Medical Terms Explained
Down's Heart Group
P.O. Box 4260
Dunstable, Beds, LU6 2ZT, United Kingdom
Tel. & Fax: 0845 166 8061
On-line community:
Reprinted with the permission of Penny Green, Director
© 1998 Down's Heart Group
UK Charity Nº 1011413

An X-ray of the heart assisted by a liquid introduced through a catheter.
A drug whose purpose is to reduce blood clotting (see Drugs Topic Note).
Main artery of the heart which carries blood to the body.
Aortic valve
The valve between the left ventricle (pumping chamber) and the aorta.
Disturbance of normal rhythm of the heart
Vessel which carries oxygenated blood from the heart to all parts of the body.
Atrial Septal Defect - a hole in the septum (wall) between the two atria (collecting chambers) allowing blood to flow between the two sides of the heart (see ASD Topic Note).
Connection that is either blocked or missing altogether.
An upper collecting chamber in the heart which receives incoming blood.
Atrial Ventricular Septal Defect - holes in the septum between the atria and between the ventricles with often a common valve between all four chambers. The most common heart defect in babies with Down' s Syndrome (see AVSD Topic Note).
Narrowing of the pulmonary artery with a band to reduce blood flow to the lungs.
Blue Baby
A baby who has too little oxygenated blood circulating and therefore has a blue tinge to certain parts of the skin (see Cyanosis).
Abnormally slow heart rate.
Relating to the heart.
Cardiac Liaison Sister
A senior nurse in cardiac units to assist families with queries or problems. (see Heart Team Topic Note).
Cardiac Surgeon
A surgeon who specialises in the heart (see Heart Team Topic Note).
A physician specialising in the heart (see Heart Team Topic Note).
Cardiopulmonary Bypass
A machine which takes over the heart' s functions while it is stopped during surgery.
A narrow tube inserted into a vein or artery and fed to the heart, where it is used to assist in finer diagnosis or repair (see Catheterisation Topic Note).
A narrowing in a blood vessel.
Existing at birth.
An excess of fluid in part of the body i.e., the lungs.
Constant Positive Airway Pressure - this is a way of keeping small airways open, often used before a patient is taken off complete ventilation.
Blueness of the skin caused by insufficient oxygen in the blood.
A drug which increases the contraction of the heart muscle (see Drugs Topic Note).
Drugs which assist the kidneys to produce and excrete more urine (see Drugs Topic Note).
A test using sound waves to measure the speed and direction of blood flow in the heart.
A tube to remove fluid from the body.
A tube in the body which conducts fluid.
A technique using high frequency sound waves to produce a picture on a screen of the heart and surrounding blood vessels.
A technique which records the electric currents produced by the heart.
An infection of the heart lining or the heart valves.
see Tetralogy of Fallot.
Heart Failure
Inability of the heart to maintain adequate blood circulation. It does not mean that the heart has ceased to function, but that it is operating seriously below what is required.
Heart Lung Machine
A machine through which the bloodstream is diverted which is used to oxygenate blood and pump it round the body during open heart operations.
Heart Murmur
The sound made by blood flowing through the heart.
ICU (or ITU)
Intensive Care Unit - provides a high level of specialist care immediately after surgery (see Intensive Care Topic Note).
Mitral Valve
Valve between the left atrium and left ventricle.
The noise produced by blood flow within the heart which can indicate a heart defect.
A build up of excess fluid accumulating in body tissue.
Open Heart Surgery
Operations performed on the inside of the opened heart.
A device which controls the rhythm of the heart if it becomes unsettled.
Pacing Wires
Wires which are used to connect a pacemaker to the heart.
(or pediatrics) The branch of medicine dealing with the diseases of children.
Persistent Ductus Arteriosus - a congenital condition where the duct between the aorta and the pulmonary artery sides of the heart fails to close after birth, as it should do, and allows blood to flow between the two sides of the heart (see PDA Topic Note).
The sac or bag surrounding the heart.
A condition where there are an increased number of red cells within the blood.
The estimated outcome of the particular problem a patient has.
Relating to the lungs.
Pulmonary Artery
The large artery which conveys deoxygenated blood from the heart to the lungs.
Pulmonary Hypertension
Elevated pressure of blood flowing into the lungs, caused by the left to right shunting through a septal defect (see Pulmonary Hypertension Topic Note).
Pulmonary Valve
The valve between the right ventricle and the pulmonary artery.
The tissue wall in the heart which divides the left from the right side heart and thus separates the oxygenated from the deoxygenated blood, with their different blood pressures (see Pulmonary Hypertension Topic Note).
A natural or inserted passageway between the two sides of the heart.
A narrowing of a vessel.
The breastbone.
An abnormally rapid heart rate.
Tetralogy of Fallot
A congenital malformation of the heart involving four distinct defects (see Tetralogy of Fallot Topic Note)
Tricuspid Valve
Valve consisting of three cusps, or triangular segments, between the right atrium and the right ventricle.
A structure which opens and closes and when open allows blood flow in one direction and when closed prevents back flow or leakage.
Pertaining to blood vessels.
Drugs which increase the size of the blood vessels and thus reduce blood pressure (see Drugs Topic Note).
A vessel carrying blood back to the heart.
The lower chambers of the heart which act as the pump for the blood' s circulation.
(Ventricular Septal Defect) - a hole in the septum between the two ventricles (pumping chambers) which allows blood to flow between the two sides of the heart (see VSD Topic Note).

  Revised: December 19, 2005.