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Season: 2003

Submitted By: Elizabeth Hurdman

Living with a heart problem can be a challenge. To meet that challenge it is important that you understand your condition and that you feel comfortable with the medical help you receive.

This information is especially written for you, as an adult with a congenital heart defect, and for your family and friends. Its goals are to help you understand what congenital heart disease is, and to answer questions you may have about heart tests, treatments, and lifestyle choices. This resource does not replace medical advice. You are encouraged to talk with your doctor about your specific condition. Remember that your cardiologist thinks of you, not as a case, but as an individual with a special and possibly unique problem.

We have tried to eliminate as much technical jargon as we can. When a medical term is printed in italics the meaning is either given within the text or is linked to the Glossary.

The information presented here has been reviewed by the Canadian Adult Congenital Heart (CACH) Network. The CACH Network is a national multi-disciplinary organization of congenital heart specialists who, coast-to-coast, promote and provide health care to those with congenital heart disease.

Special thanks go to the following for their invaluable contributions: Nanette Alvarez, MD, Yvonne Bessette, RN, David Harrison, MD, Ian Lancashire, PhD, Amanda Reid, RN, Gary Webb, MD.

This resource has been researched and written by Elizabeth Hurdman, BA, B.Ed.

What is a congenital heart defect?

The word congenital means `inborn or existing at birth.` The phrases congenital heart defect and congenital heart disease are often used to mean the same thing, but the word defect is more accurate. Your heart disorder is an abnormality, not a disease. Your defect was caused by the incorrect development of the heart, or blood vessels near the heart, before birth.

How common are congenital heart defects?

At least eight of every 1,000 infants born each year have a heart defect. That is almost one percent of live-born infants. Statistics Canada records tell us that 3,970 children with heart defects were born in this country in 1992. Surgery helps many children whose lives are endangered, or who are severely affected by their heart abnormality. Today it is estimated that some 200,000 Canadians have congenital heart defects.

What caused my congenital heart defect? It is often difficult to determine the cause of congenital heart disease. There is much yet to learn. Specialists believe that about ten percent of heart defects are caused by specific genetic abnormalities. These may result from abnormal chromosomes, as in Down`s syndrome, or from an abnormal gene that is passed down from one generation to the next, as in Marfan syndrome.

As for the remaining 90 percent, a poorly understood combination of genetic predisposition and environmental factors is thought to be responsible. Some congenital heart defects result from abnormalities in the mother`s health during pregnancy. Examples of these conditions are diabetes or systemic lupus erythematosus. Certain infections in the expectant mother may also cause abnormalities. For example, if a mother gets German measles (rubella) while pregnant, her baby has a significant risk of developing a heart defect (approximately 35 percent).

Certain drugs are felt to cause developmental heart abnormalities. This includes the mother`s use of alcohol, `street drugs`, and a number of prescription drugs such as seizure medications. Avoid unnecessary risks. Consult with your doctor before becoming pregnant.

Parents with congenital heart defects are more likely to have affected children than are parents with normal hearts (approximately ten percent versus one percent). Interestingly, the heart defect in your child may not be the same as yours. If one child in your family has a congenital heart defect, the chance of having other children with a heart defect is slightly increased (four percent versus one percent). Some heart abnormalities are more likely to be passed on than others. Your cardiologist or a doctor specializing in genetics can advise you if you have questions or concerns.

How is a congenital heart defect discovered?

As a rule, a serious congenital heart defect is found in infancy. Often an atypical blue colour of the lips or an abnormal noise in the heart (murmur) suggests its presence. Life-threatening or very severe defects are often treated soon after birth with medication or surgery. However, defects that need treatment may be found anytime during childhood. Minor heart defects may not be discovered for many months or years. Your defect may not have been detected until you reached adulthood. If you have one of these conditions, you may require no medical intervention and have no limitations.

What happens after a heart defect is found?

