A

Ablation
Elimination or removal. Cardiac ablation also refers to a procedure that eliminates extra electrical pathways within the heart that can cause fast or irregular heart rhythms.

ACE (angiotensin-converting enzyme) inhibitor
A medication that opens up blood vessels, making it easier for the heart to pump blood forward to the body; also used to lower blood pressure.

Acyanotic
Refers to a group of congenital heart defects in which there is a normal amount of oxygen in the bloodstream, giving a pink color to the lips and nail beds.

Anastomosis
A surgical connection, often between two blood vessels.

Aneurysm
A thin, weakened area in a blood vessel or area of the heart.

Angiography
An X-ray study that uses dye injected into arteries to study blood circulation.

Angioplasty
A non-surgical procedure for treating narrowed arteries.

Antiarrhythmics
Medications used to treat irregular heart rhythms grouped into a number of classes depending on their specific action on the heart and its conduction system. Different drugs are chosen depending on the specific type of arrhythmia. Sometimes these drugs are used in combinations. A few of the antiarrhythmics used include:
Amiodarone
Flecainide

Anticoagulant
A medication that keeps blood from clotting.

Antihypertensive
A medication that lowers blood pressure.

Aorta
The largest artery in the body and the primary blood vessel that carries oxygenated blood out of the heart to the rest of the body.

Aortic arch
The curved portion of the aorta (the large blood vessel that carries oxygen-rich blood away from the heart to the body).

Aortic regurgitation
Backwards leakage of blood from the aorta, through a weakened aortic valve, and into the left ventricle, resulting in stress in the left heart and inadequate blood flow to the body.

Aortic stenosis
Narrowing of the opening of the aortic valve (the valve that regulates blood flow from the left ventricle into the aorta).

Aortic valve
The valve that regulates blood flow from the heart into the aorta.

Arrhythmia (also called dysrhythmia)
A fast, slow, or irregular heartbeat.

Arterioles
Small branches of arteries.

Artery
A blood vessel that carries oxygenated blood away from the heart to the body.

Arteriosclerosis
Commonly called "hardening of the arteries;" a variety of conditions caused by fatty or calcium deposits in the artery walls causing them to thicken.

Asplenia
Absence of the spleen, either from improper development before birth, or due to the surgical removal of the spleen resulting from injury or disease.

Atresia
inadequate development of an organ or part of an organ during pregnancy.

Atrial fibrillation
An abnormal heart rhythm that is fast and an irregular beating of the atria (the upper two chambers of the heart).

Atrial flutter
An abnormal heart rhythm that is a rapid beating of the atria (the upper two chambers of the heart).

Atrial septal defect (ASD)
A hole in the wall between the right and left atria (the two upper chambers of the heart).

Atrial septum
The wall between the right and left atria (the two upper chambers of the heart).

Atrioventricular canal
Refers to a congenital heart defect involving an opening low in the atrial septum, an opening high in the ventricular septum, and abnormal development of the mitral and/or tricuspid valves.

Atrium (plural: atria)
One of two upper chambers in the heart.

Atrioventricular block
An interruption of the electrical signal between the atria and the ventricles.

Atrioventricular (AV) node
A cluster of cells between the atria and ventricles that regulate the electrical current.

B

Bacterial endocarditis
A bacterial infection of the valves and interior surfaces of the heart.

Balloon angioplasty
A procedure performed in the cardiac catheterization laboratory that uses a catheter (tube) with a balloon in the tip to open up a narrowed valve or blood vessel.

Beta blocker
A medication that limits the activity of epinephrine (a hormone that increases blood pressure).

Bicuspid
A valve that has two leaflets.

Biopsy
A procedure in which tissue samples are removed from the body for microscopic examination to establish a diagnosis.

Blood clot
A thick, gel-like mass of blood.

Blood pressure
The force or pressure exerted by the heart when pumping blood; the pressure of blood in the arteries.

Blood pressure cuff
A device placed around the upper portion of the arm to measure blood pressure.

Brady
Prefix meaning "slow."

Bradycardia
Abnormally slow heartbeat.

Bundle-branch block
A condition in which the heart's electrical system is unable to normally conduct the electrical signal.

C

Calcium channel blocker
A medication that lowers blood pressure.

