The heart is a muscle and requires a regular supply of oxygen and nutrients to function. A network of blood vessels known as the coronary arteries supplies the heart. The coronary arteries can become narrowed by the build up of fatty deposits in the artery wall, called atherosclerotic plaques. Blood clots can form on these plaques and block the coronary artery causing a heart attack.
The heart muscle supplied by the blocked artery is starved of oxygen and dies soon afterwards. This can cause the heart to beat in fast dangerous rhythms. The build up of plaques in the coronary arteries increases with age and most people who have significant narrowing are usually over 50 years of age.
There is a hereditary component to the development of atherosclerosis however many factors are involved including smoking, high blood pressure, diabetes and cholesterol levels. Some families carry genes that make them likely to have a very high cholesterol levels. This is known as familial hypercholesterolemia. Families affected usually have several members who have suffered from heart attacks sometimes at very young ages.
In extreme circumstances people can develop fatty deposits around the eyes or in muscle tendons, but usually the only way of telling is to have a blood test. If cholesterol levels are very high they can be treated with tablets. It is essential that the other risk factors such as smoking, high blood pressure, diabetes and diet are also corrected. Exercise can also help reduce the build up of fatty deposits in arteries.
What are the symptoms?
Most people with narrowed arteries will experience heavy or tight chest pain, called angina, or breathlessness, most commonly during exertion, as a warning.
How is it diagnosed?
An ECG at rest will often be normal. An ECG during exercise may show signs that the heart is being starved of oxygen. A test called an angiogram can be used to visualise the arteries and diagnose the condition.
Treatment and advice
Individuals with coronary artery disease should receive all the necessary life-style modification treatment, including smoking cessation, healthy diet and regular exercise. The mainstay of treatment is medication which can relieve the symptoms and reduce the risk of further fatty deposits building-up and a heart attack.
If the symptoms and subsequent investigations suggest a very tight narrowing in one of the coronary arteries then a catheter can be passed through the leg or the arm artery to the heart and attempt to open up the narrowing by inflating a balloon and inseting a metal wire (stent) to keep the artery open (angioplasty).
In more severe cases, where multiple narrowings exist affecting both the right and the left coronary arteries, a bypass operation may be required, to relieve the obstructions.