A combination of problems that lead to heart center problems is called atrioventricular canal defect. This is a congenital (present at birth) condition and children born with this congenital heart defect have a hole in the wall between the chambers of the heart. Problems with heart valves that control blood flow also are present.
This condition allows increased blood flow to the lungs, which causes the heart muscle to work too hard leading to enlarged muscle of the heart.
If you ignore the symptoms and do not get treatment for an atrioventricular canal defect, it may lead to pulmonary hypertension (high blood pressure in the lungs) and heart failure. Commonly, treatments for this condition involve surgery to repair the valves and close the hole in the heart. Sometimes, this congenital heart defect is called atrioventricular septal defect (AVSD) or endocardial cushion defect.
Symptoms
This congenital heart defect may affect only the two upper chambers of the heart or all four. According to the part of the heart that is affected (partial or complete), symptoms occur. However, both types cause an increased blood flow to the lungs.
Complete Defect
In such cases, the atrioventricular canal defect negatively affects all four chambers of the heart. The symptoms often appear within a few weeks of life. Check below some symptoms:
- Lack of appetite
- Poor weight gain
- Extreme tiredness (fatigue)
- Hyperhidrosis (excessive sweating)
- Breathing problems
- Skin color changes due to reduced oxygen levels
- Irregular or fast heartbeat
- Swelling in the ankles, feet, or legs
- Wheezing
Partial Defect
People with this type of condition may not experience symptoms until early adulthood. However, in such cases, the disease impacts the two upper heart chambers only. The symptoms usually occur due to complications including heart valve problems, pulmonary hypertension, or heart failure. Check below some symptoms:
- Extreme tiredness
- Weakness
- Nausea
- Lack of appetite
- Persistent cough or wheezing
- Fast or irregular heartbeat (arrhythmia)
- Shortness of breath
- Decreased ability to exercise
- Swelling in the feet, arms, or ankles
- Chest pain (angina) or pressure
If any of the previous symptoms occur, immediately visit a doctor.
Causes
This condition often appears after birth when the heart of the baby is developing and healthcare providers do not know the exact cause of this condition. Your risk of developing an atrioventricular canal defect increases if Down syndrome is present.
How Does the Heart Normally Work?
To understand better atrioventricular canal defects, it is important to know how the heart works in normal circumstances.
In healthy people, the heart is divided into four chambers. For example atria (the two upper chambers) and ventricles (the two lower chambers). Therefore, the right side of the heart moves blood to the lungs where it gets oxygen, then oxygen-rich blood flows back to the left side of the heart and into the body’s major artery (aorta). After that, the blood goes throughout the body.
Furthermore, the blood flow is controlled by heart valves that open to let the blood in and then close to prevent the blood from returning.
What Occurs in People with an Atrioventricular Canal Defect?
Complete Atrioventricular Canal Defect
- In such cases, a large hole appears in the center of the heart and it is located between the lower and upper chambers of the heart.
- A combination of oxygen-rich and oxygen-poor blood happens through the hole.
- People with complete atrioventricular canal defects have one large valve between the upper and lower chambers instead of two separate.
- Thereafter, the blood leaks through this large valve into the lower chambers of the heart. As a result, the heart should work harder to pump blood, which causes the heart muscle to become enlarged.
Partial Atrioventricular Canal Defect
- The hole appears between the two upper chambers in the heart’s wall in people with this type of atrioventricular canal defect.
- Certain changes occur only in the mitral and tricuspid valves.
- Those valve changes prevent them from closing properly
- Irregular valve opening may lead to the blood flow in the wrong way.
- In most cases, the mitral valve is negatively affected.
Risk Factors
Check below some factors that could elevate your risk of developing an atrioventricular canal defect:
- Rubella (also called German measles) – Pregnant women with rubella may negatively affect the developing heart of the baby.
- Diabetes – Problems with the baby’s developing heart may occur if the biological mother has diabetes and does not manage it during pregnancy. However, gestational diabetes does not elevate the risk of congenital heart disease.
- Alcohol use – Drinking alcoholic beverages during pregnancy is directly linked with an increased risk of heart defects in the baby.