Electrocardiography

An electrocardiograph machine receives tiny electrical impulses from your heart and records them in a zigzag pattern on a moving strip of paper. The impulses are sent through small round discs (electrodes) that are attached to your chest and limbs. The discs are connected to the electrocardiograph machine by cables called leads. The graph of the heartbeat is called an electrocardiogram.

A cardiologist looking at an ECG learns about your heart`s health and rhythm. A normal heart at rest might have an ECG with a pattern similar to the one shown below. Compare it to the ECG labeled `Missed Beat`.

Chest X-Ray

Your chest x-ray reveals information about the lungs and the heart`s size and shape. The amount of radiation from a chest x-ray is extremely small. It will not cause any long-term side effects. However, it should not be performed on pregnant women, especially during the first trimester (three months) of pregnancy. Notice the position of the heart and its major vessels in the normal x-ray shown here. Compare it with the x-ray of the abnormally enlarged heart shown below it.

Echocardiography

An echocardiograph is a cardiac ultrasound. It is a test that uses high-frequency sound waves to create an image of your heart. A Doppler test uses sound waves to measure blood flow. By combining these studies, your doctor learns about the heart`s structure and blood flow.

Notice the difference between an echocardiogram and the chest x-ray above. An echo shows the internal chambers of the heart. The heart in this picture has an atrial septal defect (hole between the two upper chambers). The image is upside down, so the abnormality appears to be in the lower half of the heart. The heart in this picture has an atrial septal defect (hole between the two upper chambers). The image is upside down, so the abnormality appears to be in the lower half of the heart.

After the examinations and tests, your cardiologist will explain your heart condition in detail. Recommendations as to your diet, exercise, work, and any changes in lifestyle will be discussed. Your doctor will also tell you about any possible surgery and medical treatment.

Are there any other special tests?

Sometimes the initial tests will not provide enough information for a diagnosis. Then your cardiologist may suggest that you have additional special tests. These might include any of the following:

• holter monitor (ambulatory ECG)
• heart catheterization
• magnetic resonance imaging (MRI)
• nuclear scans

Holter Monitor

A Holter monitor is a portable electrocardiograph machine. It is about the size of a small tape recorder. You wear the machine continuously for approximately 24 hours while it records your heart beat. Your cardiologist can then learn about irregularities in your heart rhythm occurring during that time.

Heart Catheterization

If your heart condition is very complex, your doctor may recommend cardiac catheterization (heart cath). This procedure is often used in the treatment of coronary artery disease. Those who were diagnosed early in life may have had this test during infancy or in childhood. Today`s technology has greatly improved the comfort and effectiveness of heart `cathing`. It is used only to gather important information that would otherwise not be available.

Your cardiologist, or a doctor specially trained in heart catheterization, inserts a catheter (a small, flexible, plastic tube) into a vein or artery. This blood vessel is usually in the groin area, but sometimes a different site is used. A special x-ray technique allows the doctor to view the procedure. While your doctor watches the monitor, the catheter is slowly moved through the blood vessel until it reaches the heart. Your cardiologist can learn about the defect by taking blood samples and measuring blood pressures through the catheter.

During the heart cath a special fluid (a dye or contrast material) that can be seen by x-ray is injected through the catheter. An x-ray motion picture is recorded that helps to define the heart defect. This procedure is called angiography. Sometimes a heart defect can be treated during a heart cath. These treatments are different for each patient and will be discussed with you beforehand by your cardiologist.

An angiogram is the picture produced by heart catheterization. The shape of the chambers and blood vessels is shown when dye is injected through the catheter. This picture shows an enlargement of the right ventricle. The catheter wire is also visible.

Magnetic Resonance Imaging (MRI)

Magnetic resonance imaging (MRI) is a way of taking highly detailed pictures of the soft tissues in your body. The MRI machine uses magnetism, not radiation, to obtain images. The test usually takes about 60 to 90 minutes to complete. During this time you will lie inside an open-ended chamber while the pictures are taken. The technician may give you an injection. This contains a contrast dye that allows some tissues to stand out better in the pictures.