Capillaries
Tiny blood vessels between arteries and veins that distribute oxygen-rich blood to the body.

Cardiac
Pertaining to the heart.

Cardiac arrest
The stopping of heartbeat.

Cardiac catheterization
A diagnostic procedure in which a tiny, hollow tube (catheter) is inserted into an artery or vein in order to evaluate the heart and blood vessels.

Cardiac output
The amount of blood that goes through the circulatory system in one minute.

Cardiologist
A physician who specializes in the medical evaluation and treatment of heart diseases.

Cardiology
The clinical study and practice of treating the heart.

Cardiomyopathy
A disease of the heart muscle that causes it to lose its pumping strength.

Cardiovascular (CV)
Pertaining to the heart and blood vessel (circulatory) system.

Cardioversion
The procedure of applying electrical shock to the chest to change an abnormal heartbeat into a normal one.

Carotid artery
The major arteries in the neck that supply blood to the brain.

Catheter
A small, thin tube; may refer to a tube used during a cardiac catheterization procedure to inject dye, obtain blood samples, and measure pressures inside the heart; may also refer to a small tube used to help drain the bladder during and after a surgical procedure.

Cholesterol
A waxy substance that is produced by the human body. It is also found in animal fats, shellfish, and in dairy products (such as beef, chicken, pork, butter, milk, cheese, and eggs).

Cineangiography
The procedure of taking moving pictures to show the passage of dye through blood vessels.

Circulatory system
Pertaining to the heart and blood vessels, and the circulation of blood.

Closed heart surgery
An operation that repairs problems involving the blood vessels attached to the heart, and may not need the use of the heart-lung bypass machine.

Coarctation of the aorta
A congenital heart defect that results in narrowing of the aorta.

Collateral vessels
New blood vessels that are created by the body to provide extra blood flow to an area when the blood vessel(s) that are already there are too small, narrowed, or blocked.

Computerized tomography scan (Also called CT or CAT scan)
A non-invasive procedure that takes cross-sectional images of the brain or other internal organs; to detect any abnormalities that may not show up on an ordinary X-ray.

Conduction system
The electrical system inside the heart that stimulates the heart to beat.

Congenital
A disease or physical abnormality present from birth.

Congenital heart defect
A heart problem present at birth, caused by improper development of the heart during fetal development.

Congenital heart disease
See congenital heart defect.

Congestive heart failure
A condition in which the heart cannot pump out all of the blood that enters it, which leads to an accumulation of blood in the vessels leading to the heart and fluid in the body tissues. Excess blood in the pulmonary (lung) blood vessels can also occur, leading to fluid accumulation in the lungs.

Coronary arteries
Two arteries that come from the aorta to provide blood to the heart muscle.

Cyanosis
Insufficient oxygen in the blood.

Cyanotic
Appearing blue, due to insufficient oxygen in the blood.

D

Defibrillator
An electronic device used to establish normal heartbeat.

Dextrocardia
A heart that is "flipped over," so that the structures that are normally on the right side of the chest are on the left, and vice versa. The arteries and veins are connected correctly; occurs due to an abnormality in heart development during pregnancy.

Diastole
The time during each heartbeat when the ventricles are at rest, filling with blood and not pumping.

Diastolic blood pressure
The lowest blood pressure measure in the arteries, which occurs between heartbeats.

DiGeorge syndrome (also known as Shprintzen, velo-cardio-facial, and 22q11.2 deletion syndrome)
A genetic disease caused by a deletion of a segment of chromosome material on chromosome No. 22 that results in many different health problems, and affects the normal fetal development of the heart, thymus, and parathyroid glands.

Diuretic
A medication that helps the kidneys to remove excess fluids from the body, decrease edema (swelling) and may lower blood pressure.

Doppler ultrasound
A procedure that uses sound waves to evaluate the heart, blood vessels, and valves.

Double outlet right ventricle
A congenital heart defect in which both the aorta and the pulmonary artery are connected to the right ventricle.

Down syndrome (Also called Trisomy 21)
A combination of birth defects caused by the presence of an extra #21 chromosome in each cell of the body. Many children with Down syndrome also have congenital heart disease - usually atrioventricular canal defect.

