Simply select a letter range from the drop-down menu or scroll though the list to find the term you're curious about.

Ablation (radio frequency ablation, RFA)
The application of high-frequency radio waves directly on the electrical system of the heart, usually during a heart catheterization. Ablations can be used to eliminate abnormal sites of electrical activity in the heart that may cause arrhythmias. In many cases, the procedure is highly successful. It is most commonly used for certain types of rapid heart rhythms such as supraventricular tachycardia (SVT).

ACE inhibitors
A class of useful drugs that prevents the formation of natural substances responsible for increasing blood pressure. These drugs reduce the heart's workload and prevent heart muscle damage. Examples are captopril (Capoten®), enalapril (Vasotec®) and lisinopril (Zestril®).

Acidosis
A lowering of the pH in blood tissue due to excessive acid caused by circulation failure or severe lack of oxygen.

Aneurysm
A balloon-like sac in the wall of an artery, vein, or heart caused by a weakening of the wall by injury, disease, or abnormality present at birth.

Angiocardiography
An x-ray method using dye in the bloodstream to show the dimension of the heart.

Angioplasty
A procedure using a deflated balloon on the end of a catheter used to widen narrow arteries.

Antiarrhythmic drugs
Medicines used to treat heart rate rhythm disorders. Frequently used drugs include: lidocaine, procaine, amide, digitalis, propanolol, quinidine, alroprine, and isoproterenol.

Antibody
A substance produced by the immune system to fight infections and foreign substances. Antibodies are produced in response to specific antigens.

Anticoagulant
A drug that delays clotting but does not dissolve existing clots. Tends to prevent new clots from forming on artificial valves and existing clots from enlarging.

Antigen
Substances recognized by the immune system as infectious or foreign. The immune system produces antibodies to fight antigens.

Aorta
The main artery which receives blood from the left ventricle of the heart and flows to the body.

Aortic valve
The heart valve between the aorta and the left ventricle.

Arrhythmia
An abnormal rhythm of the heart.

Arteriography
An x-ray opaque dye injected into the blood stream to study arteries (usually coronary) for damage.

Artery
One of the series of vessels that carries blood from the heart.

Atresia
The failure of a bodily structure to develop and the tissue to fully close as it normally would. Usually present and open at birth.

Atria
(atrium-singular) The two upper holding chambers of the heart.

Atrial Septal defect
A congenital defect in the atrial septum.

Atrial Septum
The wall dividing the right and left atria.

Atrioventricular node
Conducting tissue at the bottom of the right atrium in which electrical impulses must pass to reach the ventricles.

Atrioventricular canal defect (A-V Canal defect)
Also atrioventricular septal defect or endocardial cushion defect. A congenital defect in which defects are present between the atria and ventricles and the tricuspid and mitral valves are abnormal.

Azathioprine
An anti-rejection drug given to transplant patients that suppresses the production of white blood cells.

^ Back to top

B

B Cell
A certain kind of white blood cell that plays a central role in antibody production.

Bacterial endocarditis
A bacterial infection of the inner layer of the heart.

Balloon catheter
Used to dilate a narrow structure. (see angioplasty)

Biopsy
The removal and examination of tissue for diagnosis.

Blood pressure
The pressure exerted by the heart in pumping blood.

Blue babies
A result of insufficient oxygen in the arterial blood. Can be caused by a heart defect, premature birth, or poor respiration.

Bradycardia
An unusually slow heart rate.

Bundle of His
Named after Wilhelm His, an A-V bundle or atrioventricular bundle of small mass fibers. The only known direct connection between the ventricles and the atria that conducts impulses to the ventricular heart muscle.

^ Back to top

C

Cardiac
Relating to the heart.

Cardiac arrest
The blood ceases to circulate and the heart stops beating.

Cardiac Catheterization
putting a catheter into an artery or vein to examine the heart sometimes using a fluoroscope to view the heart.

Cardiologist
A doctor specializing in the diagnosis and treatment of heart disorders.

Cardiopulmonary Resuscitation (CPR)
Used when the heart stops beating, a method of mouth-to-mouth breathing and external cardiac compression to keep oxygenated blood circulating.

Catheter
A fine, flexible tube which is inserted into an artery or vein. It is made of material to which blood will not adhere.

Catheterization
The process of inserting a catheter into a vein or artery and guiding it through the heart chambers and surrounding vessels for purposes of examination or treatment.

Cineangiocardiography
A similar procedure to angiocardiography except that this method uses motion pictures instead of x-ray slides.

Closed heart surgery
Performed on blood vessels in the chest but not in the heart. Does not require a heart-lung machine.

Coarctation
A narrowing of the aorta where the aorta and pulmonary arteries are joined by the ductus arteriosus.

Collateral Circulation
A network of small arteries normally closed. When the coronary artery is blocked, they may open to carry blood to the heart.

Congenital
Existing at birth.

Congestive heart failure
The inability for the heart to pump the blood out of the heart. The build up of fluid on lungs and tissue can be acute or gradual.

Corticosteroids
Hormones naturally produced by the body which can also be manufactured synthetically. High doses of corticosteroids will suppress the immune system. See Prednisone.

Crossmatching
The testing of blood samples to determine the compatibility of a potential donor's and a recipient's blood.

Cyanosis
Caused by insufficient oxygen. Causes a blueness to the skin, lips, and nail beds.

Cyclosporine
A immunosuppressive drug made from soil molds and is taken by the vast majority of transplant recipients. The product name of the first generation of cyclosporine was Sandimmune. Most patients now take the second generation, called Neoral.

^ Back to top

D

Defibrillator
A machine to stabilize normal contraction rhythms.

