Congenital Heart Defects

Congenital heart defects are abnormalities in the heart's structure that are present at birth. Approximately 8 out of every 1,000 newborns have congenital heart defects, ranging from mild to severe.

Congenital heart defects happen because of incomplete or abnormal development of the fetus' heart during the very early weeks of pregnancy. Some are known to be associated with genetic disorders, such as Down syndrome, but the cause of most congenital heart defects is unknown. While they can't be prevented, there are many treatments for the defects and any related health problems.

How a Healthy Heart Works

To understand more about congenital heart defects, it's helpful to understand how a healthy heart works.

The heart, lungs, and blood vessels make up the circulatory system of the human body. The heart is the central pump of the circulatory system, and consists of four chambers — the left atrium and left ventricle and the right atrium and right ventricle.

The heart also has four valves that direct the flow of blood through the heart:

1. The left atrium of the heart receives oxygen-rich blood from the lungs and then empties into the left ventricle through the mitral valve.
2. The left ventricle pumps oxygen-rich blood out to the rest of the body. Blood leaves the left ventricle through the aortic valve and enters the aorta, the largest artery (a blood vessel that carries oxygenated blood) in the body. Blood then flows from the aorta into the branches of many smaller arteries, providing the body's organs and tissues with the oxygen and nutrients they need.
3. After oxygen in the blood is released to the tissues, the now deoxygenated (oxygen-poor) blood returns to the heart through veins, the blood vessels that carry deoxygenated blood. This blood, which appears blue, enters the right atrium of the heart and then travels across the tricuspid valve into the right ventricle.
4. The right ventricle then pumps deoxygenated blood through the pulmonic valve into the lungs. The oxygen in the air we breathe binds to cells within this blood that is being pumped through the lungs. The oxygen-rich blood, which appears red, then returns to the left atrium and enters the left ventricle, where it is pumped out to the body once again.

This is the normal pathway that blood travels through the heart and the body. However, abnormalities in the heart's structure — such as congenital heart defects — can affect its ability to function properly.

Common Heart Defects

Common types of congenital heart defects, which can affect any part of the heart or its surrounding structures, include:

Aortic Stenosis

In aortic stenosis, the aortic valve is stiffened and has a narrowed opening (a condition called stenosis). It does not open properly, which increases strain on the heart because the left ventricle has to pump harder to send blood out to the body. Sometimes the aortic valve also does not close properly, causing it to leak, a condition called aortic regurgitation.

Atrial Septal Defect (ASD)

ASD is a hole in the wall (called the septum) that separates the left atrium and the right atrium.

Atrioventricular Canal Defect

This defect — also known as endocardial cushion defect or atrioventricular septal defect — is caused by a poorly formed central area of the heart. Typically there is a large hole between the upper chambers of the heart (the atria) and, often, an additional hole between the lower chambers of the heart (the ventricles). Instead of two separate valves allowing flow into the heart (tricuspid on the right and mitral valve on the left), there is one large common valve, which may be quite malformed. Atrioventricular canal defect is commonly seen in children with Down syndrome.

Coarctation of the Aorta (COA)

COA is a narrowing of a portion of the aorta, and often seriously decreases the blood flow from the heart out to the lower portion of the body.

Hypoplastic Left Heart Syndrome

When the structures of the left side of the heart (the left ventricle, the mitral valve, and the aortic valve) are underdeveloped, they're unable to pump blood adequately to the entire body. This condition is usually diagnosed within the first few days of life, at which point the baby may be critically ill.

Fortunately, many of these infants are recognized to have serious heart disease even before birth on ultrasound tests. A fetal echocardiogram is a specialized ultrasound that allows doctors to see the baby's heart in great detail and plan the best care for the baby while still in utero.

