What Is Congenital Heart Disease (Congenital Heart Defect)?

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Main Category: Heart Disease
Also Included In: Cardiovascular / Cardiology;  Genetics;  Pediatrics / Children's Health
Article Date: 03 Mar 2010 - 0:00 PST

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Congenital heart disease, also known as congenital heart defect, is a general term for a series of faults in the structure of the heart and great vessels that is present from birth. In the majority of cases, the defect either obstructs blood flow in the heart or nearby vessels, or causes blood to flow through the heart in an abnormal way. Congenital heart defect is a common birth defect, and a leading cause of deaths linked to birth defects.

Congenital heart disease is far more treatable today than it used to be. A significant number of babies who once died of congenital heart defect today survive well into adulthood, thanks to advances in surgical treatment. Approximately 85% of newborns today with congenital heart defect survive well into adulthood.

Even so, many adults who were initially treated for congenital heart disease may not be receiving adequate follow-up care. Adults who were treated as infants should check with their doctor. Patients may have complex health needs and might require life-long specialized care.

According to the National Health Service (NHS), UK, there are over 30 different types of heart defect. The two main types of congenital heart defect are:

• Cyanotic heart disease - the heart defect results in low blood oxygen levels. Babies suffer from breathlessness, fainting and fatigue. They typically have blue-colored toes, fingers and lips.
• Acyanotic heart disease - blood oxygen levels are adequate, but the blood is not pumped around the body in a normal way. Symptoms may not be immediately apparent in newborns. The condition can cause problems over time. Blood pressure is higher than normal, making the heart work harder in order to pump blood, often weakening the heart. The patient may suffer from pulmonary hypertension (high blood pressure in the arteries in the lungs), causing breathlessness, fatigue, dizziness and fainting.

Approximately 6 in every 1,000 babies are born with some kind of congenital heart disease. Half of these babies will require surgery immediately after they are born, while the rest will likely need surgery at some time during the childhood.

Certain genetic conditions, such as Down's syndrome, may raise the risk of congenital heart disease, as can an infection during pregnancy, such as rubella (German measles). In a significant proportion of cases no clear cause is ever found.

What are the signs and symptoms of congenital heart disease?

A symptom is something the patient senses and describes, while a sign is something other people, such as the doctor notice. For example, sleepiness may be a symptom while dilated pupils may be a sign.

Signs and symptoms of cyanotic heart disease:

• Breathing difficulties. A child may squat in an attempt to breathe properly
• Chest pains
• Cyanosis - the lips, fingers and toes are bluish
• Delayed growth
• Feeding difficulties, poor appetite
• Hypoxia - low concentrations of oxygen in the body, during which the child may start hyperventilating
• Sweating - especially when the baby is feeding
• Syncope (fainting)
• The child is typically underweight and small for his/her age

Signs and symptoms of acyanotic heart disease:

• Breathlessness - especially during exertion
• Chest pain
• Delayed growth
• Extreme fatigue
• Feeding difficulties, poor appetite
• Sweating - especially when the baby is feeding
• The child is typically underweight

Congenital heart disease signs and symptoms later in life - these may recur many years after the patient had treatment for a heart defect.

• Arrhythmias - abnormal heart rhythms
• Breathlessness
• Cyanosis
• Dizziness
• Edema - swelling of organs or body tissues
• Fatigue
• Syncope (fainting)
• The patient becomes easily tired after exertion

What are the risk factors for congenital heart disease?

A risk factor is something which increases the likelihood of developing a condition or disease. For example, obesity significantly raises the risk of developing diabetes type 2. Therefore, obesity is a risk factor for diabetes type 2.