There is no evidence that an MRI is harmful. However, you should not have an MRI if you have a heart pacemaker, an aneurysm clip in your head, shrapnel or bullets in your body, an ear implant (cochlear), or if you have metal in your eye.

An MRI gives a highly detailed picture of the heart. In this picture you can see how the major blood vessel, the aorta, is `pinched`. This is called coarctation of the aorta.

Nuclear Scans

Nuclear scans provide your doctor with very specialized information. A tiny amount of radioactive material is injected into the bloodstream. A special camera is able to `see` where the material is distributed. The pictures that it takes are processed by a computer. There are different types of nuclear scans.

You may be scheduled fora MUGA (MultiGated Acquisition) scan. It is used to determine how well the ventricles of the heart are working. The picture that it takes is a ventriculogram. If you are scheduled for a perfusion scan, your doctor will be studying the flow of blood to your heart muscle. In this test the cells of the heart muscle absorb the radioactive material. This procedure is often called a thallium test because radioactive thallium is the material used.

How often will I need to see my cardiologist?

Follow-up heart checkups are usually necessary to ensure that your heart maintains its maximum health. These are scheduled more often (that is, days, weeks, months) just after the diagnosis or surgery and less often later. Tests that regularly monitor your progress may be needed, depending upon your problem. Be prepared for

• blood tests
• electrocardiogram
• Holter monitor (24-hour ambulatory electrocardiogram)
• chest x-ray
• Doppler/echocardiogram or exercise testing.

On some occasions you may need follow-up cardiac catheterization.

Is surgery the only treatment for a congenital heart defect?

Having a heart defect does not automatically mean you need an operation. Many heart defects do not need surgery, and some do not require treatment of any kind. It is possible for your cardiologist to find that drug therapy (medical treatment) is effective for you. For example, the drug digoxin can be used to regulate the force of the heart as it beats.

What do I need to know about surgery?

Adults who had operations as children sometimes need new repairs. The wear-and-tear of time, aging, and growth can reduce the effectiveness of their first surgery. Whether your cardiologist finds that you need surgery or re-surgery, you will want to understand your defect, the recommended operation, and the expected results.

Operations are usually done in the same hospital where the diagnostic tests are performed. The facilities will be familiar to you.

The goal of surgery is to repair your defect as completely as possible and to make your circulation as normal as it can be. Sometimes there are several ways to repair the malformed part of your heart or blood vessels. Your surgeon will discuss your options, and the benefits and risks of the operation with you. You may already have had more than one operation if you have a complex heart abnormality. A complicated heart defect may need to be fixed in several stages.

Sometimes a complete repair of the heart is not possible. Surgery, however, may still be the best choice for gaining the best outcome possible for you.

A surgical procedure is always a serious undertaking. Surgery on your heart may be especially frightening. Make sure that you are well prepared for it by talking with both your cardiologist and heart surgeon. Let them know your concerns. Remember that a heart surgery team is a well-trained group of dedicated professionals whose main concern is you.

What does having a problem with `heart rhythm` mean?

Your heart normally beats regularly at 50-150 beats per minute. This rate will vary depending on your age, sex, and degree of fitness. The medical term for an abnormality of heart rhythm is arrhythmia or dysrhythmia.

One type of abnormal rhythm is a very fast heart rate (tachycardia). It reduces the heart`s ability to pump. A very fast heart rate is sometimes related to a congenital heart defect, but it occurs in normal, healthy hearts too. If necessary, medication can be used to slow the heart rate to normal.

A very slow heart rate (bradycardia) can reduce the heart`s pumping ability. Some forms of this condition arise as a result of congenital heart defects. It can also occur after surgery. If your heart rhythm remains abnormally slow, you may need an artificial pacemaker.

There are many other types of arrhythmias. Most are temporary and have little effect on the health of your heart. Examples of these are irregular heart beats and skipped or missed beats. Sometimes an arrhythmia occurs after surgery. If the condition continues or if it affects the function of the heart in a serious way, your doctor may wish to regulate it with medical treatment.

