What is coarctation of the aorta?
A healthy heart is a strong, muscular pump that pushes blood through the circulatory system to carry oxygen and nutrients to the body. The heart has four chambers -- two on the right and two on the left. Blood is pumped through these chambers and regulated by valves that open and close like tiny doors, so that blood can move in only one direction.
After its trip through the body to deliver oxygen, blood is a blue color because it's no longer oxygen-rich. The blue blood returns to the heart through the right chambers and is pumped through the pulmonary artery into the lungs. In the lungs, it picks up more oxygen and becomes bright red. It then goes back through the pulmonary vein to the left chambers and is pumped through the aorta and out into the body again.
The aorta is the largest blood vessel in the body. It is the passageway for oxygen-rich blood to leave the left side of the heart and carry oxygen and nutrients all through the body. The aorta has three segments: Ascending aorta, transverse aortic arch, and descending aorta.
Coarctation is a narrowing or pinching in the aorta, usually between the aortic arch and descending aorta. It can occur alone but it frequently shows up in combination with other heart defects.
Coarctation of the aorta (also called aortic coarctation) forces your baby's heart to pump harder in order to push blood through the constricted part of the aorta. This causes high blood pressure in the left side of the heart and arms, while the legs are left with low pressure.
In babies with aortic coarctation, the heart may not be able to create the needed level of blood pressure. Left untreated, this condition may have very serious results, such as tearing in the arteries, premature coronary artery disease, a cerebral aneurysm, organ failure, congestive heart failure or death.
What causes coarctation of the aorta?
Coarctation of the aorta occurs during the first eight weeks of fetal development, when the heart is forming. Coarctation of the aorta makes up about 8-11% of all congenital heart defects. The defect appears in boys twice as often as in girls.
Most of the time, aortic coarctation happens with no clear reason for its cause. However, it does occur more often in people with particular genetic conditions, such as Turner's syndrome. As many as one in ten people with Turner's syndrome also have aortic coarctation. Some congenital heart defects may also have a genetic link, causing heart problems to occur more often in certain families.
Coarctation of the aorta often appears alongside other heart defects. Your baby is more likely to have coarctation of the aorta if he or she also has one of the following conditions:
- Bicuspid aortic valve: The aortic valve separates the left ventricle of the heart from the aorta. Typically, the aortic valve is a tricuspid valve. That means if you viewed a cross-section of the valve, it would look like a pie cut into three sections. In order to allow blood to pass, the pie pieces, or cuspids, flap open. In a bicuspid aortic valve, there is only two cuspids. This can prevent the cuspids from opening and closing properly.
- Ventricular septal defect: This is a hole in the wall between the two ventricles of the heart.
- Patent ductus arteriosus: The ductus arteriosus is a blood vessel that lets blood bypass the lungs. It should close after birth, but if it remains open, it's called a patent ductus arteriosus.
Aortic or mitral valve stenosis. This is a narrowing of the valve between the left ventricle of the heart and aorta (aortic stenosis) or the left atrium and left ventricle (mitral stenosis).
What are the signs and symptoms?
In severe cases of coarctatation, the problem is usually diagnosed in infancy. Symptoms vary but may include:
- Pale skin
- Heavy and/or rapid breathing
- Poor appetite and poor weight gain
Your baby's doctor may also suspect a heart defect if he or she hears a heart murmur — an abnormal whooshing noise, heard through a stethoscope exam, which may indicate a problem with blood flow. Most heart murmurs are called "innocent heart murmurs." Children with innocent heart murmurs do not have a heart defect and do not experience heart problems. However, if a heart murmur is present along with other symptoms, your doctor may want to investigate further by ordering other tests.
In mild cases of coarctation, the problem may not be noticed until school age or adolescence. School-aged children with mild aortic coarctation may experience headaches, lower body cramps, high blood pressure or no symptoms at all.
Some mild cases of aortic coarctation may not even become apparent until early adulthood (20s or 30s), when otherwise healthy-seeming adults may experience:
- High blood pressure (hypertension) in the arms
- Shortness of breath, especially during exercise
- Cold feet, cramping and muscle weakness in the legs
- Headaches and nosebleeds
How is it diagnosed?
A clear diagnosis is the first step to treatment. A pediatric cardiologist (a children's heart doctor) can use several tests to confirm your child's diagnosis. These tests may include:
- Chest X-ray: A beam of electromagnetic energy creates images on film that show the inside structures of your baby's body. A chest X-ray may show an enlarged heart or an indention in the aorta at the site of the coarctation.
- Cardiac magnetic resonance imaging (MRI): This test produces a three-dimensional image of the heart so you're your child's doctors can examine blood flow and functioning of the heart as it is working. An MRI of the chest will reveal the location of the coarctation and determine whether it affects other blood vessels.
- Electrocardiogram (ECG or EKG): This test, conducted by attaching patches with wires (electrodes) to your baby's skin, records the heart's electrical activity. It will show if there are abnormal heart rhythms (arrhythmias or dysrhythmias) and/or stress on the heart muscle. If the coarctation of the aorta is severe, the electrocardiogram will demonstrate evidence of a thickened heart muscle (ventricular hypertrophy).
- Echocardiogram (Echo): This test uses sound waves to make a moving image of the heart on a video screen. It is similar to an ultrasound and may help detect the location and severity of the aortic coarctation and can help diagnose other heart defects, such as a bicuspid aortic valve.
- Cardiac catheterization: During this procedure, your doctor inserts a thin flexible tube (a catheter) into a blood vessel in the groin, then guides it up to the inside of the heart. A dye injected through the catheter makes the heart structures visible on x-ray pictures. The catheter also measures blood pressure and oxygen levels. Cardiac catheterization helps determine the severity of the aortic coarctation.
- How is it treated?
Most children born with aortic coarctation will live healthy, active lives once the defect is repaired.
In a severe case, your child may be very sick and need to stay in the intensive care unit (ICU) in preparation for an emergency repair of the coarctation. Your child may be given medications to improve blood flow until the repair can be done.
In a mild case, your child may exhibit fewer initial symptoms, and the repair procedure can be scheduled for a later date.
Either way, coarctation of the aorta generally requires a repair of the narrowed vessel. Repair procedures vary depending on your child's individual needs, but in general, two types of procedures may be used:
- Balloon angioplasty: This procedure is similar to the cardiac catheterization described in the diagnostic tests above, except your doctor will inflate a tiny balloon in the constricted segment of the aorta to stretch and widen it. A small tube called a "stent" may be placed in the narrowed area to keep the aorta open.
- Surgical repair: In a surgical repair of your child's aortic coarctation, the surgeon will remove the narrowed section of the aorta and sew the two remaining portions together. The surgery may be different depending on the situation. Some surgeries use a patch, a tube, or a small piece of another artery to reconnect the aorta.
After surgery, your child's doctor may recommend antibiotics to prevent infection. In some cases, other medications may be necessary to maintain low blood pressure.
Occasionally, the aorta may become constricted again as your child grows. If this happens, the balloon procedure or surgery may be needed again.
About treatment for coarctation at Children's
Aortic coarctation is treated through Children's cardiovascular program one of the largest and oldest pediatric cardiovascular programs in the region. Team members consistently achieve treatment results that are among the best in the nation. Each year, care is provided for thousands of the region¹s sickest children with heart conditions, including fetuses, newborns, infants, children, adolescents, and adult, long-term patients with pediatric cardiovascular conditions.
For more information, please call Children's Heart Clinic at 1-800-938-0301.
(From Pritchet & Hull Assoc., Inc.)
Heart with coarctation of the aorta
(From Pritchet & Hull Assoc., Inc.)