Congenital heart disease is usually the result of a problem early on during the baby's development inside the womb. Some genetic and environmental risk factors may also contribute to the development of the condition, including:

• Rubella - also known as German measles, is an infectious disease caused by the rubella virus. The virus passes from person-to-person via droplets in the air expelled when infected people cough or sneeze - the virus may also be present in the urine, feces and on the skin. The hallmark symptoms of rubella are an elevated body temperature and a pink rash. If a pregnant woman becomes infected with Rubella there is a serious risk of birth defects in the unborn baby. If the pregnant mother is infected within the first 20 weeks of pregnancy the child may be born with congenital rubella syndrome, which consists of a range of serious incurable illnesses, including congenital heart disease. Spontaneous abortion (miscarriage) occurs in up to one-fifth of pregnant women who become infected.
• Diabetes Types I or II - if the mother had diabetes the development of the baby inside the womb may have been affected. Gestational diabetes is not linked to an increase in congenital heart defects for the baby.
• Medications - some medications taken during pregnancy may raise the risk of congenital heart defects for the baby. Examples include isotretinoin (Accutane) for the treatment of acne, and lithium (Eskalith) for the treatment of bipolar disorder.
• Alcohol consumption/abuse during pregnancy - women who consume alcohol during pregnancy may raise the risk of congenital heart defects for the baby.
• Genetics - over 30% of children with Down syndrome have heart defects. A deletion of genetic material on chromosome 22 may case congenital heart defects - genetic tests are available for this. Experts say that in many cases congenital heart defects run in families. Turner syndrome and Noonan syndrome are both linked to congenital heart disease risk.

What are the causes of congenital heart disease?

The heart is a pump which consists of four chambers:

• The left atrium
• The left ventricle
• The right atrium
• The right ventricle

..and four valves; they control bloodflow through the heart and around the body:

• The mitral valve
• The aortic valve
• The tricuspid valve
• The pulmonary valve

The heart, along with the lungs supplies oxygen-rich blood to cells and tissues throughout the body. When blood is pumped into the lungs it collects oxygen, which is then transported to cells and tissues. Cells and tissues remove blood oxygen. The blood, which is now low in oxygen travels back to the heart and is then pumped into the lungs, etc. When there is a congenital heart disease there is something wrong with the structure of the heart, and the cycle does not work properly. Types of acyanotic heart disease

• Ventricular septal defect (VSD) - the most common cause of acyanotic heart disease. There is a hole between the left and right ventricle. Blood pressure is higher on the left side of the heart than the right. If there is a hole, blood is pushed out of the left ventricle into the right ventricle. This means that the heart has to work extra to empty out the right ventricle - this puts a strain on the heart. The higher blood level can also cause pulmonary hypertension (high pressure in the lungs). This can result in lung damage.
• Atrial septal defect (ASD) - there is a hole between the left and right atriums. Similarly, the heart is under greater strain and there is potential lung damage.
• Pulmonary stenosis - the pulmonary valve is abnormally narrow, consequently the heart is under greater strain to pump blood into the lungs.
• Aortic stenosis - the aortic valve is abnormally narrow. The heart has to pump harder to get blood through the valve. This puts extra strain on the heart. Blood that goes through the aortic valve is crucial for the oxygen supply of many parts of the body. Patients with aortic stenosis may experience dizziness and breathlessness.
• Patent ductus ateriosus (PDA) - this heart passage (duct) is supposed to close shortly after the baby is born when he/she begins to breathe normally. In a baby with PDA the duct does not close properly. Blood that is supposed to be pumped away from the lungs leaks back into the pulmonary valve and into the lungs. The heart and lungs have to work extra hard to make up for this problem.

Types of cyanotic heart disease

• Tetralogy of Fallot (TOF) - the leading cause of cyanotic heart disease. It is a combination of four different heart defects:
  
  
  • Displaced aorta - the aortic valve is in the wrong place
  • Pulmonary stenosis - the pulmonary valve is abnormally narrow
  • Right ventricular hypertrophy - the muscles of the right ventricle are too thick
  • Ventricular septal defect - there is a hole between the left and right ventricle
  Oxygen-rich and oxygen-low blood get mixed up, resulting in poor oxygen supply to body organs and tissues. The child will typically be breathless and have blue skin.
• Transposition of the great arteries (TGA) - the second most common cause of cyanotic heart disease. The aortic and pulmonary valves are connected to the each others' corresponding arteries. Instead of pumping low-oxygen blood to the lungs, it is pumped into the body, causing cyanotic heart disease.

