Glossary

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ablationA procedure used to correct certain types of heart-rhythm disorders. The doctor finds out where the abnormal heart rhythm causing the palpitation is coming from, and uses radio frequency energy to destroy the abnormal electrical pathways.
ACE inhibitorA drug used to treat people with high blood pressure, heart failure or coronary heart disease. ACE stands for 'angiotensin converting enzyme'.
acute coronary syndromeAn umbrella term for situations where the blood supplied to the heart muscle is suddenly blocked.
anaesthetistThe doctor who gives an anaesthetic to make you sleep during an operation.
anginaHeaviness or tightness in the centre of the chest, which may spread to the arms, neck, jaw, back or stomach. Or it may affect just the neck, jaw, arms or stomach. Angina is caused when the arteries to the heart become so narrow due to atheroma or spasm that not enough oxygen-rich blood can reach the heart muscle when the body is making high demands on it - such as during exercise. The pain can also happen when a person is resting.
angiogram / angiographyAn X-ray picture of the blood vessels which shows whether the arteries are narrowed and, if so, how narrow they have become. An angiogram can be used to examine the coronary arteries (a coronary angiogram) or other arteries in your body. For more on this, see 'Diagnosis - Tests'
angioplasty with stentingA treatment to widen a narrowed artery. A catheter (a fine, flexible, hollow tube) with a small inflatable balloon at its tip is passed into an artery in either your groin or your arm. It goes as far as the point in the coronary artery where a blockage has been detected. The balloon is inflated and it flattens the blockage. The balloon is then deflated and a stent made of stainless-steel mesh (see stent) is left in place in the artery to strengthen the artery wall.
Angiotensin receptor antagonistA drug used to control blood pressure or to treat heart failure.
anti-arrhythmic drugA drug used to control a disorder of the heart rhythm.
anticoagulantA drug used to reduce the risk of blood clots forming. Clots are made up of platelets (small blood cells) clumped together, and a protein called fibrin. Anticoagulants act by helping to prevent fibrin from forming.
anti-platelet drugA drug to prevent the blood from clotting. Anti-platelet drugs act by reducing the 'stickiness' of platelets - the small blood cells that can clump together to form a clot which could lead to a heart attack or stroke.
aortaThe large artery (blood vessel) leading out of the left side of your heart and supplying the whole body with blood. See 'For Patients - About Your Heart'
aortic valveThe valve which regulates the flow of blood from the left ventricle into the aorta. See the illustration in See 'For Patients - About Your Heart'
arrhythmiaA disorder of the normal heart rhythm.
arteryA blood vessel carrying blood from your heart to the rest of your body.
aspirinAn anti-platelet drug used to help prevent blood clots forming.
atheromaFatty material that can build up within the walls of the arteries. When atheroma affects the coronary arteries, it can cause angina, heart attack or sudden death.
atherosclerosisThe build-up of fatty material within the walls of the arteries.
atria / atriumThe two upper chambers of your heart. (See the illustration See 'For Patients - About Your Heart'. They act as collecting chambers to fill the ventricles (the two lower chambers of the heart).
atrial fibrillationA type of arrhythmia (abnormal heart rhythm) in which the atria (the upper two chambers of the heart) beat very rapidly. Atrial fibrillation can cause quite unpleasant palpitation and sometimes breathlessness.
beta-blockerA drug that blocks the actions of the hormone adrenaline that makes the heart beat faster and more vigorously.
biopsyA procedure in which a small specimen of tissue is taken for examination.
blood pressureThe pressure of blood in the arteries. The heart is a pump that beats by contracting and then relaxing. The pressure of the blood flowing through your arteries varies at different times in the heartbeat cycle. The highest pressure (called systolic pressure) is when the beat or contraction of the heart forces your blood around the circulation. The lowest pressure (diastolic pressure) is between heartbeats.
bradycardiaA slow heart rate - usually less than 60 beats a minute.
calcium channel blocker / calcium antagonistA drug that is used to increase the length of time during which the heart receives its blood supply with each heartbeat.
capillariesThe smallest of the blood vessels. They join the small arteries to the small veins.
cardiacTo do with the heart.
cardiac arrestWhen the heart stops. This usually happens suddenly, either as a result of a heart attack or if someone has a severe injury and loses a large amount of blood.
cardiac catheterisationWhen a long, flexible, hollow, plastic tube called a 'catheter' is passed into a vein or artery either in the groin or the arm and is gently guided through the blood vessels. This technique is used to take angiograms or to carry out an angioplasty
cardiac enzyme testsBlood tests to measure the level of certain enzymes in the blood. When the heart muscle is damaged after a heart attack, certain enzymes are released into the blood. The amount of enzymes released depends on how severe the damage is.
cardiac rehabilitationIs the process which helps people with heart disease to regain and, if possible, improve their health.
cardiac surgical wardA hospital ward for patients who are going to have, or who have had, heart surgery.
