Cardiovascular Disease Research Paper
Uploaded by ihatesuchin on Jul 05, 2004
What is Cardiovascular Disease? How may it be prevented and to what extent is heart transplant surgery a sensible solution to the problem of Coronary Heart Disease?
Cardiovascular Disease, or CVD, is Britains biggest killer, responsible for 40% of premature deaths in Britain.
CVD is a comprehensive term for several afflictions of the cardiovascular system - the heart and blood vessels of the body. These afflictions are Coronary Heart Disease (CHD), Atherosclerosis and arteriosclerosis, Angina, Coronary Thrombosis and Myocardial Infarction and Stroke.
Apart from the high mortality rate - it is estimated that CVD kills 140,000 people a year under 75 years old, chronic heart disease causes incapacitation, suffering and pain in many of it's victims. Much heart disease is also self-inflicted and therefore avoidable.
Atherosclerosis and Arteriosclerosis
The underlying cause of CHD, strokes and other diseases of the blood vessels is usually atherosclerosis. Atherosclerosis is caused by the build up of cholesterol and other fatty substances in walls of arteries. Firstly the deposits form small streaks on the endothelium of the artery, but gradually build up to form patches known as atheromatous plaques. The deposit is called an atheroma and causes the arterial walls to thicken, hence narrowing the lumen of the artery.
The onset of an atheromatous plaque may be caused by some physical damage to the artery, sometimes caused by high arterial pressure - hypertension. Smooth muscle cells proliferate at the site of damage and then lipids and cholesterol are deposited from the blood. The cholesterol deposited in the walls may be attacked by free radicals released by phagocytes which may slow down the passage of low density lipoproteins which carry cholesterol back into the blood with the result of increased deposition of cholesterol.
Atheromatous plaques roughen the lining of the artery and disturb the flow of blood, which can stimulate the formation of a clot known as a thrombus. When blood comes into contact with fatty and fibrous tissue, platelets stick to the roughened surface and release clotting factors called thromboxanes. In healthy arteries the amount of thromboxane and prostaglandin is balanced, but in damaged arteries the balance is upset because the endothelial cells lining the artery are damaged so blood clots form.
This can block the blood vessel it is forming in, or small pieces known as emboli can break off and travel through the blood vessels and jam at any narrow point in the system, causing a restriction of blood flow to...