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Pathology and the heart: a glossary of terms
A
Aerobic exercise
Repetitive, rhythmical exercise involving large muscle groups. Uses oxygen and increases your heart and breathing rate. Examples include brisk walking, running, swimming and cycling.
Angina
Tightness or heaviness in the chest, which may spread to the arms, neck, back or stomach. Caused by narrowing of the arteries that supply blood to the heart. Not enough oxygen reaches the heart muscle. Can occur at rest or be brought on by exercise.
Anticoagulant
A drug used to reduce the risk of blood clots forming. Blood clots are made up of platelets (small blood cells) and a protein called fibrin. Anticoagulants act by preventing fibrin from forming.
Aorta
The large artery that carries blood from the heart to the rest of the body.
Arrhythmia
A disorder of the normal heart rhythm.
Artery
A blood vessel that carries blood from the heart to the rest of the body. The aorta is the largest artery. Smaller ones branch off the aorta to supply every part of the body. The pulse you can feel in your arm or neck is caused by blood being pumped through an artery.
Atheroma
Fatty material that can build up in the wall of arteries, making the lumen (hole in the middle) smaller. When atheroma affects the arteries of the heart it can prevent enough oxygenated blood (blood carrying oxygen) reaching the heart muscle. This can cause angina or a heart attack. Atheroma can build up for many years before causing a problem.
Atherosclerosis
The build up of fatty material in the walls of the arteries.
Atria (singular atrium)
The two upper chambers of the heart. They act as collecting chambers for blood and fill the ventricles (the larger, lower chambers).
Atrial fibrillation
This is a type of arrhythmia, when the atria (upper heart chambers) beat very quickly. This can cause palpitations or breathlessness.
Autopsy
Also called post mortem, examination of the body after death to find out why someone died. Statistics about heart disease are often obtained from post mortem studies.
B
Beta-blocker
A drug that blocks the action of the hormone adrenalin on the heart. Adrenalin usually makes the heart beat faster, for example when you’re scared or excited. Beta-blockers prevent this from happening.
BHF
The British Heart Foundation is the UK’s biggest heart charity. The BHF invests millions of pounds in research into heart disease each year. For more information please visit the BHF website at www.bhf.org.
Biochemistry
Also called clinical biochemistry, the pathology speciality that is concerned with the analysis of body fluids such as blood and urine. Clinical biochemists can diagnose, treat and monitor diseases by interpreting the level of different chemicals in samples. In the context of heart disease, these tests might include testing for cardiac enzymes, diabetes and blood cholesterol.
Biopsy
A procedure in which a small amount of tissue is taken for examination under the microscope. Biopsies are examined by specialist doctors called cellular pathologists.
Blood pressure
This is the pressure of the blood in the arteries and is caused by the heart pumping blood by contracting and relaxing. When you have your blood pressure taken, two readings are recorded. The higher one (systolic) measures the maximum pressure when the heart contracts. The lower reading (diastolic) measures the lowest pressure when the heart is relaxing between heartbeats.
BMI
Body mass index is a way of working out whether someone is a healthy weight. It is calculated by dividing your weight (in kg) by your height (in m) squared. For example, if you weigh 60kg and are 1.7m tall, your BMI is 60 divided by (1.7x1.7) = 20.8, which is within the normal range. The normal range is 18.5 to 25. Under 18.5 is underweight, 25 to 30 is overweight, over 30 is obese.
BNP
B-type natriuretic peptides – hormones that are produced by the cells of the heart muscle. A high level of BNP can be a sign of heart failure. BNP is one of the chemicals measured by chemical pathologists and clinical biochemists.
C
Capillaries
These are the smallest blood vessels in the body. They join the smallest arteries to the smallest veins.
Cardiac
To do with the heart.
Cardiac arrest
When the heart stops. This usually happens suddenly, for example when someone has a heart attack.
Cardiac enzyme tests
Blood tests to measure the level of certain enzymes (chemicals) in the blood. When the heart is damaged after a heart attack, enzymes are released into the blood and can be measured by chemical pathologists. The amount of enzymes in the blood depends on how severe the damage is.
Cardiac pathologist
A pathologist specialising in the pathology of heart disease.
Cardiologist
A doctor specialising in diseases of the heart.
Cardiomyopathy
Diseases of the heart muscle. This may cause the heart to get bigger and prevent it from working properly.
