6. Cardiovascular disease (CVD) and lifestyle

Reminder: Cardiovascular disease (CVD) is the scientific medical term for all types of disease that affect the heart or blood vessels. 

CVD includes coronary heart disease (clogged up arteries with fatty deposits), which can cause heart attacks, stroke, heart failure, and peripheral artery disease.

 

CVD is a medical term to describe diseases of the heart or blood vessels.

CVD is usually associated with the narrowing and blocking of the blood vessels (arteries) that convey oxygenated blood away from the heart.

Arteries become narrowed due to the build up of fatty deposits on the lining of damaged artery walls - often the damage is caused by high blood pressure. The fatty deposits can also cause blood clots.

One such example is coronary heart disease.

Heart disease is one of the major causes of death in the UK and other developed countries.

Cholesterol is made in the liver and transported in the blood.

Cholesterol is important and we need a small amount of blood cholesterol because the body uses it to: build the structure of cell membranes, make hormones like oestrogen, testosterone and adrenal hormones.

Cholesterol also helps your metabolism work efficiently is essential for your body to produce vitamin D.

However, high levels of cholesterol are associated with heart disease.

Smoking is also very bad for you, and not just for causing lung cancer.

When breathed in, the chemicals in tobacco smoke harm your blood cells.

They also can damage the function of your heart and the structure and function of your blood vessels.

This damage increases your risk of atherosclerosis - a disease in which a waxy substance called plaque builds up in the arteries.

 

Coronary heart disease and a heart attack

Coronary heart disease is when the coronary arteries that supply blood to heart muscle become blocked with layers of cholesterol, fats and other materials deposited on the inside of artery walls.

This effectively narrows the arteries restricting the blood flow.

This decreased blood flow means less oxygen is carried to the heart muscles.

A lack of oxygen to work the heart muscles can lead to a heart attack.

There is also an increased risk of blood clots forming - these can block the flow of blood completely, greatly increasing the chance of a heart attack.

See Part 7 for more on stents

 

Strokes

A stroke occurs when a narrowed artery that supplies blood to the brain, becomes blocked by a blood clot.

This deprives the brain of oxygen leading to a life-threatening situation..

Without rapid treatment, the results can be disastrous - death, injury to the brain (e.g. memory) and central nervous system (paralysis and physical coordination).

Recovery can be prolonged and often never complete.

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Key points - Summary of ideas

explaining causes of CVD, heart attacks & strokes what cardiovascular disease and its causes on the syllabus-specifications for students taking the AQA, Edexcel and OCR GCSE level biology examinations (~US grades 9-10).

Cardiovascular Disease (CVD) – Revision Notes

What is Cardiovascular Disease (CVD)?

Cardiovascular disease (CVD) refers to a group of diseases affecting the heart and blood vessels.

CVD  includes conditions such as coronary heart disease (CHD), strokes, and hypertension. CVD is one of the leading causes of death worldwide, and its development is often linked to lifestyle and genetic factors.

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Causes of CVD

CVD can be caused by various factors, including:

• Lifestyle Factors: Smoking, poor diet, lack of exercise, and excessive alcohol consumption.

• High Blood Pressure (Hypertension): Damages artery walls, making them more likely to develop fatty deposits (atherosclerosis).

• High Cholesterol: Leads to plaque build-up in arteries, restricting blood flow.

• Obesity: Increases strain on the heart and raises cholesterol levels.

• Diabetes: Can cause damage to blood vessels, increasing the risk of CVD.

• Genetic Factors: A family history of heart disease may increase an individual's risk.

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Cholesterol and its Role in CVD

Cholesterol is a lipid found in the blood that is essential for cell membranes and hormone production.

However, excessive cholesterol can lead to health problems.

• Low-Density Lipoprotein (LDL) – "Bad Cholesterol": Leads to plaque build-up in arteries, increasing the risk of heart disease.

• High-Density Lipoprotein (HDL) – "Good Cholesterol": Helps remove excess cholesterol from the bloodstream, reducing the risk of CVD.

A high intake of saturated fats can increase LDL levels, while regular exercise and a healthy diet can raise HDL levels.

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Statins – Medication to Reduce Cholesterol

Statins are drugs that reduce cholesterol levels, lowering the risk of developing CVD.

• How They Work: Statins inhibit an enzyme in the liver that is responsible for producing cholesterol.

• Benefits: Lower LDL cholesterol, reduce the risk of heart attacks and strokes, and help prevent further plaque build-up.

• Risks and Side Effects: Can cause muscle pain, liver damage, and increase the risk of type 2 diabetes in some individuals.

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Causes of Heart Attacks and Strokes

• Heart Attack (Myocardial Infarction):

  • Occurs when the coronary arteries supplying oxygen-rich blood to the heart become blocked.

  • The blockage is often caused by a blood clot that forms due to plaque rupture.

  • Symptoms include chest pain, shortness of breath, and nausea.

• Stroke:

  • Happens when blood flow to the brain is disrupted due to a blocked or burst blood vessel.

  • Ischemic stroke (due to blood clot) is the most common type.

  • Symptoms include facial drooping, arm weakness, and speech difficulties (F.A.S.T. signs – Face, Arms, Speech, Time).

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Prevention and Treatment of CVD

• Lifestyle Changes: Regular exercise, a balanced diet, quitting smoking, and reducing alcohol intake.

• Medications: Blood pressure medications, anticoagulants, and statins.

• Medical Procedures: Stents, bypass surgery, and clot-busting drugs (thrombolysis) to restore blood flow.

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Summary of learning objectives and key words or phrases

Understand what is meant by cardiovascular disease (CVD)

Know some of the causes  cardiovascular disease.

Know what can cause a heart attacks or a strokes.

Be able to associate the risk of CVD with smoking and other lifestyle factors, the onset of coronary heart disease from fatty deposits on the walls of arteries, having a safer and appropriate cholesterol level in the blood.

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