CVD: Risk Factors & Effects
Causes of cardiovascular disease
- Cardiovascular disease is not just one disease, but it describes any disease that affects the heart and/or blood vessels
- An example of a type of cardiovascular disease is coronary heart disease (CHD)
- Like all cells in the body, cardiac muscle cells need a supply of blood to deliver oxygen and glucose and to remove waste products such as carbon dioxide
- The blood is supplied to the heart by the coronary arteries which branch off directly from the aorta
- The heart cells need to constantly respire, so it is vital that it receives a constant supply of oxygen
Coronary arteries around the heart diagram
The coronary arteries supply the heart with oxygenated blood and can lead to cardiovascular disease if damaged
- In CHD, layers of fatty material called an atheroma build up inside the coronary arteries
Atheroma build up in coronary arteries diagram
Build up of an atheroma in the coronary arteries narrows the lumen
- The flow of blood through the arteries is reduced, resulting in a lack of oxygen for the heart muscle
- Partial blockage of the coronary arteries creates a restricted blood flow to the cardiac muscle cells and results in severe chest pains
- Complete blockage means cells in that area of the heart will not be able to respire aerobically, leading to a heart attack
The difference between blood flow in a healthy artery and a CHD artery diagram
The effect of a narrowed lumen in a coronary artery is reduced blood flow to the heart
Risk factors of cardiovascular disease (CVD)
- There are several risk factors which will increase the chances of coronary heart disease:
- Poor diet high in fat and salt
- A poor diet can lead to weight gain
- Carrying extra weight puts a strain on the heart
- Increased weight can lead to Type 2 diabetes which further damages your blood vessels
- High blood pressure
- This increases the force of the blood against the artery walls and consequently leads to damage to the vessels
- High blood cholesterol
- Speeds up the build-up of fatty plaques in the arteries leading to blockages
- Smoking
- Chemicals in smoke cause an increase in plaque buildup and an increase in blood pressure
- Carbon monoxide also reduces the oxygen carrying capacity of the red blood cells
- Genetic factors
- Some people have a genetic code that can cause CVD, for example, some babies are born with a small hole in their septum between their atria and this can be caused by DNA
- Or they can have an increased risk of CVD due to their DNA, but there may not be a 100% chance of it occurring
- A lack of exercise
- This is linked to the poor diet factor where carrying extra weight puts a strain on the heart
- Exercise helps to lower blood pressure and blood cholesterol, which decreases the risk of CVD
Examiner Tip
Note that if you are asked in an exam to state a risk factor of CVD and you answer "poor diet", you cannot get the mark. You have to be specific about the diet being high in fat and/or salt in order to gain the mark