Ductus arteriosus
A connection between the aorta and the pulmonary artery that is necessary in fetal life, but becomes unnecessary after birth.

Dyspnea
Shortness of breath.

Dysrhythmia
An abnormal heart rhythm

E

Ebstein's anomaly
Abnormal development of the tricuspid valve during pregnancy, causing an abnormally positioned valve that does not open easily (stenosis) and allows backflow of blood (regurgitation) from the right ventricle into the right atrium.

Echocardiogram (echo)
A procedure that evaluates the structure and function of the heart by using sound waves recorded on an electronic sensor which produce a moving picture of the heart and heart valves.

Edema
Swelling.

Effusion
A collection of fluid in a closed cavity.

Ejection fraction
The measurement of the amount of blood pumped out of the ventricles.

Electrocardiogram (ECG or EKG)
A test that records the electrical activity of the heart, shows abnormal rhythms (arrhythmias or dysrhythmias), and detects heart muscle stress.

Electrophysiological study (EPS)
A cardiac catheterization to study electrical current in patients who have arrhythmias.

Endocardium
The membrane that covers the inside surface of the heart.

Endocarditis
A bacterial infection of the valves and interior surfaces of the heart.

End-to-end anastomosis
A surgical connection of two segments of blood vessel by stitching the open end of one segment to the open end of another segment.

Enlarged heart
A condition of the heart in which it is larger than normal.

Epicardium
The membrane that covers the outside of the heart.

Exercise electrocardiogram (ECG or EKG)
A test to assess the cardiac rhythm and function by having the patient exercise on a treadmill or bicycle.

F

Failure to thrive
Failure to grow and gain weight; often due to increased energy expenditure with congenital heart disease.

Fibrillation
Rapid contractions of the heart muscles.

Fluoroscopy
An X-ray procedure that takes continuous pictures to evaluate moving structures within the body, such as the heart.

Flutter
Ineffective contractions of the heart muscles.

Fontan procedure
A surgical procedure performed to repair heart defects in which only one ventricle is functional. It connects the right atrium to the pulmonary artery, allowing oxygen-poor (blue) blood from the body to flow into the lungs.

Foramen ovale
A hole between the right and left atria, present in all unborn children, that remains open after birth for variable periods of time.

G

Glenn shunt
A surgical connection between the superior vena cava and the right pulmonary artery, allowing oxygen-poor (blue) blood to flow into the lungs.

H

Heart attack (also called myocardial infarction)
Occurs when one of more regions of the heart muscle experience a severe or prolonged decrease in oxygen supply caused by a blocked blood flow to the heart muscle.

Heart block
Interrupted electrical impulse to heart muscles.

Heart-lung bypass machine
A machine that performs for the heart and lungs during open heart surgery.

Heart valve prolapse
A condition of the heart valve in which it is partially open when it should be closed.

Hemoglobin
An element in the bloodstream that binds with oxygen and carries it to the organs and tissues of the body.

High blood pressure (Also called hypertension)
Blood pressure that is above the normal range.

High density lipoprotein (HDL)
The "good" cholesterol that promotes breakdown and removal of cholesterol from the body.

Holter monitor
A portable EKG machine worn for a 24-hour period or longer to evaluate irregular, fast or slow heart rhythms while engaging in normal activities.

Homograft
A blood vessel taken from a tissue donor, used to replace a defective blood vessel, most often the pulmonary artery or aorta.

Hypertrophic obstructive cardiomyopathy
(also called HOCM, hypertrophic cardiomyopathy, asymmetrical septal hypertrophy, or ASH, or idiopathic hypertrophic subaortic stenosis or IHSS)
Enlarged heart muscle that causes impeded blood flow.

Hypoplastic
Refers to an abnormally small organ or blood vessel due to abnormal development prior to birth.

Hypoplastic left heart syndrome
A congenital heart defect in which the left side of the heart is poorly developed, resulting in small mitral valve, left ventricle and aorta.

Hypotension
Low blood pressure.

Hypoxia
Abnormal oxygen content in the organs and tissues of the body.

I

Immunosuppressive medications
Medications that suppress the body's immune system; used to minimize rejection of transplanted organs.

Incision
A cut made with a surgical instrument during an operation.