Congenital heart diseases may resurface during adulthood

Some people may find that their congenital heart defects show symptoms during adulthood, even if the problems were treated during childhood. Experts say that heart defects are repaired so that heart function improves; but they are rarely cured. Even after treatment things may not be completely normal.

Even if treatment was successful during childhood, there is still a risk it may re-emerge later on in life. Sometimes, signs and symptoms during childhood may not have been serious enough to warrant repair - but they have worsened over time and need treatment later on.

One of the possible complications of a childhood surgery may not have emerged at the time, but does so during adulthood. For example, treatment may have left scar tissue behind in the heart, raising the risk of arrhythmia (abnormal heart rhythm).

Diagnosing congenital heart disease

Diagnosing before the baby is born (antenatal diagnosis) - a fetal echocardiography can be used to determine whether the developing fetus has congenital heart disease. The device is a kind of ultrasound scanner, specifically designed to create a picture of the insides of the chambers of the developing baby's heart. Typically, the test is done during the 18th to 20th week of pregnancy. This test may not detect mild cases.

Diagnosing after the baby is born (postnatal diagnosis) - if the newborn baby has the hallmark signs of cyanotic heart disease - bluish coloring of the skin - diagnosis is usually made rapidly. Diagnosis of acyanotic heart disease often takes longer, in some cases not until the child is three years old. If the baby has problems feeding, is growing more slowly than expected, has shortness of breath after exertion, is tired after exertion, or has swelling of the hands, feet and ankles the doctor should be told immediately.

• Echocardiogram - this ultrasound scan allows the doctor to see the heart muscles and valves.
• Electrocardiogram (ECG) - this device records the patient's heart's activity. A technician placed probes on the skin of the chest which reveal the patterns of electric impulses through the heart as wave patterns. This test can assess how well the heart beats.
• Chest X-ray - the aim here is to look at the size of the heart (is it too big), and whether there is too much blood in the lungs.
• Pulse oximetry - this device measures oxygen saturation of arterial blood. A special sensor is placed on the patient's fingertip, ear or toe.
• Cardiac catheterization - this test can determine how blood is pumping through the patient's heart. A catheter (a thin flexible tube) is passed into the right or left side of the heart, usually from the groin or the arm. The doctor is guided by X-rays or an MRI scanner. Once it is in place, the doctor may:
  
  
  • Collect blood samples
  • Examine the heart arteries with a technique called fluoroscopy
  • Measure oxygen levels in various parts of the heart
  • Measure pressure and blood flow in heart's chambers and also in the large arteries around the heart
  • Take a small sample of heart muscle (biopsy)
  The patient receives a local anesthetic.

Diagnosing adults with congenital heart disease - the doctor will perform a physical exam, and ask the patient questions about his/her medical and family history. If the doctor hears an abnormal heartbeat, it could be a sign of some lingering heart defect. The following diagnostic tests may be ordered:

• Cardiac catheterization
• Cardiac MRI (magnetic resonance imaging) scan - this imaging technique uses a magnetic field and radio waves to create images of the heart. The patient lies on a table inside a long doughnut/tube like machine that produces a magnetic field.
• Chest X-ray
• Echocardiogram
• Electrocardiogram (ECG)
• Exercise stress test - the patient exercises on a treadmill (running machine with a conveyor belt) to a standardized protocol. The speed and elevation are progressively increased, typically changing at three-minute intervals. The patient's EKG (electrocardiogram), heart rate (pulse rate), heart rhythm and blood pressure are monitored throughout the whole procedure.