Patent Ductus Arteriosus (PDA)

The ductus arteriosus (DA) is a normal blood vessel in the developing fetus that diverts circulation away from the lungs and sends it directly to the body. (The lungs are not used while the unborn fetus is in amniotic fluid — the fetus gets oxygen directly from the mother's placenta.) The DA usually closes on its own shortly after birth; it is no longer needed once a newborn breathes on his own. If the DA doesn't close, then a condition called patent ductus arteriosus (PDA) results, which can result in too much blood flow to a newborn's lungs. PDA is common in premature babies.

Pulmonary Atresia

In this defect the pulmonic valve does not open at all and may indeed be completely absent. The main blood vessel that runs between the right ventricle and the lungs also may be malformed and the right ventricle can be abnormally small.

Pulmonary Stenosis

In pulmonary stenosis, the pulmonic valve is stiffened and has a narrowed opening (a condition called stenosis). It does not open properly, which increases strain on the right side of the heart because the right ventricle has to pump harder to send blood out to the lungs.

Tetralogy of Fallot (TOF)

Tetralogy of Fallot is actually a combination of four heart defects. It includes pulmonary stenosis, a thickened right ventricle (known as ventricular hypertrophy), a hole between the lower chambers (known as a ventricular septal defect), and an aorta that can receive blood from both the left and right ventricles, instead of draining just the left. Because deoxygenated (blue) blood can flow out to the body, children with this defect often appear bluish.

Total Anomalous Pulmonary Venous Connection

The pulmonary veins normally are the blood vessels that deliver oxygenated blood from the lungs to the left atrium. Sometimes these vessels don't join the left atrium during development. Instead they deliver blood to the heart by other pathways, which may be narrowed. Pressure builds up in this pathway and in the pulmonary veins, pushing fluid into the lungs, decreasing the amount of oxygenated blood that reaches the body. These infants often have difficulty breathing and appear bluish.

Transposition of the Great Arteries

In this condition, the pulmonary artery and the aorta (the major blood vessels leaving the heart) are switched so that the aorta arises from the right side of the heart and receives blue blood, which is sent right back out to the body without becoming oxygen-rich. The pulmonary artery arises from the left side of the heart, receives red blood and sends it back to the lungs again. The result is that babies with this condition often appear very blue and have low oxygen levels in the bloodstream. They usually come to medical attention within the first days of life.

Tricuspid Atresia

Blood normally flows from the right atrium to the right ventricle through the tricuspid valve. In tricuspid atresia, the valve is replaced by a plate or membrane that does not open. The right ventricle therefore does not receive blood normally and is often small.

Truncus Arteriosus

In an embryo, the aorta and the pulmonary artery are initially a single vessel. During normal development, that vessel splits to form the two major arteries. If that split does not occur, the child is born with a single common great blood vessel called the truncus arteriosus. There is usually a hole between the ventricles associated with this defect.

Ventricular Septal Defect (VSD)

One of the most common congenital heart defects, VSD is a hole in the wall (septum) between the heart's left and right ventricles. These can occur at different locations and vary in size from very small to very large. Some of the smaller defects may gradually close on their own.

Signs and Symptoms of Heart Defects

Because congenital defects often compromise the heart's ability to pump blood and to deliver oxygen to the tissues of the body, they often produce telltale signs such as:

• a bluish tinge or color (cyanosis) to the lips, tongue and/or nailbeds
• an increased rate of breathing or difficulty breathing
• poor appetite or difficulty feeding (which may be associated with color change)
• failure to thrive (failure to gain weight or weight loss)
• abnormal heart murmur
• sweating, especially during feedings
• diminished strength of the baby's pulse

If you notice any of these signs in your baby or child, call your doctor right away. If your doctor notices these signs, you may be referred to a pediatric cardiologist.

Diagnosing a Heart Defect

If a congenital defect is suspected, your doctor may refer you to a pediatric cardiologist. Some congenital heart defects cause serious symptoms right at birth, requiring newborn intensive care in the hospital and immediate evaluation by a cardiologist. Other defects, like small atrial septal defects, may go undiagnosed until the teen — or even adult — years.

