Congenital Heart Diseases
The vast majority of congenital heart defects have no known cause. Mothers will often wonder if something they did during the pregnancy caused the heart problem. In most cases, nothing can be attributed to the heart defect. Some heart problems do occur more often in families, so there may be a genetic link to some heart defects. Some heart problems are likely to occur if the mother had a disease while pregnant and was taking medications, such as anti-seizure medicines. However, most of the time, there is no identifiable reason as to why the heart defect occurred.
Congenital heart problems range from simple to complex. Some heart problems can be watched by the baby's physician and managed with medicines, while others will require surgery, sometimes as soon as in the first few hours after birth. A baby may even "grow out" of some of the simpler heart problems, such as patent ductus arteriosus (PDA) or atrial septal defect (ASD), since these defects may simply close up on their own with growth. Other babies will have a combination of defects and require several operations throughout their lives.
Types of Congenital heart diseases:
- Artrial Septal Defect
- Ventrical Septal Defect
Kids with an atrial septal defect (ASD) have an opening in the wall (septum) between the atria. As a result, some oxygenated blood from the left atrium flows through the hole in the septum into the right atrium, where it mixes with oxygen-poor blood and increases the total amount of blood that flows toward the lungs. The increased blood flow to the lungs creates creates a swishing sound, known as a heart murmur. This heart murmur, along with other specific heart sounds that can be detected by a cardiologist, may be clues that a child has an ASD.
ASDs can be located in different places on the atrial septum, and they can be different sizes. The symptoms and medical treatment of the defect will depend on those factors. In some rare cases, ASDs are part of more complex types of congenital heart disease. It's not clear why, but ASDs are more common in girls than in boys.
Causes
ASDs occur during fetal development of the heart and are present at birth. During the first weeks after conception, the heart develops. If a problem occurs during this process, a hole in the atrial septum may result.
In some cases, the tendency to develop a ASD may be genetic. There can be genetic syndromes that cause extra or missing pieces of chromosomes that can be associated with ASD. For the vast majority of children with a defect, however, there's no clear cause of the ASD.
Signs and Symptoms
The size of an ASD and its location in the heart will determine what kinds of symptoms a child experiences. Most children who have ASDs seem healthy and appear to have no symptoms. Generally, kids with an ASD feel well and grow and gain weight normally. Infants and children with larger, more severe ASDs, however, may possibly show some of the following signs or symptoms:
- poor appetite
- poor growth
- fatigue
- shortness of breath
- lung problems and infections, such as pneumonia
If an ASD is not treated, health problems can develop later, including an abnormal heart rhythm (known as an atrial arrhythmia) and problems in how well the heart pumps blood. As kids with ASDs get older, they may also be at an increased risk for stroke, since a blood clot that develops can pass through the hole in the wall between the atria and travel to the brain. Pulmonary hypertension (high blood pressure in the lungs) may also develop over time in older patients with larger untreated ASDs.
Fortunately, most kids with ASD are diagnosed and treated long before the heart defect causes physical symptoms. Because of the complications that ASDs can cause later in life, pediatric cardiologists often recommend closing ASDs early in childhood.
Diagnosis
Generally, a child's doctor hears the heart murmur caused by ASD during a routine checkup or physical examination. ASDs are not always diagnosed as early in life as other types of heart problems, such as ventricular septal defect (a hole in the wall between the two ventricles). The murmur caused by an ASD is not as loud and may be more difficult to hear than other types of heart murmurs, so it may be diagnosed any time between infancy and adolescence (or even as late as adulthood).
If a doctor hears a murmur and suspects a heart defect, the child may be referred to a pediatric cardiologist, a doctor who specializes in diagnosing and treating childhood heart conditions. If an ASD is suspected, the cardiologist may order one or more of the following tests:
- chest X-ray, which produces an image of the heart and surrounding organs
- electrocardiogram (EKG), which records the electrical activity of the heart and can indicate volume overload of the right side of the heart
- echocardiogram (echo), which uses sound waves to produce a picture of the heart and to visualize blood flow through the heart chambers. This is often the primary tool used to diagnose ASD.