What are the treatment options for congenital heart disease?

Sometimes congenital heart disease improves without treatment being required, or the defect may be so small that treatment is not needed. However, in the majority of cases the condition is serious and requires surgery and/or medications.

• Catheters - this is a long, flexible tube that is inserted into the heart. Surgical tools are passed down through the catheter to repair heart defects. This type of surgery is non-invasive - the child will have no major surgical incisions in the chest.
• Open heart surgery - in more serious cases the surgeon may have to operate directly on the heart. An incision is made on the child's chest so that damaged/defective parts of the heart can be repaired. The heart will be stopped and a machine pumps blood around the body during the operation.
• Heart transplant - in very severe cases the damaged heart may need to be replaced for the patient to survive. The healthy heart of a child who has recently died replaces the surviving child's defective heart. Consent is needed from the deceased child's family.
• Septal defects - if the child has a VSD (ventricular septal defect) or ASD (atrial septal defect), recommended treatment will depend on how serious the defect is. In mild cases the doctor may recommend watchful waiting - the child is monitored, but no treatment is given. Experts say that in the majority of mild cases the defect corrects itself in time.
  
  In mild to medium-sized defects a catheter may be used to seal the defect with a specially designed mesh.
  
  In more serious cases the doctor will probably have to perform open heart surgery. A patch will be stitched over the defect.
• Stenosis (narrowing of the aorta or pulmonary valve) - treatment options here depend the severity of the stenosis. In mild cases the doctor will probably recommend a policy of watchful waiting. The child may also be given an antihypertensive medication (a drug to lower blood pressure).
  
  In a more serious case the doctor may perform a balloon angioplasty. A small balloon is passed through the catheter, when in position it is inflated, resulting in a widening of the targeted valve. The balloon is then removed. In some cases a stent (a metal coil) is used to stop the valve from narrowing again.
  
  In very serious cases the surgeon may have to replace the faulty valve. This will require open heart surgery. Replacement valves may be artificially made, taken from pigs and modified for human use, or obtained from human donors.
  
  The surgeon may use a relatively new technique using a catheter to replace the aortic valve (catheter insertion of a new aortic valve). There is not yet enough evidence to evaluate the long-term safety or effectiveness of this technique (March 2010).
• Patent ductus ateriosus (PDA) - the patient will usually be given medication soon after birth. Examples include ibuprofen or indomethacin, to stimulate the closure of the duct causing PDA. If this does not work the surgeon may use a catheter to seal the duct with a plug or metal coil.
• Tetralogy of Fallot (TOF) - babies with severe symptoms of breathlessness may require emergency surgery. A procedure called a BT (Blalock-Taussig) shunt is used. An artery is shunted (diverted) into the lungs so that blood can be enriched with oxygen before continuing on to the rest of the body. Later on, when the baby is older, open heart surgery will be performed where the defect between the ventricles is sealed and the pulmonary valve is repaired.
• Transposition of the great arteries (TGA) - this is done soon after the birth of the baby. It requires open heart surgery, using a technique called an arterial switch. The arteries are cut and reattached to their correct positions on the other side of the heart (to the pulmonary and aortic valves).

Congenital heart disease treatment for adults - as with babies and children, treatment options for adults vary, and depend on several factors, including the severity of the disease. The doctor may recommend treatment to correct the heart defect, or therapy to treat the complications caused by the defect.

• Watchful waiting (regular checkups) - if defects are relatively minor, there may only be periodic checkups to determine whether the patient's condition has worsened.
• Medications - in some mild cases medications may be administered to help the heart work better (and no other treatment).
• Catheters - as in the case with babies and children, catheterization techniques may be used to repair some congenital heart defects, without the need for open heart surgery.
• Open heart surgery - in more complicated or serious cases the doctor may have to perform open heart surgery. These are major medical procedures and recovery times can be lengthy.
• Heart transplant - if the defect cannot be repaired the patient may need a new heart.