Inferior vena cava
The large blood vessel (vein) that returns blood from the legs and abdomen to the heart.

Insufficiency
A valve deformity that allows the blood to leak backwards when the valve is closed.

Ischemia
Decreased flow of oxygenated blood to an organ due to obstruction in an artery.

Ischemic heart disease
Coronary artery disease or coronary heart disease caused by narrowing of the coronary arteries and decreased blood flow to the heart.

J

Jugular veins
Veins that carry blood from the head back to the heart.

K

Kawasaki disease
An immune system disorder affecting the heart, particularly the coronary arteries.

L

Left atrium
The upper left-hand chamber of the heart. It receives oxygen-rich (red) blood from the lungs via the four pulmonary veins, and then sends this blood to the left ventricle.

Left ventricle
The lower left-hand chamber of the heart. It receives oxygen-rich (red) blood from the left atrium and pumps it into the aorta, which takes the blood to the body. The left ventricle must be strong and muscular in order to pump enough blood to the body to meet its requirements.

Lesion
An injury or wound.

Lipid
A fatty substance in the blood.

Lipoproteins
Transporters of fatty substances in the blood.

Low density lipoprotein (LDL)
The primary cholesterol-carrying substance in the body. In large amounts, it accumulates inside arteries.

Lumen
The hollow area inside a blood vessel.

M

Magnetic resonance imaging (MRI)
A diagnostic procedure that uses a combination of large magnets, radiofrequencies and a computer to produce detailed images of organs and structures within the body.

Marfan syndrome
A genetic disorder that affects the connective tissue of the body. It causes dilation of blood vessels and abnormalities of cardiac valves.

Mechanical valve
An artificial valve used to replace a diseased or defective valve, most often the aortic valve.

Median sternotomy
An incision in the center of the chest, from the top to the bottom of the breastbone, used for many congenital heart defect repair surgeries.

Mitral valve
The valve that controls blood flow between the left atrium and left ventricle in the heart.

Mitral valve prolapse
An abnormality of the valve between the left atrium and left ventricle of the heart that causes backward flow of blood from the left ventricle into the left atrium.

Monounsaturated fats
Dietary fats, such as olive oil or canola oil, that may lower LDL cholesterol levels.

Murmur
A blowing or rasping sound heard while listening to the heart that may or may not indicate problems within the heart or circulatory system.

Myocardial infarction (also called heart attack)
Occurs when one of more regions of the heart muscle experience a severe or prolonged decrease in oxygen supply caused by a blocked blood flow to the heart muscle.

Myocardial ischemia
Insufficient blood flow to part of the heart.

Myocarditis
Inflammation of the heart muscles.

Myocardium
The muscular layer of the heart.

N

Noninvasive procedure
A diagnostic effort or treatment that does not require entering the body or puncturing the skin.

O

Obesity
Overweight by 30% of the ideal body weight.

Occluded artery
An artery that is narrowed by plaque that impedes blood flow.

Open heart surgery
Surgery that involves opening the chest and heart while a heart-lung machine performs for the heart and lungs during the operation.

Oxygen desaturation
Insufficient amounts of oxygen in the bloodstream. Desaturation can occur when oxygen-poor (blue) blood from the right side of the heart circulation mixes with oxygen-rich (red) blood in the left side of the heart circulation and goes to the body. Normal oxygen saturation in the arteries is 95-100%.

Oxygen saturation
The extent to which the hemoglobin is saturated with oxygen. (Hemoglobin is an element in the bloodstream that binds with oxygen and carries it to the organs and tissues of the body.) A normal oxygen saturation of the blood leaving the heart to the body is 95-100%. The oxygen saturation of the blood returning to the heart after delivering oxygen to the body is 75%.

P

Pacemaker
An electronic device that is surgically placed in the patient's body and connected to the heart to regulate the heartbeat.

Palpitation
A sensation in the chest caused by an irregular heartbeat.

Patent
Open.

Patent ductus arteriosus (PDA)
A blood vessel present in all infants that usually closes shortly after birth. It connects the aorta to the pulmonary artery. When it remains open, it allows extra blood to pass through from the aorta to the lungs.

