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Complete Common Atrioventricular Canal Defect, also known as Atrioventricular Septal Defect, is a lack of separation of the atria and the ventricles into separate right and left chambers as well as a lack of separation of the mitral and tricuspid valves. The lack of separation of these two valves results in a single atrioventricular valve.
In patients with atrioventricular canal defect, the single atrioventricular may not close properly. Therefore, the heart must pump an excessive amount of blood and this may result in an enlargement of the heart.
Surgical repair for atrioventricular canal defect is required within the first six months of life. The surgery involves sewing patches over the ASD and VSD and carefully separating the single atrioventricular valve into two valves.
How Does Atrioventricular Canal Defect Differ From
Normal Cardiac Anatomy?
If your child has atrioventricular canal defect the structure of his or her heart is different from normal cardiac anatomy.
Heart With Normal Cardiac Anatomy
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Adobe Flash Player.
When your child has a congenital heart defect, there's usually something wrong with the structure of his or her heart's structure.
The heart is composed of four chambers. The two upper chambers, known as atria, collect blood as it flows back to the heart. The two lower chambers, known as ventricles, pump blood with each heartbeat to the two main arteries (the pulmonary artery and the aorta). The septum is the wall that divides the heart into right and left sides. The atrial septum separates the right and left atria; likewise, the ventricular septum separates the two ventricles.
There are four valves that control the flow of blood through the heart. These flap-like structures allow blood to flow in only one direction. The tricuspid and mitral valves, also known as the atrioventricular valves, separate the upper and lower chambers of the heart. The aortic and pulmonary valves, also known as the arterial valves, separate the ventricles from the main arteries. Oxygen-depleted blood returns from the body and drains into the right atrium via the superior and inferior vena cavas. The blood in the right atrium then passes through the tricuspid valve and enters the right ventricle.
Next, the blood passes through the pulmonary valve, enters the pulmonary artery, and travels to the lungs where it is replenished with oxygen. The oxygen-rich blood returns to the heart via the pulmonary veins, draining into the left atrium. The blood in the left atrium passes through the bicuspid, or mitral, valve and enters the left ventricle.
Finally, the oxygen-rich blood flows through the aortic valve into the aorta and out to the rest of the body.
From Nemours' KidsHealth
- ECG (Electrocardiogram)
- Cardiac Catheterization
- If Your Child Has a Heart Defect
- When Your Child Needs a Heart Transplant
- Heart and Circulatory System
- Congenital Heart Defects Special Needs Factsheet
- Heart Murmurs
- Coarctation of the Aorta
- Congenital Heart Defects
- Atrial Septal Defect
- A to Z: Tetralogy of Fallot
- A to Z: Atrial Flutter
- Patent Ductus Arteriosus (PDA)
- Ventricular Septal Defect
- Tetralogy of Fallot
- A to Z: Patent Ductus Arteriosus (PDA)
- A to Z: Hypoplastic Left Heart Syndrome
Trusted External Resources
Coarctation of the Aorta
What Is Coarctation of the Aorta?
Coarctation of the aorta (COA) is a narrowing of the aorta, the major blood vessel that carries blood away from the heart to the body. This narrowing causes the left side of the heart to work harder to pump blood through the aorta.
Sometimes the coarctation is minor and might not even cause symptoms. Other times, surgery or other procedures are needed to treat it.
What Causes COA?
Coarctation of the aorta is a congenital defect, meaning that a baby is born with it. Doctors aren't sure why some people develop COAs, but boys are almost twice as likely to have it than girls.
In many people, the defect shows up with other birth defects or conditions, such as a ventricular septal defect (a hole in the wall between the heart's left and right ventricles). It's also fairly common in girls born with Turner syndrome, a genetic disorder in which one of a girl's two X chromosomes is incomplete or missing.
Usually, COA is found early. But some people aren't diagnosed until they're teens or even adults. In those cases, it's usually because the narrowing in the aorta is not severe enough to cause serious symptoms until then. But even people who don't have major symptoms need treatment because COA can eventually cause problems. The defect doesn't go away on its own.
What Are the Signs & Symptoms of COA?
Abnormal blood pressure is often the first sign of COA. During a physical exam, a doctor may find that a child with a coarctation has higher blood pressure in the arms than in the legs. The doctor also might hear a heart murmur or notice that the pulse in the groin is weak or hard to feel. Any person diagnosed with high blood pressure should be checked for coarctation of the aorta.
Often, kids don't have any symptoms and the COA is discovered during a regular visit to the doctor. Kids who do have symptoms might have:
- cold legs and feet
- shortness of breath, especially when exercising
- chest pain
How Is Coarctation of the Aorta Diagnosed?
Doctors may refer a child with the signs or symptoms of COA to a pediatric cardiologist (a doctor who specializes in diagnosing and treating heart problems). The cardiologist will listen to the heart, feel the pulses, and check blood pressure.
The cardiologist might order an echocardiogram — a test that uses sound waves to create a picture of the heart and its circulation — and other tests that produce images of the heart, like a chest X-ray, a magnetic resonance imaging (MRI) test, or a computerized tomography (CT) scan.
COA must be treated quickly because it can cause high blood pressure and enlarge the heart. It also can cause dissection or rupture of the aorta, which can be fatal. Severe coarctations usually are found shortly after birth and repaired by surgery immediately.
How Is COA Treated?
Coarctation of the aorta can be repaired with surgery or other procedures. One of the most common ways to fix a coarctation is to remove the narrow section and reconnect the two ends of the aorta.
In some cases, doctors may do a balloon dilation (also called balloon angioplasty). In this procedure, a tiny balloon is inserted into a blood vessel in the leg and a very thin wire is threaded up to the aorta, across the narrow area. When the balloon is inflated, the narrow area is widened. Then the balloon is removed. The cardiologist also may implant a stent to keep the area open after the procedure.
After the defect is fixed, most symptoms of COA disappear right away because the blockage that caused those symptoms is gone. Some people will still have high blood pressure for a while and might have to take medicine to control it.
Kids and teens who have had surgery often feel completely better after a week or two, and those who have had the balloon treatment feel better even sooner, often within a couple of days.
But doctors recommend that all patients avoid some physical activities — especially lifting heavy objects or sports that could cause an impact to the chest — for several weeks or months to give the body enough time to heal. Someone whose blood pressure remains high may have to continue to limit certain activities until the blood pressure lowers.
Kids who've had a COA corrected will need to see their doctors regularly. Sometimes, the narrowing can return after surgery or balloon dilation treatment. Visits to the cardiologist every year or two after recovery will let the doctor monitor blood pressure and look for signs that COA could be returning.
If your child has COA or has had a coarctation repaired, call the doctor if you see shortness of breath, chest pain, or fainting.
Overall, kids who have had coarctation of the aorta can expect to lead a normal life after treatment.
Reviewed by: Steven B. Ritz, MD
Date reviewed: October 30, 2017