4.2.2.4Coronary heart disease: a non-communicable disease
AQA GCSE Combined Science Foundation (8464), Foundation tier · Biology › Organisation › Animal tissues, organs and organ systems
Practise Coronary heart disease: a non-communicable disease. 6 exam-style questions plus unlimited generated ones on this subtopic, at up to four difficulty levels, with full mark schemes and a progress tracker. Free, no account needed.
What coronary heart disease (CHD) is, and how CHD, faulty heart valves and heart failure are treated with drugs (statins), mechanical devices (stents, replacement valves, artificial hearts) or transplants. Expect 'explain' questions on how CHD damages the heart and 6-mark 'evaluate' questions comparing treatments.
Key facts
CHD: fatty material builds up in the coronary arteries → narrower → less blood flow → less oxygen for the heart muscle
Stent: a mesh tube that keeps a coronary artery open
Statins: lower blood cholesterol → slow down fatty deposits
Faulty valve: does not open fully or leaks → heart pumps less efficiently
Replacement valves: biological (animal or human) or mechanical
Heart failure: transplant of a donor heart, or heart and lungs
Artificial heart: usually temporary, until a transplant or while the heart rests
CHD is a non-communicable disease: it cannot be passed from one person to another.
The coronary arteries supply the heart muscle with oxygenated blood.
In CHD, layers of fatty material build up inside the coronary arteries, narrowing them.
This reduces the flow of blood through the coronary arteries, so the heart muscle gets less oxygen for respiration. If an artery becomes blocked, part of the heart muscle can be damaged or die (a heart attack).
Treating CHD
diagram
Stents are small mesh tubes placed inside a narrowed coronary artery to keep it open. Advantages: blood flow improves straight away, only a minor operation, quick recovery. Disadvantages: risks of the procedure (e.g. infection or a blood clot forming), and the artery can narrow again.
Coronary heart disease and a stent. The arrows show blood flow.
Statins are drugs that reduce blood cholesterol levels, which slows down the rate at which fatty material is deposited. Advantages: no surgery; they reduce the risk of CHD developing or getting worse. Disadvantages: they must be taken regularly for a long time, take time to work and can have side effects.
Faulty valves and heart failure
A heart valve may become faulty: it may not open fully, or it may leak. The heart then pumps blood less efficiently, so the person can become tired and breathless.
Faulty valves can be replaced with biological valves (from animals or human donors) or mechanical valves. Mechanical valves last longer, but the patient must take drugs for life to stop blood clots forming.
In heart failure, a donor heart, or heart and lungs, can be transplanted. Problems: a shortage of donors, major surgery, and the risk of rejection, so the patient must take immunosuppressant drugs for life.
Artificial hearts are occasionally used to keep a patient alive while waiting for a transplant, or to let the heart rest as an aid to recovery. They are less likely to be rejected, but there is a risk of blood clots and infection, and parts can fail.
How to answer each type of question
Describe how a treatment works
2 to 4 marksGrade 5
Say what the treatment is or where it goes.
Say what it does to the blood flow or to the fatty build-up.
Example. (a) Describe how a stent helps a person with coronary heart disease. (b) Describe how statins reduce the risk of coronary heart disease.
Show the model answerHide the model answer
(a) The stent is placed inside the narrowed coronary artery (1) and holds it open, so more blood flows to the heart muscle (1). (b) Statins lower blood cholesterol (1), which slows down the build-up of fatty material in the arteries (1).
Don’t lose marks
Saying the fatty material builds up in the heart or in veins. It builds up inside the coronary arteries.
Saying the heart has less blood 'to pump'. The problem is less blood (and oxygen) reaching the heart muscle itself.
Saying statins remove fat from the arteries. They lower blood cholesterol, which slows the build-up.
In 'evaluate' questions, giving only advantages, or giving no conclusion.
Saying artificial hearts are the normal long-term treatment. They are only occasionally used, usually for a limited time.
More tips
Memory tricks
CHD chain: fat → narrow → less blood → less oxygen → less respiration. Each arrow is worth a mark.
Stent = Scaffold (holds the artery open). Statin = Slows (the fatty build-up, by lowering cholesterol).
For every treatment, think RISC: Risks (surgery, clots, infection), Improvement (how fast, how long), Side effects or lifelong drugs, Cost and availability.
Exam technique
'Evaluate' means give advantages and disadvantages, then a judgement with a reason.
Use any data in the question (costs, success rates, waiting times) in your evaluation, quoting the numbers.
Write 'coronary arteries', not just 'arteries' or 'blood vessels', in CHD answers.
Write 'less oxygen for respiration' to link reduced blood flow to damage to the heart muscle.
What each grade needs
What you need to be able to do, from the first marks up to the top grade.
Grade 3
Name the vessels that supply heart muscleThe coronary arteries supply the heart muscle with oxygenated blood.
Grade 4
Describe what happens in coronary heart diseaseLayers of fatty material build up inside the coronary arteries and narrow them.
Grade 5
Describe how stents and statins treat CHDA stent holds the coronary artery open; statins lower blood cholesterol, which slows the build-up of fatty material.
Grade 5
Describe treatments for faulty valves and heart failureFaulty valves are replaced with biological or mechanical valves; heart failure can be treated with a donor heart (or heart and lungs) or, occasionally, an artificial heart.
Quick recall
Cover the answers and test yourself. The app has these as flashcards that come back just before you'd forget them.
Name the device that is used to keep a coronary artery open.
stent
The statements describe how CHD can lead to a heart attack. They are not in the correct order. A Less blood flows through the coronary arteries. B Layers of fatty material build up inside the coronary arteries. C The heart muscle does not get enough oxygen. D The coronary arteries become narrower. Write the letters in the correct order.
B, D, A, C
Sample questions
Written for this site in the style of AQA exam questions. They are not taken from real past papers.
Question 1Easy5 marks
Coronary heart disease is a non-communicable disease.
(a) Which statement describes what happens in coronary heart disease? Tick (✓) one box.[1]
Layers of fatty material build up inside the coronary arteries.
The heart valves become too large.
Red blood cells stick together in the veins.
The pacemaker cells stop working.
(b) Name the device that is used to keep a coronary artery open.[1]
(c) Name the type of drug that is used to reduce the concentration of cholesterol in the blood.[1]
(d) Faulty heart valves can be replaced. Give the two types of replacement valve.[2]
Show the answer and mark scheme
(a)Answer: Layers of fatty material build up inside the coronary arteries.
(b)Answer: stent
stent
(c)Answer: statins
statin(s)
(d)
biological (valve)
mechanical (valve)
Question 2Medium6 marks
Coronary heart disease can lead to a heart attack.
(a) Explain how coronary heart disease can cause damage to the heart muscle.[3]
(b) Explain how statins reduce the risk of coronary heart disease.[2]
(c) Give one disadvantage of treating coronary heart disease with statins.[1]
Show the answer and mark scheme
(a)
fatty material builds up and narrows the coronary arteries
so less blood flows to the heart muscle
so the muscle cells get less oxygen for (aerobic) respiration and may be damaged / die
(b)
statins reduce the concentration of cholesterol in the blood
which slows down the rate at which fatty material is deposited in the arteries
(c)
possible side effects (e.g. muscle pain / liver problems) / they must be taken regularly for life / they take time to have an effect