After a complete physical examination, including evaluation of the baby's heart rate and blood pressure, the cardiologist probably will order a chest X-ray to evaluate the size and shape of the heart and to view the lungs.

An electrocardiogram (EKG) is usually done, too. EKGs are performed by placing small pads (called leads) on your child's chest, which are wired to a monitor that records and prints out the electrical signals of the heart.

The cardiologist will often order an echocardiogram, which provides detailed images of the heart by using ultrasound. Specialized ultrasound waves can demonstrate all of the heart chambers and valves, the great arteries arising from the heart, and the direction and speed of blood flow in various areas of the heart. Echocardiograms can also evaluate whether the heart is squeezing and relaxing normally. Echocardiograms are the primary tool for diagnosing congenital heart defects.

A fetal echocardiogram is a specialized type of ultrasound that allows diagnosis of heart problems in utero. This can be done as early as 16-18 weeks' gestation. These tests are usually ordered when an obstetrician suspects a heart abnormality on a level II ultrasound. They are also often ordered if there is another close family member with a congenital heart defect or when mom has a condition, such as diabetes, which may predispose a heart problem in the fetus.

Cardiac catheterization is sometimes performed as well. During this procedure, a long, thin tube called a catheter is threaded through blood vessels in the navel (in a newborn) or the groin and up into the heart. Once in place, the catheter can measure the oxygen levels and pressures within the heart's chambers. Dye may be injected through the catheter to better illustrate the heart's inner structures and determine the direction of blood flow through the heart. Nowadays, a number of congenital heart defects can be fixed in the cardiac catheterization laboratory. For instance, there are devices that can be used to close holes in the heart or to open up tight valves or narrowed blood vessels.

A pediatric cardiologist is the doctor most qualified to diagnose a congenital heart defect and provide treatment. This is true even before a baby is born. If you are an expectant parent and your baby has been diagnosed with a congenital heart defect via a fetal ultrasound, consult a pediatric cardiologist.

If You Suspect a Problem

If you think your child may have a congenital heart defect or you notice any signs (such as difficulty breathing or feeding, or bluish skin) that concern you, call your doctor. In more urgent cases, such as if your baby suddenly turns blue or stops breathing, call 911.

Today there are more treatment options for congenital heart defects than ever before, and most defects are treated successfully. If you suspect that your child has a heart defect, the sooner you get medical attention, the better chance your child will have of making the fullest recovery possible.

With all the medical resources available, a congenital heart defect does not necessarily mean a child cannot lead a normal life. Working with your doctor, you'll get the best care for your child.

Read More

Coarctation of the Aorta

The aorta is the major blood vessel that carries blood away from the heart to the body. When someone has coarctation of the aorta, the aorta is narrowed at some point.

Here's how a healthy heart and aorta work: Blood that needs oxygen comes from all over the body and enters the right side of the heart, which pumps it to the lungs. The lungs fill the blood with oxygen, and this oxygen-rich blood returns from the lungs to the left side of the heart. The left side of the heart finishes up by pumping the blood out through the aorta. From the aorta, the blood travels through arteries that reach all of the body's organs and tissues, bringing them oxygen. Then the blood returns to the heart through veins and begins the cycle once again.

When part of the aorta is narrowed, called a coarctation, that defect can affect the body's blood circulation because the left side of the heart has to work harder to pump blood through the narrowed aorta. Sometimes the narrowing is minor and may not even cause symptoms. In other cases the aorta may be more constricted, placing a strain on the heart's left ventricle (the chamber that pumps blood to the aorta and out to the body). A coarctation can occur anywhere in the aorta, but it is most often found after the point where the arteries that carry blood to the upper body and head branch off from the aorta.

What Causes Coarctation of the Aorta?

Coarctation of the aorta (or COA for short) is a congenital defect, meaning that someone is born with it. About 1 in 100 children is born with a heart problem, and coarctation represents about 8% of cases. Doctors don't know for sure why certain people are born with this narrowing of the aorta.