- Smoking – It is not allowed to smoke, especially during pregnancy because it may increase the baby’s risk of congenital heart defects.
- Certain medications – There are some medications that may cause heart problems or other birth defects in the baby. That’s why you should ask your doctor before taking any medicines or supplements during pregnancy.
- Genetics – Commonly, congenital heart disease runs in families and it is linked with multiple genetic syndromes. For example, most children with Down syndrome have congenital heart defects.
What Are The Potential Complications of an Atrioventricular Canal Defect?
People with this condition may also experience some complications, especially without treatment. Examples include:
- Pulmonary hypertension (high blood pressure in the lungs) – The lungs get an increased amount of blood in people with atrioventricular canal defects due to the hole in the heart center.
- Respiratory tract infections – The hole in the heart may also cause recurrent respiratory infections.
- Heart enlargement – This complication occurs due to increased blood flow that puts extra strain on the heart muscle making it beat harder.
- Heart failure – In people who do not treat this condition, the heart cannot pump enough blood for the body. Therefore, heart failure occurs.
While treatment for this congenital heart defect improves the children’s outlook, complications may occur later in life. Examples include:
- Narrowing of the heart valves
- Irregular heart rhythms (arrhythmia)
- Lung damage that causes trouble breathing
- Valve regurgitation (leaky heart valves)
People who had surgery for an atrioventricular canal defect before serious damage to the lungs usually can have a successful pregnancy. Generally, it is not recommended to become pregnant if you have serious lung or heart damage before the surgery. That’s why you should discuss with your healthcare provider about possible complications and risks before pregnancy.
Prevention
However, it is not possible to prevent an atrioventricular canal defect because some heart disorders run in families. It means you will inherit the congenital heart defect from your biological parents. Generally, it is advised to consult with a genetic counselor and a cardiologist before pregnancy.
Diagnosis
Sometimes, it is possible to diagnose an atrioventricular canal defect during pregnancy by using ultrasound or special heart imaging. However, after birth, the symptoms usually appear within a few weeks. Check below some tests used to confirm the condition:
- Echocardiogram – This test uses sound waves to make images of the heart in motion. It may help identify a hole in the heart or heart valve problems.
- Chest X-ray – This test is used to get detailed images of the lungs and heart. It helps determine if the heart is enlarged or lungs contain extra blood or other fluid.
- Electrocardiogram – This quick test helps measure the electrical activity of the heart.
- Pulse oximetry – This test involves a specific sensor that is placed on the tip of your finger to measure the oxygen level in the blood.
- Cardiac catheterization – This test is used to measure the pressure in different heart parts.
Treatment
In most cases, to treat a partial or complete atrioventricular canal defect doctors recommend surgery. During this procedure, surgeons will use one or two patches to close the hole in the heart wall. After that, these patches become a part of the heart’s wall because the lining of the heart grows over them. Sometimes, doctors may recommend other surgeries but it depends on the atrioventricular canal defect type you experience and other existing heart problems.
Commonly, those who have corrective surgery for this congenital heart defect, do not need more surgery. However, they may experience some complications including heart valve leaks that need treatment.
Frequently Asked Questions
What is the most common genetic syndrome associated with an atrioventricular canal defect?
Most children with Down syndrome also develop an atrioventricular canal defect. Usually, the primary defect of the heart occurs in a part called endocardial cushions that do not develop normally during pregnancy.
What is the main treatment for people with an atrioventricular canal defect?
Healthcare providers usually recommend surgery to close the hole in the heart for both types of the condition. However, some people need additional treatments if heart problems continue after surgery. Discuss with your doctor for more details.
What are the complications of an atrioventricular canal defect?
These include:
- Arrhythmia (irregular heart rhythm)
- Wheezing
- Anorexia
- Sweating
- Swelling of the belly (abdomen) or legs
- Poor weight gain
- Fast breathing
- Extreme tiredness (fatigue)
- Skin color changes
If your child experiences any of the previous complications, immediately visit your healthcare professional. If you have any other questions, ask your physician.