cardiologistA doctor specialising in heart disease.
cardiology wardA hospital ward for patients having tests for heart disease, or who are recovering from a heart attack.
cardiomyopathyA disease of the heart muscle causing the heart to get bigger.
cardiopulmonary resuscitation (CPR)Actions to restore breathing or circulation, or both.
cardiovascularTo do with the heart and blood vessels.
cardioversionA procedure to restore a regular heart rhythm.
catheterA fine, hollow, plastic tube
coronary care unitA specialist unit in a hospital. The unit is just for people with serious heart conditions - for example, people who have had a heart attack - and who need special care, rather than for people who have just had heart surgery.
chest drainA tube which allows blood or fluid which builds up in the chest to be removed safely.
cholesterolA fatty material mainly made in the body by the liver. Too much cholesterol in the blood can increase the risk of atheroma (fatty material) building up in the coronary arteries, leading to coronary heart disease
cholesterol lowering drugA drug to lower the blood cholesterol level.
clot-busterA drug given directly into a vein when there is an urgent need to dissolve a clot - for example, during a heart attack.
congenital heart diseaseHeart conditions in which there are abnormalities of the structure of the heart or major blood vessels. These abnormalities are present at birth and some may be hereditary.
contrast mediumA substance that is injected into a vein so that the blood vessels can be seen more easily during tests such as an X-ray or CT scan.
coronary arteriesThe arteries that branch off the aortic root and which supply blood to the heart muscle
coronary artery bypass surgery / coronary bypass surgeryAn operation to bypass a narrowed section or sections of coronary arteries and improve the blood supply to the heart. For more information see 'Treatment - Surgery'.
coronary heart diseaseWhen the walls of the coronary arteries (the arteries that supply blood to the heart muscle) become narrowed by a gradual build-up of fatty material called atheroma. When atheroma affects the coronary arteries, it can cause angina, heart attack or sudden death.
coronary thrombosisWhen a blood clot forms in a coronary artery. This may lead to a heart attack.
defibrillatorA device which delivers a controlled electric shock through the chest wall to the heart, in order to restore a normal heart rhythm. See also ICD.
diabetesA disease caused when the body does not produce enough insulin, or when the cells of the body can no longer use the insulin. Type 1 diabetes is present from birth. Type 2 diabetes develops later.
digoxinA drug used to treat heart failure and certain abnormal heart rhythms such as atrial fibrillation.
diureticAlso known as 'water tablets'. Diuretics increase the output of water and salt in the urine.
drug-eluting stentA stent is a short tube of expandable mesh, like a scaffold, which is inserted at the part of the artery which is to be widened by coronary angioplasty (see angioplasty with stenting. A drug-eluting stent is a stent which has been coated with medication to help prevent the artery closing off again.
dual chamber pacemaker A pacemaker with two electrical leads. One is attached to the right atrium and one to the right ventricle.
ECGA test to record the rhythm and electrical activity of the heart. ECG stands for electrocardiogram'. For more information, See 'Diagnosis - Tests'.
24-hour ECGContinuous recording of an ECG ('electrocardiogram') over 24 hours to look at the heart rhythm. The recorder produces an ECG which can be analysed later.
echocardiogramAn ultrasound picture of the heart which shows the structure of your heart and how it is working. For more on this see 'Diagnosis - Test'
ectopic beatAn extra heartbeat.
electrophysiological testingA technique for detecting and analysing abnormal heart rhythms.
embolusA clot of blood which starts in one part of the body, breaks off into the circulation and ends up lodged somewhere else.
endocarditisAn infection of the inner lining of the heart, usually affecting the valves.
exerciseECG or Exercise Stress Test When the rhythm and electrical activity of your heart are recorded while you are walking on a treadmill.
GTNStands for 'glyceryl trinitrate'. A drug used as a spray or tablet under the tongue to relieve, or to help prevent, angina attacks.
HDLStands for 'high-density lipoprotein'. This is the 'protective' cholesterol. High-density lipoproteins return excess cholesterol to the liver.
heart attackWhen one of the coronary arteries becomes blocked by a blood clot and part of the heart muscle is starved of oxygen, causing damage to the heart.
heart blockWhen the electrical impulses of the heart are slowed down or delayed by an interruption in the heart's normal electrical activity.
heart failureWhen the pumping action of the heart is inadequate.
heart rateThe number of heartbeats each minute.
hypercholesterolaemia / hyperlipidaemiaWhen there is too much cholesterol in the blood.
hypertensionAlso referred to as high blood pressure, HTN or HPN, is a medical condition in which the blood pressure is chronically elevated.