What is congestive heart failure?

During congestive heart failure the heart cannot pump out all the blood that returns to it. As a result, the heart cannot work well enough for the body to get the nourishment it needs for normal work and activity. Congestive heart failure does not mean that the heart stops working. However, fluid can build up in the lungs and make breathing difficult. Fluid may build up in the rest of the body and cause swelling. The signs of congestive heart failure include: fatigue upon exertion, rapid or laboured breathing, swelling, or several of these symptoms. Diuretics are a medication used to help get rid of this extra fluid. You may need to follow a low-salt diet. Other medical treatment may include digoxin or other drugs that can cause the heart to contract with more force.

What should I know about pregnancy and birth control?

Young women with congenital heart defects often have special concerns when they think about having a baby. `Is my heart strong enough for a pregnancy` and `Will my baby have a heart problem?` are two of the most commonly asked questions.

Most women who have had successful heart surgery can have a normal pregnancy and delivery. If you are a woman with a very severe heart problem, pregnancy may be dangerous to both you and your child. It is very important that you consult with your cardiologist before attempting to become pregnant. The chances of your baby having a heart defect are discussed in the section, `What caused my congenital heart defect?`

A pregnant woman should follow a nutritious diet and have regular, medically supervised prenatal care. Smoking, using street drugs, and drinking alcohol must be avoided. She should also have her doctor approve any medicine she uses.

It is also important for women and couples to consider carefully what they choose to use for birth control. Some women should avoid the `pill` and use other forms of birth control instead. Your cardiologist can give you advice about selecting the correct contraceptive method.

What is bacterial endocarditis?

Bacterial endocarditis (BE) is an infection caused by bacteria that enter the bloodstream and settle in the heart lining (endocardium), a heart valve, or a blood vessel. It is a serious illness needing prompt medical attention.

Although endocarditis is uncommon, people with a heart defect have a greater risk of developing it than those with normal hearts. Thus, prevention (prophylaxis) is important. You must use antibiotics as a safeguard before having certain types of surgery or having any dental work. These procedures can allow germs to enter the bloodstream.

Nearly everyone who has an unoperated heart defect needs to take antibiotics to prevent bacterial endocarditis. If you have had heart surgery, you may need this antibiotic protection too. You should be given antibiotics an hour or so before the surgery or dental procedure. Another dose should be given four to six hours later. Use antibiotics before having:

• certain surgeries of the gastrointestinal, genital or urinary tracts,
• dental procedures that may cause the gums or mouth to bleed, and
• the removal of tonsils and adenoids.

Ask your cardiologist about how you can help prevent bacterial endocarditis. Be sure to carry the wallet card made available for you at your clinic. By showing this card to your dentist, family doctor or other physician, you are helping to ensure that you receive the safest and most complete care.

What does a `normal` heart look like?

The normal heart is a strong, hardworking pump about the size of your fist. It is made of three layers of tissue. The thin inside layer is called the endocardium. The middle layer is the muscular myocardium. The protective outer layer is the tough pericardium.

The heart has four chambers. The upper two chambers are the atria and the lower two are the ventricles. The ventricles are larger and it is their strong squeezing action that pumps the blood along its path.

The right side of the heart contains the right atrium and right ventricle. This side pumps blood to the lungs to be refreshed with oxygen. The left side of the heart contains the left atrium andleft ventricle. This side pumps oxygen-rich blood to the body. The right and left sides of the heart are divided by a wall called the septum.

Blood is pumped through the chambers with the help of four heart valves. The valves open and close to let the blood flow in only one direction. Each valve has a set of `flaps` (also called leaflets or cusps). The mitral valve has two flaps. All the others have three flaps.

Valve Location

Tricuspid between the right atrium and right ventricle

Pulmonary between the right ventricle and the pulmonary artery, which leads to the lungs

Mitral between the left atrium and left ventricle

Aortic between the left ventricle and the aorta, the large blood vessel which leads to the body

This diagram shows the four heart valves in a closed position.

