The causes of CHD are caused by the reduction in the blood flow to the heart muscle. The coronary arteries are first narrowed and may eventually be blocked by plaques of atheroma (cholesterol fatty deposits) which also cause atherosclerosis.
There can be even further narrowing or blockage caused by thrombi (blood clots) which are formed on the roughened surface of the plaques.
There are other causes of CHD other that health. This includes personality traits, behaviour and stress. There are some doctors that say to have proven that heart attacks are more frequent in people with ‘type A’ personalities, (people that are very interrupting, impatient, always in a hurry, but also are people that get on with things and achieve).
Although there may be evidence to support that these more physiological and behavioural factors these are much less important that the physical factors such as smoking, and unhealthy diet and a lack of exercise.
It is hard to identify the early stages of CHD because it is symptomless. The main first signs are either angina pectoris or a myocardial infarction.
The pain of angina pectoris is typically brought about by exertion and can be relieved by rest. The pain is a dull ache in the chest or a pressured feeling which may spread up the neck or down the arms. The pain usually comes after a certain amount of exertion (e.g. after walking up the stairs) and then disappears after resting for a while.
Angina can also occur when the heart muscle is working hard and getting too little blood for the amount of effort being expended. If the blood supply to part of the muscle is cut off completely by a blood clot in one of the coronary arteries then you would experience an acute myocardial infarction. The main symptom is intense chest pain of the same type as in angina pectoris, but cannot be relieved by rest and is not brought on by immediate exertion.
The person may also become very cold, sweat profusely, feel weak and nauseated and may even loose consciousness.
Cholesterol is chemically a lipid; it is an important part of body cells. It is also involved in the formation of hormones and bile salts and in the transport of fats in the bloodstream to tissues throughout the body. Most Cholesterol in the blood is made by the liver from a wide variety of foods, especially saturated fats. However, sometimes small amounts are absorbed directly from foods such as eggs and other dairy products.
Both cholesterol and triglycerides are transported around the body in the form of lipoproteins, (particles with a core made up from cholesterol and triglycerides).
The level of cholesterol in the blood can be measured by analysis of blood samples. These show that it is influenced by your diet, heredity (inheritance of a gene) and metabolic diseases (such as diabetes).
There is supporting evidence that having high blood cholesterol increases your chances of getting atherosclerosis (fatty deposits on the inside of the arteries) with this leading to CHD or a myocardial infarction.
The research that has been done, to show that the risk of developing atherosclerosis can be assessed, is by measuring different types of lipoproteins in the blood.
Cholesterol in the form of HDL’s (high density lipoproteins) seems to protect against CHD. On the other hand Cholesterol in the form of LDL’s (low density lipoproteins) or even VLDL’s (very low density lipoproteins) are risk factors.
A group of metabolic disorders cause very high levels of lipids in the blood. People with these disorders are much more susceptible to CHD than normal. Some people will require low fat diets and possibly use of drugs to lower the level of lipids in their blood. Some people who have had relatives that have died of myocardial infarctions or have suffered strokes before the age of 50 are advised to have their own blood checked.
After having looked in depth to both CHD and Cholesterol it is clear to see that there is a link between Cholesterol leading to CHD.
However it is not all Cholesterol that is bad for you. The HDL’s (high density lipoproteins) in the blood are good and protect against getting CHD by picking up the cholesterol from dying body cells and transporting it to the liver where it can be excreted in some form.
It is the LDL’s (low density lipoproteins) and VLDL’s (very low density lipoproteins) that are proven to be greater causes of CHD as they carry the lipids and the cholesterol from the liver to other tissues. In putting the cholesterol back into the tissues it is not able to be disposed of like in the liver meaning that it blocks up slowly, leading to atherosclerosis, in turn steadily building up towards coronary heart disease.