Coarctation occurs more commonly in boys. However, it is commonly seen in girls with Turner syndrome, in which one of a girl's two X chromosomes is incomplete or missing. COA may occur with other birth defects or congenital heart conditions, such as a ventricular septal defect (a hole in the wall between the heart's left and right ventricles).

Coarctation can also be associated with abnormalities of the other structures of the left side of the heart. A common association is a bicuspid aortic valve, in which the aortic valve between the left ventricle and aorta has two leaflets instead of the normal three.

Most people with COA are diagnosed when they are babies or young children. But some may not be diagnosed until they are teens or even adults. Usually, in this case, the narrowing in the aorta is not severe enough to cause serious symptoms while the person is very young. But even those who do not have major symptoms usually need to be treated because the coarctation can eventually cause problems. COA will not go away on its own.

Signs and Symptoms

Often an abnormal blood pressure test is the first sign of COA detected by a doctor. During a physical exam, the doctor may find that a child with a coarctation has a higher blood pressure in the arms than in the legs. The doctor may also hear a heart murmur or notice that the pulse in the groin is weak or difficult to feel. Any person diagnosed with high blood pressure should be checked for coarctation of the aorta.

Kids who have COA often do not have any symptoms and have only mild signs that are discovered by accident during a regular visit to the doctor. A child who does have symptoms may experience some or all of these:

• cold legs and feet
• shortness of breath, especially when exercising
• chest pain

Diagnosis and Treatment

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 disease in kids and teens. The cardiologist will listen to the heart, feel the pulses, and check blood pressure. The doctor will probably order an echocardiogram, a test that uses sound waves to create a picture of the heart and its circulation. Other tests that produce images of the heart, such as a chest X-ray, a magnetic resonance imaging (MRI) test, or a computerized tomography (CT) scan, may also be used to help the cardiologist look for a narrowing of the aorta.

A severe coarctation is usually diagnosed shortly after birth and repaired by surgery immediately. In an older patient, doctors often recommend that COA be treated quickly, since it can cause persistent high blood pressure and cause heart enlargement. The defect can also cause dissection or rupture of the aorta, which can be fatal in many people by the age of 40.

Coarctation of the aorta can be repaired either by surgery or other procedures. Different types of surgery can repair a narrowing of the aorta, but one of the most common ways to fix COA is to remove the narrow section and reconnect the two ends of the aorta.

In some cases, doctors may choose to do a procedure known as balloon dilation or balloon angioplasty. They insert a tiny balloon into a blood vessel in the leg and use a very thin wire to thread it up to the aorta, across the narrow area. When the doctor inflates the balloon, the narrow area is expanded. After the area has been widened, the balloon is removed. The cardiologist may also implant a device called a stent to keep the area open after the procedure.

Home Care

Once the defect has been fixed, most symptoms of COA disappear right away because the blockage that caused those symptoms is now gone. Some people will still have high blood pressure for a while and may 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 their bodies enough time to heal. Someone whose blood pressure remains high may have to continue to limit certain activities as long as the blood pressure remains high.

Kids who've had a COA corrected will still need to be monitored over time. In some, the narrowing of the aorta can return after surgery or balloon dilation treatment. Regular visits to a cardiologist — often every year or two after recovery — 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 he or she has shortness of breath, chest pain, or fainting. Overall, kids who have had coarctation of the aorta can expect to continue leading a normal life after their treatment.

Read More

Atrial Septal Defect

An atrial septal defect (ASD) — 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 upper filling chambers of the heart (the atria). In most cases ASDs are diagnosed and treated successfully with few or no complications.

What Is an Atrial Septal Defect?

To understand this defect, it first helps to review some basics about the way a healthy heart typically works.

The heart has four chambers: The two lower pumping chambers are called the ventricles, and the two upper filling chambers are the atria.