Dextrocardia
Abnormal position of the heart within the chest. The heart is usually on the left, and in this condition it is on the right.

Diastolic
The bottom of the two blood pressure numbers. Measures the heart at rest.

Digitalis (Digoxin)
A medicine that slows heart rate, strengthens contractions, and helps move fluid away from the body tissues.

Diuretic
A drug that increases the excretion of urine.

Ductus arteriosus
An open artery that connects the aorta and pulmonary artery before birth. Normally closes after birth but if it doesn't, then surgery or medical treatment may be required.

^ Back to top

E

Echocardiography
A procedure in which pulses of sound are transmitted into the body and the echoes from the heart are recorded and charted. The Doppler color flow gives a picture to show the direction of blood flow.

Edema
Swelling due to excessive fluid in the body.

Electrocardiogram (EKG)
A print-out of the electrical impulses produced by the heart.

Endocardium
The inner lining of the wall of the heart.

Extrasystole
A form of arrhythmia often referred to as "an extra heartbeat".

^ Back to top

F

Fibrillation
When the heart muscle fibers contract individually and quickly disabling the heart from pumping effectively.

Fluoroscope
A tool for looking at internal organs.

Foramen ovale
An opening between the right and left upper chambers of the heart. Closes after birth.

^ Back to top

G

Gingival Hypertrophy
Swelling and thickening of the gums. A common side effect of the immunosuppressive drug cyclosporine.

Graft
A transplanted tissue or organ.

^ Back to top

H

Heart block
The electrical impulses causing the heart to beat are slowed or blocked along the pathway between the upper and lower chambers, and usually requires a pacemaker.

Heart-lung machine (cardiopulmonary bypass)
An instrument that oxygenates and pumps the blood during open-heart surgery.

Helper T Cell
A specialized white blood cell that calls upon other parts of the immune system to fight an infection or foreign material.

Heparin
A medicine used to slow the clotting of the blood.

Heterotaxy
Abnormal structure of the heart and other abdominal organs. Usually with multiple defects in the heart and the absence of or multiple spleens.

Holter monitoring
An instrument worn 24 to 72 hours at a time that records EKG information which is later analyzed for arrhythmias and other abnormalities.

Homograft
Also know as Allograft; a heart valve replacement using a human donor valve.

Hypertension
Blood pressure above the normal range.

Hypertrophy
When cells increase in size and cause enlarged tissues and organs.

Hypoplastic
An underdeveloped tissue or organ.

Hypotension
Low blood pressure.

Hypoxia
Low oxygen content in the body.

^ Back to top

I

Immune Response
A defensive action by the immune system to an infection or foreign material.

Interrupted aortic arch
A severe form of coarctation of the aorta.

Invasive
Introduced into the body.

Ischemic heart disease
Ailments caused by a decreased blood supply due to narrowing of the coronary arteries.

^ Back to top

L

Looping
When the looping of the heart is formed early in developmental stages of the fetus.

^ Back to top

M

Mitral valve
The valve between the left ventricle and left atrium having two flaps or cusps that prevent back flow.

Murmur
The noise between normal heart sounds caused by blood flow.

Myocardium
The muscle of the heart wall that contracts to push blood out.

^ Back to top

O

Open-heart surgery
An operation inside the heart while the patient is on a heart lung machine.

Oximetry
A method of measuring the oxygen content of blood.

^ Back to top

P

Pacemaker
An electrical device used to cause heart contractions and control heartbeats.

Palpitations
Irregular heartbeats felt as a skip or momentary cessation of the heart,

Patent Ductus
A blood vessel present prior to birth that bypasses the lungs of the fetus. The Patent Ductus closes shortly after birth.

Patent Ductus Arteriosus
Failure of the Patent Ductus to close shortly after birth as it should.

Pericarditis
Inflammation of the membrane sac.

Pericardium
A membrane sac surrounding the heart and the vessels close to the heart.

Prednisone
A manufactured steroid commonly used as an immunosuppressive drug.

Pulmonary artery
The artery that carries blood to the lungs from the heart.

Pulmonary artresia
Failure of the pulmonary valve or pulmonary artery to develop in utero.

Pulmonary Hypertension
High blood pressure in the blood vessels of the lungs.

Pulmonary valve
The valve between the pulmonary artery and the right ventricle having three cusps that open and close with the heartbeat.

^ Back to top

R

Rejection
An immune system response to a transplanted organ.

Right-heart flow defect
Affecting the ventricle valves and arteries of the right side early on in development.

^ Back to top

S

Septum
The wall dividing the heart chambers.

Stenosis
An obstruction or narrowing of an opening or valve.

Systolic blood pressure
The pressure measured when the ventricle contracts. The highest of the pressures measured.

^ Back to top

T

T Cell
Specialized white blood cells that destroy cells infected by viruses.

Tachycardia
Very quick heart rate.

Tetralogy of Fallot
A malformation where the right ventricle connects to the pulmonary artery causing pulmonary stenosis with a large ventricular septal defect.

Tissue Typing
A blood test used to evaluate the comparability of an organ donor's tissue with the tissue of a potential recipient.

Transplantation (heart)
The placement of a healthy heart from a donor to a patient when the patient's heart can no longer function adequately.

Tricuspid atresia
The failure of the development of the tricuspid valve.

Truncus arteriosus
The failure to divide the single artery in the embryo stage which would be the aorta and pulmonary arteries.

^ Back to top

V

Valve conduit
Tubing used with artificial valves.

Ventricle
One of the lower pumping chambers of the heart.

Ventricular septum
The wall between the left and right ventricle. If the wall is not fully formed, a ventricular septal defect is present.

^ Back to top