It is wrong to believe that treatment during childhood means that the problem has gone away and no further follow-up is required - this is rarely the case. Treatment for congenital heart disease does not cure it. Patients are at increased risk of developing complications throughout their lives. Some may require further surgery later on in life.

Adults who have had congenital heart disease treatment as children should liaise with their doctor about follow-up care, which should be carried out periodically for the rest of their lives. Checkups should ideally be done with cardiologists who are trained in monitoring adults with congenital heart diseases. It may not always be easy to find one.

Pregnancy - a woman with a congenital heart disease should talk to her doctor before planning to become pregnant. Although the majority of patients have normal pregnancies, it is important to discuss the risks, as well as any special care that may be required during pregnancy. Couples trying to have children who have congenital heart disease may benefit from genetic counseling, where they may learn about the risks of passing on the disease to their offspring.

What are the possible complications of congenital heart disease?

Some complications do not develop until many years after treatment.

Developmental milestones - certain milestones, such as walking or talking may take longer to reach for children with congenital heart disease. There may also be learning difficulties. Some children will benefit from specialized help. In the UK local authorities will draw up an IEP (individual education plan) for the child, which may include speech, language, psychological and educational help.

Endocarditis - the endocardium is the innermost tunic of the heart, including the endothelium and subendothelial connective tissue; in the atrial wall, smooth muscle and numerous elastic fibers also occur. Endocarditis is inflammation of the endocardium. In other words, it is the inflammation of the heart lining, heart muscles and heart valves. It is commonly caused by a staphylococcal infection - usually an infection in another part of the body, such as on the skin or the gums that travels through the blood and reaches the heart. Patients with congenital heart disease are advised to keep their gums clean and avoid piercings of the skin (tattoos and body piercings).

Patients with congenital heart disease have a higher risk of developing endocarditis, compared to other people.

Endocarditis is very difficult to diagnose, and often doctors may take a long time to get the correct diagnosis. Symptoms may be more or less severe depending on the type of bacteria or fungi causing the infection. Patients with underlying heart problems tend to have more severe symptoms.

Signs and symptoms of endocarditis, many of which are not specific to the disease, may include:

• A high temperature (fever)
• A new heart murmur
• Aching muscles (sometimes quite painful)
• Alterations in heart murmur
• Bleeding under fingernails or toenails
• Broken blood vessels in the eyes
• Broken blood vessels in the skin
• Chest pains
• Coughing
• Headache
• Shortness of breath (panting)
• Small lumps (nodules) on fingers and/or toes
• Sweating (this may include night sweats)
• Swelling of abdomen
• Swelling of limbs
• Tiredness (fatigue)
• Unexpected weight loss
• Weakness

The majority of patients with endocarditis will receive a course of antibiotics. These will be administered through a drip (intravenously), so hospitalization is required.

Arrhythmias - irregular heartbeats - the heart may beat too fast (tachycardia), too slowly (bradycardia), too early (premature contraction) or too irregularly (fibrillation). Arrhythmias are heart-rhythm problems - they occur when the electrical impulses to the heart that coordinate heartbeats are not working properly, making the heart beat too fast/slow or inconsistently.

Stroke - a condition where a blood clot or ruptured artery or blood vessel interrupts blood flow to an area of the brain. A lack of oxygen and glucose (sugar) flowing to the brain leads to the death of brain cells and brain damage, often resulting in an impairment in speech, movement, and memory.

Heart failure - the heart is not pumping blood around the body efficiently. The patient's left side, right side, or even both sides of the body can be affected. Symptoms will depend on which side is affected and how severe the heart failure is - symptoms can be severe.

Pulmonary hypertension - high blood pressure in the arteries in the lungs. If not treated properly, there can be permanent lung damage.

Written by Christian Nordqvist
Copyright: Medical News Today
Not to be reproduced without permission of Medical News Today

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