In a healthy heart, blood that returns from the body to the right-sided filling chamber (right atrium) is low in oxygen. This blood passes to the right-sided pumping chamber (right ventricle), and then to the lungs to receive oxygen. The blood that has been enriched with oxygen returns to the left atrium, and then to the left ventricle. It's then pumped out to the body through the aorta, a large blood vessel that carries the blood to the smaller blood vessels in the body. The right and left filling chambers are separated by a thin shared wall, called the atrial septum.

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.

What Causes an ASD?

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 of an ASD

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.

Diagnosing an ASD

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.

Treating an ASD

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.

Caring for a Child With an ASD

Kids who undergo cardiac catheterization to close an ASD usually spend the night in the hospital after the procedure. Those who have had a catheterization procedure should also be kept out of gym class or sports practice for a week; after a week, they can usually return to their normal physical activities, with their doctor's OK.

Kids who undergo surgery for their ASDs usually go home after a few days in the hospital if there are no complications. After surgical ASD repair, the main medical concern is the healing of the chest incision. In general, the younger patients are when they have their surgical repairs, the less pain they will have during recovery. The child will be watched closely for signs or symptoms that may indicate a problem. If your child has trouble breathing, is not eating, has fever, or redness or pus oozing from the incision, get medical treatment right away. In most cases, kids who have had ASD surgery recover quickly and without problems.

In the weeks following surgery or cardiac catheterization, your doctor will check on your child's progress. Your child may undergo another echocardiogram to make sure that the heart defect has closed completely. Kids who have undergone ASD repair will continue to have follow-up visits with the cardiologist.

Most children who undergo treatment for ASDs recover quickly — you may even notice that within a few weeks of treatment, your child is eating more and is more active than before surgery. However, some signs and symptoms may indicate a problem. If your child is having trouble breathing, call the doctor or take your child to the emergency department immediately. Other symptoms that may indicate a problem include:

• a bluish tinge or color (cyanosis) to the skin around the mouth or on the lips and tongue
• poor appetite or difficulty feeding
• failure to gain weight or weight loss
• listlessness or decreased activity level
• prolonged or unexplained fever
• increasing pain, tenderness, or pus oozing from the incision

Call your doctor if you notice any of these signs in your child after closure of the ASD.

Any time a child is diagnosed with a heart condition, it can be scary. But the good news is that your pediatric cardiologist will be very familiar with this condition and how to best manage it. Most kids who've had an ASD corrected have a normal life expectancy and go on to live healthy, active lives.

Read More

Arrhythmias

An arrhythmia is an abnormal heart rhythm usually caused by an electrical "short circuit" in the heart. The heart normally beats in a consistent pattern, but an arrhythmia can make it beat too slowly, too quickly, or irregularly. This can cause the heart muscle's pumping function to work erratically, which can lead to a variety of symptoms, including fatigue, dizziness, and chest pain.

What Causes Arrhythmias?

The heart has its own conduction system, or electrical system, that sends electrical signals around the heart, telling it when to contract and pump blood throughout the body. The electrical signals originate from a group of cells in the right atrium, called the sinus node. The sinus node functions as the heart's pacemaker and makes sure the heart is beating at a normal and consistent rate. The sinus node normally increases the heart rate in response to factors like exercise, emotions, and hormones, and slows the heart rate during sleep.

However, sometimes the electrical signals flowing through the heart don't "communicate" properly with the heart muscle, and the heart can start beating in an abnormal pattern — an arrhythmia.

Arrhythmias can be temporary or permanent. They can be caused by several things, but can also occur for no apparent reason. Arrhythmias can be congenital, meaning a child is born with the condition. This can happen in a child with a birth defect of the heart, or even if a child's heart has formed normally.

Other causes of arrhythmias in kids include chemical imbalances in the blood, infections, or other diseases that cause irritation or inflammation of the heart, medications (prescription or over-the-counter), and injuries to the heart from chest trauma or heart surgery. Other factors such as illegal drugs, alcohol, tobacco, caffeine, stress, and some herbal remedies also can cause arrhythmias.