How does a `normal` heart work?

Dark blood, low in oxygen, flows through veins to the heart and enters the right atrium. It passes through the tricuspid valve into theright ventricle. The right ventricle pumps the blood under low pressure through the pulmonary valve into thepulmonary artery. The pulmonary artery branches into the left and right pulmonary arteries which lead to the lungs.The lungs provide fresh oxygen to the circulating blood.

Blood returns to the heart from the lungs by the left and right pulmonary veins. It is now bright red It enters the left atrium. From there it flows through the mitral valve and enters the left ventricle. This strong chamber pumps the red oxygen-rich blood out through the aortic valve into the aorta. The aorta takes blood to the body`s general circulation. The blood pressure in the left ventricle is the same as the blood pressure measured in your arm.

Circulation of Blood through the Heart

What are the most common heart defects? Although some defects appear more often than others, none is truly `common`. Sometimes a seemingly simple `hole`, depending on its size and placement, can cause complex problems for the hard-working heart. Cardiologists often place heart defects in to one of two general categories: cyanotic and acyanotic.

Cyanotic Defects

The word cyanosis comes from a Greek word meaning `dark-blue`. It refers to the bluish colour of the skin that results when circulating blood is not supplied with enough oxygen. In cyanotic defects, blood pumped to the body has less than the normal amount of oxygen.

Blood that has been used by the body returns to the heart and is pumped to the lungs to pick up oxygen. Sometimes an abnormality in the structure of the heart prevents or slows the flow of blood to the lungs. A hole or other abnormality may allow `blue` blood to mingle with oxygen-rich blood in the heart. When this mixing occurs, the amount of oxygen that is pumped out to serve the needs of the body is reduced. If cyanosis is mild, it may look like a `ruddy complexion.` If you are severely affected, your lips, finger tips, and toes may have a dark blue colour. The degree of cyanosis may vary with age, activity, and the type of defect.

A cyanotic condition is likely caused by septal defects (holes in the walls dividing the chambers of the heart) in combination with some obstruction (stenosis or atresia) to the normal flow of blood to the lungs. Heart defects that can cause cyanosis include: tetralogy of Fallot,transposition of the great arteries, tricuspid atresia, and truncus arteriosus.

This complex congenital heart abnormality has four typical features:

1. ventricular septal defect (hole between the lower chambers),
2. pulmonary stenosis (narrowing at or around the valve leading to the lungs),
3. hypoplastic right ventricle (enlarged lower right chamber), and
4. placement of the aorta is shifted to the right.

Notice that the mixing of blood from the left and right side of the heart makes `poor-quality`, low-oxygen blood available for the body.

On rare occasions children are born with other very complicated heart defects. For example, some are born with only one ventricle (univentricular heart) instead of two. Sometimes both the pulmonary artery and aorta may arise from the same ventricle (double outlet ventricle) instead of from separate ventricles. In some instances, several heart defects may combine to form a complex cardiac abnormality.

Acyanotic Defects

Many heart defects do not cause cyanosis. They are grouped together in the category `acyanotic`. These abnormalities fall into three general subgroups: holes in the walls of the heart (septal defects), obstructions to the flow of blood, and incomplete development of the heart.

Septal defects

The septum is the wall that separates the left and right sides of the heart. A hole between the two upper chambers or atria is an atrial septal defect (ASD). A hole between the two lower chambers or ventricles is a ventricular septal defect (VSD). Sometimes both the upper and the lower chambers are affected (atrioventricular septal defect). You may have heard these defects described as `holes in the heart`.

Normally, the right side of the heart pumps blood low in oxygen to the lungs. The left side of the heart pumps oxygen-rich blood to the body. If there is a hole in the wall of the heart, blood from the left and right sides can mix. The heart does not work as an efficient pump. Blood pumped to the body may lack adequate oxygen, or blood already rich in oxygen returns to the lungs. The heart will try to compensate by working harder. Persistent overworking can cause it to enlarge.

