The heart is basically a pump that pumps blood around the body. Blood contains, amongst other things, glucose and oxygen and every muscle and organ in your body needs these two energy giving elements to function. As a major organ (and muscle) your heart needs a constant supply of glucose and oxygen too.
Blood is delivered to your heart through the three coronary arteries that surround it. If anything prevents blood from flowing easily through these arteries the heart muscle becomes starved of oxygen and has to work harder to get the energy it needs.
Most cardiac deaths are caused by narrowing of the heart arteries due to a process called atheroma (or atherosclerosis) which severely restricts blood flow to the heart. Atheroma is made up of fatty deposits (plaques) which develop on the inner lining of the arteries – like a pipe being ‘furred up’. These plaques are made up of cholesterol, vascular smooth muscle cells and inflammatory cells.

The three coronary arteries

An example of atheroma
23 Minutes – The story of a real heart attack
Coronary heart disease can manifest in several ways:
Angina
When the heart works harder to compensate for narrowed arteries, its function becomes impaired and causes chest pain. This pain is called angina. This is usually experienced during exercise when the narrowed coronary arteries are unable to keep up with the increased demand for oxygen.

An example of a narrow artery
Unstable Angina
Because atheroma disrupts the smooth lining of the arteries, cracks and breaks can occur. If this happens, blood platelets may stick to the surface and form blood clots. These clots can narrow the artery, leading to a sudden deterioration in blood flow and pain in the chest. This can happen at rest, without provocation. This is a sign of critical disease and usually requires urgent medical attention or the artery will block completely, causing a heart attack.

An example of a split in the heart artery
Heart attack
Sometimes referred to as myocardial infarction (MI), a heart attack is when an area of the heart muscle dies because of oxygen starvation. Usually this happens when the build-up of plaque within the artery cracks. Blood platelets then enter the artery, forming blood clots which block the artery completely.

If you are experiencing breathlessness or chest pain you should make an appointment to see your GP or cardiologist
You can arrange to see your local NHS cardiologist, or arrange a private appointment. Professor Banning sees both NHS and private patients from his base in Oxford and can be contacted here.
