What causes a heart attack?

What causes a heart attack?
In most cases a heart attack will be triggered by coronary heart disease.

Coronary heart disease is where the coronary arteries, that supply the heart with oxygen-rich blood, become narrower.

This happens over time, as fatty materials build up in the blood vessel.

If a piece of the fatty material then breaks off, it can cause a blood clot.

When the clot is big enough to block the artery it can cut off the blood supply to the heart muscle.

This is a heart attack, which can also be referred to by it's medical names myocardial infarction, acute coronary syndrome or coronary thrombosis.