����ý

Cardiovascular diseases affect the heart.

Coronary heart disease

The heart is a muscular pump. Like all muscles, the heart needs oxygen to carry out aerobic respiration which provides the energy it needs to contract. The coronary arteries supply blood, and therefore oxygen, to the heart muscle.

Risk factors for cardiovascular disease

The risk of developing cardiovascular disease is increased by several factors, including:

• smoking
• high blood pressure
• high levels of salt in the diet
• high levels of saturated fat in the diet

High levels of salt in the diet can lead to increased blood pressure. This may damage the blood vessels, making it easier for fatty deposits to build up.

Heart attacks

A heart attack can happen after a sequence of events:

1. high levels of saturated fats in the diet are linked to an increase in levels of cholesterol in the blood
2. high levels of cholesterol cause fatty deposits to build up in the coronary arteries
3. a blood clot can form on a fatty deposit
4. the blood clot can block a coronary artery
5. some heart muscle cells do not get the oxygen and nutrients they need
6. the person develops chest pain
7. if left untreated then the cells start to die
8. this leads to a heart attack

In the UK about 300 000 people a year have a heart attack.