Atherosclerosis is a progressive disease characterized by thickening of the coronary arteries that supply blood to the heart. The thickening is caused from a plaque buildup, linked to cholesterol levels, primarily the LDL, or low density lipoprotein. The thickening and narrowing of the coronary arteries increases the risk of heart attacks.
Atherosclerosis and Blood Flow
The cause of a heart attack is attributed to atherosclerosis, a buildup of fatty deposits containing cholesterol, which creates a thickening of arteries and partial blockage of blood flow. Constrictions from the atherosclerosis can close up the artery completely, or they can trigger the formation of blood clots that can become lodged due to the narrowing of the artery. Blockage from either case causes the heart to be deprived of necessary oxygen.
Understanding Cholesterol
Cholesterol is a waxy substance found within the human body. Although cholesterol may have the reputation of being an unwanted substance, all cells require it because it is an essential component of all cell membranes. Cholesterol also plays other essential roles in the body, but knowing which type of cholesterol is "good" and which type is "bad" is important in understanding the risk for heart disease and stroke.
Total Cholesterol
The total cholesterol number is the sum of all the cholesterol in the blood. A person with a high total cholesterol level is twice as likely to have heart disease as someone in the desirable rang, according to "Patient Education Management." A total cholesterol level less than 200 mg/dL is desirable. Anything over 240 mg/dL is high and increases the risk of a heart attack.
LDL Cholesterol
LDL is the main source of cholesterol buildup and blockage in arteries, "Patient Education Management" states. It is considered the bad cholesterol because it carries harmful, plaque-building fats toward the heart. The lower the value of LDL, the lower the risk for having an heart attack. Knowing what the desired level of LDL should be depends on a patients degree of risk factors. According to MayoClinic.com, a patient who has a very high risk for heart attack should maintain an LDL below 70 mg/dL. The ideal level of LDL for those who are not in higher risk categories is between 100 and 129 mg/dL. An LDL level of 190 mg/dL and above is considered very high, which is an indication of a greater risk for developing a heart attack.
HDL Cholesterol
As noted in "Patient Education Management," HDL, or high density lipoprotein, helps prevent cholesterol from building up in the artery walls by carrying it in the blood away from other parts of the body back to the liver, which expels it. HDL is considered the "good" cholesterol. This is the only cholesterol measurement where the higher the value, the better. MayoClinic.com indicates that HDL levels of 60 mg/dL and above are best.
References
- "Patient Education Management"; Teach meaning behind cholesterol numbers; L. Randall; August 2008
- "The Nurse Practitioner"; Assessing Coronary Heart Disease Risk and Managing Lipids: L. Braun & R. Rosenson; Decemeber 2001
- Mayo Clinic; Cholesterol levels: What numbers should you aim for