Signs and Symptoms

Because arrhythmias can cause the heart to beat less effectively, blood flow to the brain and to the rest of the body can be interrupted. If the heart is beating too fast, its chambers can't fill with the proper amount of blood. If it's beating too slowly or irregularly, the proper amount of blood can't be pumped out to the body. If the body doesn't get the supply of blood it needs to run smoothly, these symptoms can occur:

• dizziness
• fatigue
• lightheadedness
• weakness
• palpitations (a feeling of fluttering or pounding in the chest)
• shortness of breath
• chest pain
• fainting

Arrhythmias can be consistent or come and go at random. Sometimes arrhythmias can cause no detectable symptoms at all. In these cases, the arrhythmia can only be discovered during a physical examination or a heart function test.

What's a Normal Heart Rate?

Heart rate is measured by counting the number of beats per minute. Normal heart rate varies depending on factors like age and whether the person leads an active lifestyle or not (for example, trained athletes such as a teen or adult who plays competitive sports often have a lower resting heart rate).

The normal range for resting heart rate decreases from infancy to adulthood. An infant's normal resting heart rate from age 0–3 months is usually between 100 to 150 beats per minute. A child between the ages of 1–3 years typically has a resting heart rate of 70 to 110 beats per minute, and by 12 years of age will have a normal resting heart rate between 55 to 85 beats per minute.

An abnormally fast heart rate is call tachycardia. An abnormally slow rate is called bradycardia. Your doctor should help you determine whether or not your child's heart rate is abnormally fast or slow, since the significance of an abnormal heart rate depends on the situation. For example, an older child or adult with bradycardia might begin to show symptoms when his or her heart rate drops below 50 beats per minute. However, trained athletes have a lower resting heart rate — so bradycardia in these individuals isn't considered abnormal if no symptoms are associated with it.

Types of Arrhythmias

Types of arrhythmias include:

Premature Atrial Contraction (PAC) and Premature Ventricular Contraction (PVC)

PVCs are usually considered minor arrhythmias, in which someone may feel a fluttering or pounding in the chest caused by an early or extra beat. PACs and PVCs are very common, and are what happens when it feels like your heart "skips" a beat. It doesn't skip a beat — an extra beat actually comes sooner than normal. Occasional premature beats are common and considered normal, but in some cases they can indicate an underlying medical problem or heart condition.

Tachycardias

Tachycardias are arrhythmias that involve abnormally rapid heartbeat. They fall into two major categories — supraventricular and ventricular:

• Supraventricular Tachycardia (SVT). Supraventricular tachycardia (SVT) is the most common significant arrhythmia in children. It's characterized by bursts of fast heartbeats that originate in the atria (upper chambers of the heart) or the heart cells that carry electrical signals from the atria to the ventricles (lower chambers of the heart). The bursts can happen suddenly, and episodes can last anywhere from a few seconds to several days. Specific treatment is usually recommended if incidents of SVT are long-lasting or frequent.
• Wolff-Parkinson-White (WPW) Syndrome. Wolff-Parkinson-White (WPW) syndrome, a type of SVT, can run in families and is characterized by an extra electrical conduction path that connects the upper and lower chambers of the heart. The presence of this extra pathway can cause the heart to become flooded with electrical impulses, speeding up the heart rate.
• Ventricular Tachycardia. Ventricular tachycardia is a serious but relatively uncommon condition in children. It originates in the lower chambers of the heart and is usually a sign of serious underlying heart disease.

Bradycardias

The following are examples of bradycardias — arrhythmias characterized by abnormally slow heartbeat:

• Sick Sinus Syndrome. Sick sinus syndrome happens when the heart's sinus node or another part of its electrical conduction system isn't working correctly. This most commonly occurs in kids after surgery to correct a congenital heart defect. Abnormally slow heartbeat is typically seen in this condition; however, episodes of rapid heartbeat due to SVT can also occur.
• Heart Block. Heart block is often caused by a congenital heart defect, although it can also result from disease or injury. Heart block happens when electrical impulses can't make their way from the upper to lower chambers of the heart. When this happens, another node in the lower chambers takes over and acts as the heart's pacemaker. Although it sends out electrical impulses to keep the heart beating, the transmission of the signals is much slower, leading to a slower heart rate.