Patent foramen ovale
An opening in the atrial septum (wall between the right and left atria) that is present in all infants, but which usually closes shortly after birth. When it remains open, it allows extra blood to pass through the opening from the left atrium to the right atrium.

Pericardial effusion
A build up of excess fluid between the heart and the membrane that surrounds it, often due to inflammation.

Pericarditis
An inflammation or infection of the sac that surrounds the heart.

Pericardiocentesis
A diagnostic procedure that uses a needle to draw fluid from the pericardium.

Pericardium
The membrane that surrounds the heart.

Plaque
Deposits of fat or other substances attached to the artery wall.

Platelets
Cells found in the blood that assist in clotting.

Polyunsaturated fat
A type of fat found in vegetable oils and margarines that does not appear to raise blood cholesterol levels.

Post-pericardiotomy syndrome
A build up of excess fluid between the heart and the membrane that surrounds it, often due to inflammation after open heart surgery. ("Post" means after, and "pericardiotomy" means opening the membrane around the heart for open heart surgery.)

Premature atrial contraction (PAC)
An early heartbeat started by the atria.

Premature ventricular contraction (PVC)
An early heartbeat started by the ventricles.

Prophylaxis
Prevention.

Prostaglandin E1
An intravenous medication used to keep a patent ductus arteriosus from closing and preserve blood flow to the lungs.

Pulmonary
Pertaining to the lungs and respiratory system.

Pulmonary artery
The blood vessel connecting the right ventricle to the lungs, allowing oxygen-poor (blue) blood to receive oxygen.

Pulmonary edema
A condition in which there is fluid accumulation in the lungs caused by an incorrectly functioning heart.

Pulmonary valve
The heart valve located between the right ventricle and the pulmonary artery that controls blood flow to the lungs.

Pulmonary vein
The vessel that carries oxygenated blood from the lungs to the left side of the heart.

Pulse oximeter
A device that measures the amount of oxygen in the blood. Normal oxygen saturation in the arteries is 95-100%.

R

Radioisotope
A radioactive material injected into the body so that a nuclear scanner can make pictures.

Regurgitation
Backward flow of blood caused by a defective heart valve.

Renal
Pertaining to the kidneys.

Rheumatic fever
A disease caused by a strep infection that may damage the heart valves.

Right atrium
The upper right chamber of the heart, which receives oxygen-poor (blue) blood from the body and sends it to the right ventricle.

Right ventricle
The lower right chamber of the heart, which receives oxygen-poor (blue) blood from the right atrium and sends it to the pulmonary artery.

Risk factor
A condition, element or activity that may adversely affect the heart.

Ross procedure
A surgical procedure performed to repair aortic stenosis. The patient's own pulmonary valve and base of the pulmonary artery (autograft) replace the defective aorta, while a homograft (blood vessel from a tissue donor) replaces the pulmonary valve and base of the pulmonary artery.

Rubella
An illness that can cause birth defects, including congenital heart disease, if a woman contracts it for the first-time during pregnancy; can be prevented by immunization with the MMR vaccine.

S

Saturated fat
Fat that is found in foods from animal meats and skin, dairy products, and some vegetables. Saturated fats are usually solid at room temperatures and can increase LDL levels.

Septal defect
A hole in the wall between the atria or the ventricles (upper or lower heart chambers).

Septum
The muscle wall between the atria or ventricles (upper or lower heart chambers).

Shunt
A connector to allow blood flow between two locations.

Sinus node
The cells that produce the electrical impulses that cause the heart to contract.

Sinus rhythm
A normal heart rhythm in which each heartbeat originates in the sinus node, and proceeds through the rest of the electrical conduction system normally.

Sinus tachycardia
A heart rhythm that originates in the sinus node and proceeds through the rest of the electrical conduction system but is faster than normal.

Sphygmomanometer
An instrument used to measure blood pressure.

Stent
A device implanted in a vessel used to help keep it open.

Stenosis
Narrowing or constriction of a blood vessel or valve in the heart.

Stethoscope
An instrument used to listen to the heart and other sounds in the body.

Sternotomy
A surgical incision made in the breastbone.

Sternum
The breastbone.

Stress
Mental or physical tension that results from physical, emotional or chemical causes.

Stroke
The sudden disruption of blood flow to the brain.