Some septal defects are so small that they do not affect the heart in an important way. Others are so large or complex that they need to be closed with surgery.

A Heart with an Atrial Septal Defect. This diagram shows the opening between the two upper chambers, the atria, of the heart. Note that oxygen-rich and low-oxygen blood are allowed to mix.

Defects Causing Obstruction in the Heart or Blood Vessels

An abnormal narrowing in the heart`s valves or its blood vessels may partly block the movement of blood. Any one of the heart`s four valves can be affected. The blockage may occur in vessels that return blood to the heart or that carry it away. This narrowing is called stenosis. A stenosis may cause the heart to overwork because it must pump harder than normal to get blood past the narrowing.

The most common forms of obstruction to blood flow are pulmonary stenosis, aortic stenosis, and coarctation of the aorta. Pulmonary stenosis affects the flow of blood to the lungs. Aortic stenosis affects the aortic valve and the aorta, the major vessel leading to the body`s circulation. In coarctation of the aorta a specific section of the aorta is affected.

Diagram of Coarctation of the Aorta. This diagram shows how the aorta becomes constricted, or pinched. The pressure of the blood is affected as it goes to the body.

Those born with a heart defect today have a better-than-ever chance that the problem can be treated and that a normal life will follow. Recent progress in diagnosis and surgery makes it possible to fix most defects, even those once thought to be beyond repair. Both experience and research are building the foundation for improved and effective care. It is possible to believe that even the most complex of congenital heart problems can be managed, and that the quality of life of all those affected will be enhanced.

List of Resources

Goldman, Martin. The Handbook of Heart Drugs: A Consumer`s Guide to Safe and Effective Use. New York: Holt, 1992. 297 pp.

As well as describing some 90 different heart drugs, this book discusses various diagnostic procedures and some treatments. It may be useful for those taking medication. It is available at local libraries and bookstores.

Liberthson, R. R. Congenital Heart Disease: Diagnosis and Management in Children and Adults. Boston: Little Brown, 1989. 268 pp.

This is a medical textbook. Well-organized and well written, it gives a medically technical description of the various congenital heart defects. Reading it would be a challenge for the lay person. Look for it at a medical or university library.

McGoon, Michael D. The Mayo Clinic Heart Book. New York: Morrow, 1993. 368 pp.

This book has excellent illustrations and information, and at approximately $35, represents very good value. It is very readable and clearly describes various heart diseases, tests, and procedures. It is available at many local libraries and bookstores.

Neill, Catherine A., and others. Heart of a Child: What Families Need to Know about Heart Disorders in Children. Baltimore: Johns Hopkins University Press, 1992. 331 pp.

You may find this book of interest although it is written for the parents of children with heart defects. Neill`s book is one of the few that focuses on congenital heart disease and that is written for the general reading public. Check for it at your local library or bookstore.

Rees, Alan M. The Consumer Health Information Source Book. Phoenix, Arizona: Oryx Press, 1994. 206 pp.

This book lists an extensive selection of information resources, from on-line services to pamphlets, books, and periodicals. Although published in the United States, it does not neglect mentioning books and journals from Canadian institutions. It is probably available at your local library, and it is certainly worth a look.

Schlant, Robert C. and Wayne R. Alexander. Hurst`s The Heart, Arteries and Veins. 8th ed.USA. McGraw-Hill, 1994. 2476 pp.

This enormous volume has a large section devoted to congenital heart disease (more than 100 pages). It is a medical textbook, so be prepared for very technical descriptions. Each section is followed by an extensive list of references. If you are comfortable with medical terminology, like researching, and are not easily daunted, this can get you started. Look for it in a medical or reference library.

Weiner, Ed, and the Staff of the People`s Medical Society. Your Heart: Questions You Have. . . Answers You Need. Allentown, PA: The People`s Medical Society, 1992. 184 pp.

