to more patients than ever before.
Other potential aortic arch defects
The aortic arch is the top portion of the aorta that develops between the fifth and seventh week of pregnancy. Aortic arch syndrome refers to a group of conditions associated with an abnormal structure of one or more of the arteries that branch out from the aortic arch. Symptoms include neurological changes, blood pressure changes, blood clots and reduced pulse. This syndrome can be congenital (from birth) or arise as a complication of coronary artery disease (CAD), blood clots or trauma (such as an accident).
Interrupted aortic arch is another associated condition of the aortic arch in which there is literally an interruption along the aorta. It may occur with ventricular septal defect, another form of congenital heart disease. Surgical repair is usually necessary.
Questions for your doctor
Preparing questions in advance can help patients to have more meaningful discussions with their physicians regarding their conditions. Patients or parents may wish to ask their doctor the following questions about coarctation of the aorta:
Why do you suspect this condition in my child?
What signs may indicate a medical emergency with this condition?
What tests will be done to diagnose coarctation of the aorta?
How will the tests be performed?
Does my child have any other heart defects?
What are my treatment options for coarctation of the aorta?
Will my child need surgery to repair the defect?
How soon must the surgery be performed?
What is the recuperation period following surgery?
Will my child need medications after surgery?
What are the chances the aorta will become narrowed again?
Will my child have any restrictions from the condition?
How will the condition affect my child later in life?
Am I at higher risk for having another child with this condition?