ICDStands for 'implantable cardioverter defibrillator'. A device which is implanted within the chest wall. It monitors the heart rhythm, senses if there is a severe disturbance in heart rhythm and if necessary delivers an electrical impulse or an electrical shock, to stop the abnormal rhythm. For more information, 'Treatment _Cath Lab'
implantable loop recorderA recording device used for finding out about the cause of infrequent symptoms such as dizzy spells or blackouts. It is implanted just under the skin on the chest. It continuously monitors the heartbeat for up to 14 months, and can record any abnormal events that it is programmed to detect.
ischaemiaWhen not enough blood is being supplied to the tissues or muscle. Cardiac ischaemia causes the pain known as angina
ischaemic heart diseaseWhen not enough blood is flowing through the coronary arteries to the heart.
LDLStands for 'low-density lipoprotein'. This is the more 'harmful' cholesterol. Low-density lipoproteins (LDL) carry cholesterol from your liver to the cells of your body.
lipid-lowering drugA drug to lower the level of cholesterol or triglycerides in the blood.
lipidsFatty material in the blood, including HDL cholesterol, LDL cholesterol and triglycerides.
mitral valveThe valve which regulates the flow of blood from your left atrium to your left ventricle.
mitral valve prolapseWhen a mitral valve bulges backwards into the left upper chamber (atrium) of the heart.
mitral valve stenosisObstruction of the mitral valve caused by narrowing or thickening of the valve.
mitral valvuloplastyA procedure to stretch a narrowed mitral valve.
myocardial perfusion scanA test to assess the level of function of the heart muscle. It also assesses the blood flow to the heart. For more on this test, see 'Diagnosis - Test'
myocardiumThe heart muscle.
pacemakerA device which is implanted in the chest, to stimulate contractions of the heart. For more information, see 'Treatment - Cath Lab'
palpitationWhen you become aware of your heartbeat, for example when it feels as if it is beating abnormally fast or slowly, or irregularly or heavily.
paroxysmalIntermittent. Stops for a while and then starts again.
plateletsSmall blood cells which are essential for clotting.
pneumothoraxWhen the air leaks from the lungs into the chest cavity.
pre-admission clinicA clinic where you can meet the hospital staff, and where all the medical tests and investigations that need to be done before an operation are carried out. See 'Diagnosis - Clinic'
pulmonaryTo do with the lungs.
pulmonary arteryThe artery that carries blood from the heart to your lungs.
pulmonary valveThe valve which regulates the flow of blood from your right ventricle to your pulmonary artery
regurgitationWhen a valve does not close properly, allowing blood to leak backwards.
rehabilitationA way of helping a person to regain his or her independence.
revascularisationAny procedure that restores blood flow to a part of the body.
single chamber pacemakerA pacemaker with one electrical lead, either to the right ventricle or right atrium of the heart.
spasmAn action in the wall of a blood vessel that causes it to narrow and reduce the blood supply to the muscle it is supplying. If the spasm happens in the coronary arteries, it can lead to pain such as angina.
stable anginaAngina that comes on with a particular amount of exercise and is well controlled with drugs.
statinA drug used to reduce cholesterol levels.
stenosisAn abnormal narrowing of a blood vessel or valve, causing obstruction to the normal blood flow.
stentA short tube of expandable mesh which is inserted at the part of the artery which is to be widened by coronary angioplasty. The stent helps to support the artery wall.
stress echocardiographyWhen an echocardiogram is done after the heart has been put under stress - either with exercise or with a drug. For more on this, see 'Diagnosis - Test'
strokeDamage to the brain caused by a lack of blood supply to the brain. The blood supply to the brain can be interrupted either by atheroma or by a blood clot or a blood vessel bursting.
tachycardiaA fast heart rate - usually greater than 100 beats a minute.
thrombolysisDrug treatment to help dissolve a blood clot that is blocking an artery.
thrombolytic drugA drug used to dissolve a clot blocking an artery.
transoesophagealThrough the oesophagus (gullet).
transoesophageal echocardiographyA procedure which involves taking detailed pictures of the heart from the gullet (oesophagus) which lies behind the heart. For more on this, see 'Diagnosis - Test'
tricuspid valveThe valve which regulates the flow of blood from the right atrium to the right ventricle.
troponin testA blood test to measure the level of a protein called troponin which is released into the bloodstream after a heart attack.
unstable anginaAngina which has just developed for the first time, or which was previously stable but has recently got worse or changed in pattern. For example, it can come on even when the person is resting.
valveA structure in the heart (or artificial) to make sure that blood flows in one direction only.
valve stenosisNarrowing of the valve.
valvular heart diseaseWhen one or more of the four valves in the heart are diseased or damaged, affecting the flow of blood in the heart.
veinA vessel carrying blood back from various parts of the body to the heart.
ventriclesThe two main pumping chambers of the heart.
ventricular fibrillationA life-threatening disturbance in the heart rhythm which causes the heart to quiver or 'fibrillate' in a disordered way.
ventricular tachycardiaA condition where there is a fast heart rate in the ventricles (the two larger chambers of the heart).
warfarinA type of anticoagulant drug, used to reduce the risk of blood clots forming.