Subclavian
A blood vessel that branches from the aorta and takes oxygen-rich (red) blood to the head and arms.

Subclavian flap
A surgical procedure performed to repair coarctation of the aorta, using part of the left subclavian artery as a patch to enlarge a narrowed aorta.

Superior vena cava
The large vein that returns blood to the heart from the head and arms.

Supraventricular tachycardia
A fast heart rate that originates in the aorta but does not start in the sinus node.

Syncope
Light-headedness or fainting caused by insufficient blood supply to the brain.

Systole
The time during the heartbeat when the ventricles are pumping blood, either to the lungs or to the body.

Systolic blood pressure
The highest blood pressure measured in the arteries.

T

Tachycardia
Rapid heartbeat.

Tachypnea
Rapid breathing.

Tamponade
An emergency situation that occurs when blood or fluid fills the pericardial sac surrounding the heart, preventing the heart from beating effectively.

Telemetry unit
A small box with wires attached to EKG patches on the chest; used to send information about the heartbeat via radio transmission to healthcare professionals for evaluation.

Tetralogy of Fallot (TOF)
A group of congenital heart defects, including a ventricular septal defect, obstruction to blood flow out of the right ventricle to the lungs, and an aorta that is shifted to the right. Enlargement of the right ventricle occurs as the right ventricle copes with obstruction to blood flow.

Thoracotomy
An incision made on the right or left side of the chest between the ribs, in order to access the heart or lungs during surgery.

Trans fat
Vegetable oil that has been treated with hydrogen in order to make it more solid and give it a longer shelf life.

Transesophageal echocardiography (TEE)
A diagnostic test that uses a long tube guided into the mouth, throat and esophagus to evaluate the structures inside the heart with sound waves.

Transplantation
Replacing a damaged organ with one from a donor.

Transposition of the great arteries (also called transposition of the great vessels)
A congenital heart defect involving abnormal development of the great arteries (the aorta and the pulmonary artery) during the time the heart is forming prior to birth. The aorta ends up being connected to the right ventricle, and the pulmonary artery is connected to the left ventricle, which is the opposite of how they are normally connected.

Tricuspid atresia
A congenital heart defect in which the tricuspid valve and right ventricle do not develop properly, preventing oxygen-poor (blue) blood from reaching the lungs via its normal pathway.

Tricuspid valve
The heart valve that controls blood flow from the right atrium into the right ventricle.

Triglyceride
A fat-like substance found in the blood.

Trisomy 21 (also called Down syndrome)
The presence of three #21 chromosomes in each cell of the body, rather than the usual pair, which causes the features otherwise known as Down syndrome. Many children with Down syndrome also have congenital heart disease - usually atrioventricular canal defect.

Truncus arteriosus
A congenital heart defect involving incomplete separation of the great arteries (the aorta and the pulmonary artery) during the time the heart is forming prior to birth.

U

Ultrasound
A diagnostic tool used to evaluate organs and structures inside the body with high-frequency sound waves.

V

Valves
The "doors" between the chambers of the heart that allow blood to move forward and prevent it from moving backward. The heart valves are called tricuspid, pulmonic, mitral, and aortic.

Valvuloplasty
Repairing a heart valve.

Vascular
Pertaining to blood vessels.

Vasodilator
A medication that dilates or widens the opening in a blood vessel.

Vasopressor
A medication that raises blood pressure.

Vasovagal syndrome
A sudden drop in blood pressure, with or without a decrease in heart rate, that is caused by a dysfunction of the nerves controlling the heart and blood vessels.

Vein
A blood vessel that carries blood from the body back into the heart.

Ventricle
One of the two lower chambers of the heart.

Ventricular fibrillation
A condition in which the ventricles contract in rapid and unsynchronized rhythms and cannot pump blood into the body.

Ventricular septal defect
An abnormal opening in the wall between the right and left ventricles.

Ventricular tachycardia
A condition in which the ventricles beat very quickly.

Vertigo
Dizziness

W

Wolff-Parkinson-White syndrome
An extra electrical pathway that connects the atria and ventricles and causes rapid heartbeat.

X

X-ray
A diagnostic test that uses invisible electromagnetic energy beams to produce images of internal tissues, bones, and organs onto film.