How Are Arrhythmias Diagnosed?

Doctors use several tools to diagnose arrhythmias. It's very important to know your child's medical history and give this information to your doctor, who will use it, along with a physical examination, to begin the evaluation.

If an arrhythmia is suspected, the doctor will probably recommend an electrocardiogram (EKG) to measures the heart's electrical activity. There is nothing painful about an EKG — a series of electrodes (small metal tabs) are fixed to the skin with sticky papers, and the information obtained about the electrical activity of your child's heart is transferred to a computer, where it's then interpreted and drawn as a graph.

The doctor might recommend the following types of EKG tests:

• Resting EKG. This measures resting heart rate and rhythm, and lasts about a minute.
• Exercise EKG (also called a stress test). This measures heart rate and rhythm while exercising, like riding a stationary bicycle or walking on a treadmill.
• Signal-average EKG. This measures heart rate much like a resting EKG. The only difference is the signal-average EKG monitors the heartbeat over a longer time period (around 15 to 20 minutes).
• Holter monitor. This is an EKG done over a very long period of time, usually 24 hours or more. The electrodes are connected to the chest, and the wires are attached to a portable EKG recorder. The child is encouraged to continue normal daily activities, but must be careful to not get the electrodes wet (for example, no swimming, showering, or activities that cause a lot of sweating). There are two kinds of Holter monitoring: continuous recording, which means the EKG is on throughout the entire monitoring period; and event monitoring, which means data are recorded only when the child feels symptoms and then turns the Holter monitor on.

How Are Arrhythmias Treated?

Your child may have an arrhythmia but may feel no symptoms at all. Many arrhythmias don't require treatment; however, some can pose a health problem and need to be evaluated and treated by a doctor.

Depending on the type and severity of the arrhythmia, one of the following options might be recommended by your doctor:

• Medications. Many types of prescription anti-arrhythmic medications are available to treat arrhythmia. Your child’s doctor will determine which is best by considering the type of arrhythmia, possible underlying medical causes, and any medications your child is taking. Sometimes, anti-arrhythmic medications can increase symptoms and cause unwanted side effects, so their use and effectiveness should be closely monitored by the doctor, you, and your child.
• Pacemakers. A pacemaker is a small, battery-operated device implanted into the body (near the collarbone) through a surgical procedure. Connected to the heart by a wire, pacemakers can help treat bradycardia. Through a sensing device, a pacemaker can detect if a child’s heart rate is too slow and sends electrical signals to the heart to speed up the heartbeat.
• Defibrillators. Like a pacemaker, a defibrillator can deliver electrical impulses to the heart. A small battery-operated implantable cardioverter defibrillator (ICD) can be implanted into the body (near the left collarbone) through a surgical procedure. Wires run from the defibrillator to the heart. It senses if the heart has developed a dangerously fast or irregular rhythm and delivers an electrical shock to restore a normal heartbeat.
• Catheter ablation. "Ablation" literally means removal or elimination. In the case of catheter ablation, a catheter (a long, thin tube) is guided through a vein in the arm or leg and inserted into the heart to eliminate the heart muscle cells that are triggering the arrhythmia. Once the problem area of the heart is pinpointed, the catheter sends waves of high-frequency radio waves into the muscle cells and destroys them.
• Surgery. Surgery is usually the treatment recommended only if all other options have failed. In this case, the child is put under anesthesia, the chest is opened, and the heart is exposed. Then, the tissue causing the arrhythmia is removed.

When to Call the Doctor

Although many arrhythmias are minor and don't represent a significant threat to your child's health, some can indicate a more serious health problem. If your child has been having symptoms like those listed above, call your doctor.

Read More