This book has a question-and-answer format. The answers are not too detailed, but it is a compact, easy-to-read source of information. Available in local libraries and bookstores, this book costs about nine dollars.

Glossary of Medical Terms Medical language sometimes seems foreign and obscure. Many words do come from classical Latin or Greek because these `dead` languages will not change. In ancient Rome the entrance hall of a home was called an atrium. Doctors now use that word to describe the chambers where blood enters the heart. The words used by a cardiologist to describe your heart and health are chosen with great care. These terms have very precise meanings. They are very specific so as to be accurate in relaying information.

Angiogram: An x-ray picture of the blood vessels of the heart and its blood vessels.

Angiography: The process where dye is injected into the heart or blood vessels so that an x-ray picture can be taken.

Anticoagulants: Drugs that slow the clotting of blood.

Aorta: The main artery that receives oxygenated blood from the left ventricle of the heart and distributes it to all parts of the body, except for the lungs. Click here to see a diagram.

Aortic stenosis (AS): A narrowing of the aortic valve combined with a thickening or stiffening of its cusps (flaps or leaflets).

Aortic valve: The valve, normally having three cusps (flaps), lying between the left ventricle and the aorta. It allows the flow of blood into the major artery taking blood away from the heart.

Arrhythmia (also known as dysrhythmia): An abnormal rhythm of the heart beat. It is not necessarily dangerous or even significant.

Artery: A vessel that carries bloodaway from the heart. Arteries are high-pressure blood vessels in which you can find a pulse. An artery has a thicker wall and smaller inside diameter than a vein.

Atresia (also atretic): The absence of a normal opening.

Atrial fibrillation: Rapid, irregular contractions of the atria followed by the irregular contractions of the ventricles.

Atrial septal defect (ASD): An abnormal opening in the wall (septum) between the two atria.

Atrioventricular septal defect: A complex defect affecting both the upper and lower chambers of the heart, or a large central hole in the atrial and ventricular septum that may involve the mitral and tricuspid valves.

Atrium (plural atria): One of the two upper chambers of the heart. The left and right atria are divided by a wall called theinteratrial septum. Click here to see a diagram.

Blood pressure: The force or pressure exerted by the heart in pumping blood, or the pressure of blood as measured in the arteries.

Bradycardia: A heart rhythm that is slow.

Cardiac (kardia is the Greek word for heart): Concerning the heart.

Cardiology: The study of the heart and its functions in health and disease.

Cardiovascular: Concerning the heart and blood vessels.

Coarctation of the aorta A constriction of the aorta that obstructs the flow of blood to the body. Click here to see a diagram.

Congenital: Existing before or at birth (not necessarily inherited).

Congenital heart defect (CHD): A condition, existing at the time of birth, in which the heart or its major blood vessels are not formed properly and do not work as they should.

Congestive heart failure: The inability of the heart to pump out all the blood that returns to it. This may result in blood backing up in the veins that lead to the heart, or in fluid building up in various parts of the body (lungs, liver and legs).

Connective tissue: The supporting tissues of the body.

Coronary artery disease: Blockage of the arteries that serve the needs of the heart muscle.

Cyanosis: A blue colour of the skin caused by a shortage of oxygen in the blood.

Digoxin: A drug often used in treating congestive heart failure. It makes the contraction of the heart muscle stronger. It is also used to treat some arrhythmias.

Diuretic: A drug that increases urine output. It promotes the excretion of water and salts.

Doppler: A form of ultrasound. Doppler effect creates an image by bouncing sound waves off an object. It is used to assess the characteristics of blood flow.

Down`s syndrome: A number of problems in development occurring from a chromosomal abnormality. These include moderate to severe mental retardation, short fingers, and a mongoloid appearance.

Dysrhythmia: See arrhythmia.

Echocardiography: A diagnostic method in which pulses of sound are transmitted into the body. The echoes returning from the surfaces of the heart and other structures are plotted and recorded as an electronic picture.