Cellular pathology
The group of pathology specialties that look at changes in cells and tissues using a microscope to make a diagnosis. Cellular pathologists look at biopsies from the heart to see if there is any evidence of infection or, following a heart transplant, evidence of rejection. Some cellular pathologists perform autopsies on people who have died from heart disease.
Coxsackie virus
A virus that can cause myocarditis (inflammation of the heart muscle)
CPR
Cardiopulmonary resuscitation – actions taken to restore breathing and circulation when someone has had a cardiac (heart) or respiratory (breathing) arrest.
Cardiovascular
To do with the heart and blood vessels.
Cholesterol
A fatty material mainly made in the body by the liver. Too much cholesterol in the blood can increase the risk of developing atheroma, leading to coronary heart disease.
Congenital heart disease
Heart conditions in which there are abnormalities of the structure of the heart or major blood vessels. These abnormalities are present at birth and may be hereditary. Paediatric pathologists specialise in the study of diseases of babies and children, including congenital heart disease.
Coronary arteries
The blood vessels that branch off the aorta to supply blood to the heart muscle.
Coronary heart disease (CHD)
When the walls of the coronary arteries become blocked by atheroma, causing angina, heart attack or sudden death.
Coronary thrombosis
When a blood clot forms in a coronary artery, preventing blood from reaching the heart muscle. This may lead to a heart attack.
D
Defibrillator
A device which delivers a controlled electric shock through the wall of the chest to the heart to try to restore a normal heart rhythm.
Diabetes
A disease caused when the body does not produce enough of the hormone insulin or the body’s cells don’t respond to insulin. Type 1 diabetes is present from birth, type 2 develops later.
Diastolic blood pressure
The lowest blood pressure measured when the heart is relaxing between heartbeats.
E
ECG
Electrocardiogram – a test to record the rhythm and electrical activity of the heart.
Echocardiogram
An ultrasound picture of the heart to look at the structure and how it is working.
Endocarditis
An infection of the inner lining of the heart, usually affecting the valves.
Enteroviruses
A group of viruses, some of which can cause myocarditis (inflammation of the heart muscle) e.g. Coxsackie virus.
Exercise ECG
When the rhythm and electrical activity of your heart are measured while you are exercising, for example walking on a treadmill or pedalling on an exercise bike.
F
Familial hypercholesterolaemia (FH)
An inherited condition in which the blood cholesterol level is very high.
Full blood count
A blood test to measure the level of haemoglobin and white blood cells in the blood. A low haemoglobin level might be due to anaemia, which can cause the heart to beat faster. A high white cell count may be due to infection, which can also cause an increase in heart rate. Haematologists are the pathologists who specialise in diseases of the blood and who interpret test results including the full blood count.
G
Genetic
Relating to genes or heredity – the characteristics that parents pass on to their children.
Genetics
The pathology specialty concerned with how diseases are passed on from parents to children.
GP
General practitioner, or family doctor.
H
Haematology
The pathology discipline involved in the care and treatment of patients with blood disorders such as anaemia.
HDL
High density lipoprotein. This is the ‘protective’ or ‘good’ type of cholesterol. HDLs return excess cholesterol to the liver, removing it from the blood where it can contribute to the formation of atheroma.
Heart attack
When 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 failure
When the pumping action of the heart is inadequate.
Heart rate
The number of times the heart beats each minute.
Hereditary
Passed on from one generation to the next.
High blood pressure
Also known as hypertension. Smaller blood vessels become narrow and cause the pressure to build up. High blood pressure is a risk factor for coronary heart disease.
Histocompatibility and immunogenetics
The study of organ transplants and tissue matching. These pathologists make sure that transplanted organs are suitable for the recipient to try and avoid the organ being rejected.
Histopathology
Another name for cellular pathology.
Hypercholesterolaemia (or hyperlipidaemia)
When there is too much cholesterol in the blood.
I
Immune system
The cells and proteins in the blood and tissues that help protect your body against attack from bacteria and viruses.
Immunology
The science of disorders of the immune system.
Ischaemia
When not enough blood is being supplied to the tissues or muscle. Cardiac ischaemia causes the pain of angina or a heart attack.
Ischaemic heart disease
When not enough blood flows through the coronary arteries to the heart.
L
LDL
Low density lipoprotein. This is the more ‘harmful’ or ‘bad’ type of cholesterol. LDLs carry cholesterol from the liver to the cells of the body.
Left ventricular hypertrophy
When the muscles of the left ventricle become thickened. This happens when the muscle has to work very hard, for example when the blood pressure is high or when there is an obstruction to the outflow of blood, such as a narrowed valve.