Treatment
Once an ASD is diagnosed, treatment will depend on the child's age and the size, location, and severity of the defect. In kids with very small ASDs, the defect may close on its own. Larger ASDs usually won't close, and must be treated medically. Most of these can be closed in a cardiac catheterization lab, although some ASDs will require open-heart surgery.
A child with a small defect that causes no symptoms may simply need to visit a pediatric cardiologist regularly to ensure that there are no problems; often, small defects will close spontaneously without any treatment during the first years of life. In general, a child with a small ASD won't require restrictions on his or her physical activity.
In most children with ASD, though, doctors must close the defect if it has not closed on its own by the time a child is old enough to start school.
Depending on the position of the defect, many children with ASD can have it corrected with a cardiac catheterization. In this procedure, a thin, flexible tube called a catheter is inserted into a blood vessel in the leg that leads to the heart. A cardiologist guides the tube into the heart to make measurements of blood flow, pressure, and oxygen levels in the heart chambers. A special implant can be positioned into the hole in the septum. The device is designed to flatten against the septum on both sides to close and permanently seal the ASD. In the beginning, the natural pressure in the heart holds the device in place. Over time, the normal tissue of the heart grows over the device and covers it entirely. This non-surgical technique for closing an ASD eliminates the scar on the chest needed for the surgical approach, and has a shorter recovery time, usually just an overnight stay in the hospital.
Because there is a small risk of blood clots forming on the closure device while new tissue heals over it, children who undergo device closure of an ASD may need to be on medications for several months after the procedure to prevent clots from forming.
If surgical repair for ASD is necessary, a child will undergo open-heart surgery. In this procedure, a surgeon makes a cut in the chest and a heart-lung machine is used to do the work of the circulation while the heart surgeon closes the hole. The ASD may be closed directly with stitches or by sewing a patch of surgical material over the defect. Eventually, the tissue of the heart heals over the patch or stitches, and by 6 months after the surgery, the hole will be completely covered with tissue.
For 6 months following catheterization or surgical closure of an ASD, antibiotics are recommended before routine dental work or surgical procedures to prevent infective endocarditis. Once the tissue of the heart has healed over the closed ASD most people who have had their ASDs corrected no longer need to worry about having a higher risk of infective endocarditis.
Your doctor will discuss other possible risks and complications with you prior to the procedure. Typically, after repair and adequate time for healing, children with ASD rarely experience further symptoms or disease.
Ventrical Septal DefectA ventricular septal defect (VSD) — sometimes referred to as a hole in the heart — is a type of congenital heart defect in which there is an abnormal opening in the dividing wall between the main pumping chambers of the heart (the ventricles). VSDs are the most common congenital heart defect, and in most cases they're diagnosed and treated successfully with few or no complications.
The right and left-sided pumping chambers (ventricles) are separated by shared wall, called the ventricular septum.
Kids with a VSD have an opening in this wall. As a result, when the heart beats, some of the blood in the left ventricle (which has been enriched by oxygen from the lungs) is able to flow through the hole in the septum into the right ventricle. In the right ventricle, this oxygen-rich blood mixes with the oxygen-poor blood and goes back to the lungs. The blood flowing through the hole creates an extra noise, which is known as a heart murmur. The heart murmur, can be heard when a doctor listens to the heart beat with a stethoscope.
Figure A shows the normal anatomy and blood flow of the interior of the heart. Figure B shows two common locations of ventricular septal defects. The defect allows oxygen-rich blood from the left ventricle to mix with oxygen-poor blood in the right ventricle.
VSDs can be located in different places on the ventricular septum, and they can be different sizes. The symptoms and medical treatment of the VSD will depend on those factors. In some rare cases, VSDs are part of more complex types of congenital heart disease.
What Causes a VSD?
Ventricular septal defects occur during fetal heart development and are present at birth. During the first weeks after conception, the heart develops from a large tube, dividing into sections that will eventually become the walls and chambers. If a problem occurs during this process, it can create a hole in the ventricular septum.