Electrocardiogram (ECG or EKG): A graphic record of electrical impulses produced by the heart.

Endocarditis: An inflammation or infection of the inner lining (endocardium) of the heart or heart valves.

Heart catheterization: An examination of the heart by inserting a thin tube (catheter) into a vein or artery and passing it into the heart. This technique is used to measure oxygen levels and pressures in the heart, and to make x-ray movies. Catheters are also used in some heart repair procedures.

High blood pressure (commonly called hypertension): Blood pressure that is consistently above the normal range.

Holter monitor: A tape recording of the ECG (electrocardiogram) usually taken over a 24-hour period.

Inferior vena cava: Major vein leading to the right atrium of the heart. It brings low-oxygen blood from the lower parts of the body (abdomen and legs).

Magnetic resonance imaging: A diagnostic technique that uses magnetism. It produces images of the body`s internal structures.

Marfan syndrome: A rare inherited disease that affects connective tissue. It produces abnormalities in the eyes, skeleton, heart and blood vessels.

Mitral valve: The heart valve between the left atrium and left ventricle. It has two flaps or cusps.

Pacemaker: An electrical device that can be used to replace a defective natural pacemaker. The artificial pacemaker controls the heart`s beating and rhythm by emitting a series of electrical discharges. The `natural` pacemaker of the heart is called the sinus node. The sinus node is a small mass of special cells in the top of the right atrium. These cells send out electrical impulses that cause the heart to contract or `beat`.

Patent ductus arteriosus (PDA): In a fetus and new-born baby, a normal opening is present between the pulmonary artery and the aorta. It should naturally close soon after birth.Patent ductus arteriosus occurs when this opening does not close.

Prophylaxis (phylax is the Greek word for advance guard): A preventive measure.

Pulmonary: Concerning the lungs.

Pulmonary artery: The large artery that takes low-oxygen blood from the right ventricle to the lungs.

Pulmonary atresia (PA): Absence of the pulmonary valve.

Pulmonary stenosis (PS): A narrowing of the pulmonary valve.

Pulmonary (pulmonic) valve: The heart valve between the right ventricle and the pulmonary artery. The pulmonary valve has three flaps or cusps.

Pulmonary veins: These blood vessels bring oxygen-rich blood from the lungs to the left atrium.

Regurgitation: The abnormal backward flowing of blood through a valve of the heart.

Septum: A wall that divides the right and left sides of the heart. The atrial septum separates the top chambers and the ventricular septum separates the bottom chambers.

Stenosis: The narrowing or constriction of an opening, e.g., a heart valve.

Superior vena cava: Major vein leading to the right atrium of the heart. It brings low-oxygen blood from the upper part of the body (head and arms).

Systemic lupus erythmatosus: A recurring illness of the connective tissue associated with the immune system.

Tachycardia: A heart rhythm that is fast.

Transposition of the great arteries (TGA): A condition in which the aorta arises from the right ventricle and the pulmonary artery arises from the left ventricle. In a normal heart these connections are reversed.

Tricuspid valve: The valve between the right atrium and right ventricle. It has three flaps or cusps.

Ultrasound: High-frequency sound vibrations used to create images that help in medical diagnosis. Echocardiography, which shows a picture of the heart, and the Doppler test, which analyzes blood flow, both use ultrasound.

Valve: A structure made up of membrane flaps that lies between two chambers of the heart, or between a chamber of the heart and a blood vessel. Open valves allow blood flow in only one direction. Closed valves normally prevent blood from passing through an opening.

Vascular: Concerning the blood vessels.

Vein: A blood vessel that carries low-oxygen (blue) blood back to the heart. The walls of veins are thin and contain less muscle tissue than arteries.

Ventricle: A pumping chamber of the heart. The right ventricle pumps blood through the pulmonary artery to the lungs, and the left ventricle pumps blood out through the aorta to the body.

Ventricular septal defect (VSD): A defect, or hole, existing in the septum (wall) between the ventricles.