Lipids
Fatty material in the blood, includes HDL cholesterol, LDL cholesterol and triglycerides.
M
Medical Microbiology
The branch of pathology which deals with the investigation, treatment and monitoring of infections.
Mitral valve
The valve that regulates the flow of blood from the left atrium to the left ventricle.
Mitral valve stenosis
Obstruction of the mitral valve caused by narrowing or thickening of the valve.
Mono-unsaturated fat
A type of fat found in foods such as olive oil, rapeseed oil and avocado and some margarines and spreads.
Murmur
An unusual sound from the heart, heard while listening with a stethoscope. It is different from the normal sound of the heart.
Myocardial infarction
A heart attack.
Myocarditis
Inflammation of the heart muscle, often caused by infections.
Myocardium
The heart muscle.
O
Obesity
Being very overweight or having too much body fat.
Oedema
Swelling caused by fluid.
Omega-3
A type of fatty acid found in oily fish such as mackerel, pilchards, sardines, salmon, trout and fresh tuna.
Osteoporosis
Thinning of the bones, increases the risk of broken bones.
P
Pacemaker
A device which is implanted in the chest to stimulate the contractions of the heart.
Paediatric pathology
The branch of pathology concerned with diseases and disorders of babies and children. Paediatric pathologists look at samples under the microscope and also perform autopsies following the death of a baby or child.
Palpitation
When you become aware of your heartbeat, for example when it feels as if it is beating abnormally fast or slowly.
Passive smoking
When someone inhales another person’s smoke.
Peripheral arterial disease
Disease of the arteries that supply the blood to the limbs.
Platelets
Small blood cells, which are essential for clotting.
Polyunsaturated fat
A type of fat found in foods that come from plants and fish, such as cornflower oil, sunflower oil, fish oil and some margarines and spreads.
Post mortem
Also called autopsy, examining the body after death to establish the cause of death.
Prognosis
Outlook. Forecast of the course of a disease.
Pulmonary
To do with the lungs.
Pulmonary artery
The artery that takes blood from the heart to the lungs.
Pulmonary valve
The valve that regulates the flow of blood from your right ventricle to your pulmonary artery.
R
Risk factor
Something that increases the risk of getting a disease such as heart disease. Risk factors for coronary heart disease include high blood pressure, smoking, high cholesterol, diabetes and physical inactivity.
S
Saturated fat
A type of fat found mainly in food from animal sources, particularly dairy and meat products.
Statin
A drug used to reduce cholesterol levels.
Streptokinase
A drug used to help dissolve a blood clot that is blocking an artery.
Stroke
Damage to the brain caused by a lack of blood supply to the brain. The blood supply may be interrupted by a blood clot or a vessel bursting.
Systolic blood pressure
The highest blood pressure, occurs when the contraction of the heart forces blood around the circulation.
T
Tachycardia
A fast heart rate – usually greater than 100 beats a minute.
Thrombolysis
Drug treatment to help dissolve a blood clot that is blocking an artery.
Thrombosis
When a blood clot forms in the blood vessels or heart.
Thrombus
A blood clot.
Tissue
A group of similar cells that perform a specialised function e.g. heart muscle, artery wall.
Transplant
An operation to replace the entire heart with one from someone else.
Tricuspid valve
The valve that regulates the flow of blood from the right atrium to the right ventricle.
Triglycerides
A fatty material found in the blood.
Troponin test
A blood test to measure the level of a protein called troponin, which is released into the bloodstream after a heart attack.
U
Unsaturated fat
A type of fat found mainly in foods from plant and fish sources.
U and Es
‘Urea and electrolytes’ – a blood test measuring the level of chemicals such as sodium and potassium in the blood. Very high or low levels of these chemicals can cause arrhythmias. Chemical pathologists (doctors) and clinical biochemists (scientists) are the pathology professionals involved in the interpretation of these blood tests.
V
Valve
A device to make sure that fluid flows in one direction only. Valves are present in the heart and the veins.
Valvular heart disease
When one or more of the four heart valves are diseased or damaged, affecting the flow of blood in the heart.
Vascular
To do with blood vessels.
Vein
A vessel carrying blood back from various parts of the body to the heart.
Ventricles
The two main pumping chambers of the heart.
Virology
The pathology discipline concerned with the study of viruses and the diseases that they cause. Viruses can infect the heart, causing myocarditis (inflammation of the heart muscle).
W
Warfarin
A type of anticoagulant drug, used to reduce the risk of blood clots forming.