In some cases, the tendency to develop a VSD may be genetic. There can be genetic syndromes that cause extra or missing pieces of chromosomes that can be associated with VSD. For the vast majority of children with a defect, however, there's no clear cause of the VSD.
Signs and Symptoms of a VSD
VSDs are usually found in the first few weeks of life by a doctor during a routine checkup. The doctor will be able to detect a heart murmur, which is due to the sound of blood as it passes between the left and right ventricles. The murmur associated with a VSD has certain features that allow a doctor to distinguish it from heart murmurs due to other causes.
The size of the hole and its location within the heart will determine whether VSD causes any symptoms. Small VSDs will not typically cause any symptoms, and may ultimately close on their own. Older kids or teens who have small VSDs that persist usually don't experience any symptoms other than the heart murmur that doctors hear. They may need to see a doctor regularly to check on the heart defect and make sure it isn't causing any problems.
Moderate and large VSDs that haven't been treated in childhood may cause noticeable symptoms. Babies may have faster breathing and get tired out during attempts to feed. They may start sweating or crying with feeding, and may gain weight at a slower rate.
These signs generally indicate that the VSD will not close by itself, and cardiac surgery may be needed to close the hole. Surgery is typically done within the first 3 months of life to prevent it from causing other complications. A cardiologist can prescribe medication to lessen symptoms before surgery.
People with VSD are at greater risk in their lifetime of developing endocarditis, an infection of the inner surface of the heart. This occurs when bacteria in the bloodstream infect the lining of the heart. Bacteria are always in our mouths, and small amounts are introduced into the bloodstream when we chew and brush our teeth. The best way to protect the heart from endocarditis is to to reduce oral bacteria by brushing and flossing daily, and visiting the dentist regularly. In general, it is not recommended that patients with simple VSDs take antibiotics before dental visits, except for the first 6 months after surgery.
Diagnosing a VSD
If your child is discovered to have a heart murmur that was not noticed earlier, a doctor may refer you to a pediatric cardiologist, a doctor who specializes in diagnosing and treating childhood heart conditions.
In addition to doing a physical exam, the cardiologist take your child's medical history. If a VSD is suspected, the cardiologist may order one or more of the following tests:
- a chest X-ray, which produces a picture of the heart and surrounding organs
- an electrocardiogram, which records the electrical activity of the heart
- an echocardiogram (echo), which uses sound waves to produce a picture of the heart and to visualize blood flow through the heart chambers. This is often the primary tool used to diagnose VSD.
- a cardiac catheterization, which provides information about the heart structures as well as blood pressure and blood oxygen levels within the heart chambers. This test is usually performed for VSD only when additional information is needed that other tests cannot provide.
Treating a VSD
Once an VSD is diagnosed, treatment will depend on the child's age and the size, location, and severity of the defect. A child with a small defect that causes no symptoms may simply need to visit a cardiologist regularly to make sure that there are no other problems. In most children, a small defect will close on its own without surgery. Some may not close, but they do not get any larger. In cases where the VSD is small and has not closed, there are generally no restrictions to activities or to playing sports.
For kids with medium to large VSDs, surgery may be necessary. In most cases, this takes place within the first few weeks to months of life. In this procedure, the surgeon makes an incision in the chest wall, and a heart-lung machine is used to do the work of the circulation while the surgeon closes the hole. The surgeon can stitch the hole closed directly or, more commonly, sew a patch of manmade surgical material over it. Eventually, the tissue of the heart heals over the patch or stitches, and by 6 months after the surgery, the hole will be completely covered with tissue.
Certain types of VSDs may be closed during cardiac catheterization. A thin, flexible tube called a catheter is inserted into a blood vessel in the leg that leads to the heart. A cardiologist guides the tube into the heart to make measurements of blood flow, pressure, and oxygen levels in the heart chambers. A special implant, shaped into two disks formed of flexible wire mesh, can be positioned into the hole in the septum. The device is designed to flatten against the septum on both sides to close and permanently seal the VSD.
After healing from surgery or catheterization, kids with VSDs are considered cured and should have no further symptoms or problems.
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