Cardiovascular Disease (Heart Attacks, Strokes and Circulation)
What is Cardiovascular Disease?
Cardiovascular disease refers to disease that is caused by the build up of cholesterol rich deposits inside our arteries. These deposits are known as ‘atheromatous plaques’.
These deposits may cause narrowing of an artery and thus restrict the blood supply to the organ that the artery supplies. The 3 main areas that are affected by cardiovascular disease are:
1. The heart
2. The brain
3. The legs and feet
The coronary arteries which supply the heart muscle are a critical area that may be affected. Narrowing of a coronary artery may result in angina which manifests as chest pain and which may be an important warning sign as to an impending heart attack. A heart attack results when the atheromatous plaque ruptures and clot forms which causes a complete blockage of the artery and starvation of blood supply to that area of the heart. Approximately 1 in 4 persons (25%) who suffer a heart attack die within a month.
Similarly, a stroke occurs when one of the arteries that supplies the brain is blocked by a clot on a ruptured atheromatous plaque. The damage to the brain may result in paralysis of a limb, face, speech impairment or death.
Narrowing or obstruction of arteries that supply the legs and feet may cause cramping pain in the calves on walking (we call this ‘claudication’) and, when severe, may result in gangrene which requires amputation.
What causes Cardiovascular Disease?
We recognize a number of factors which put a person at risk to developing the atheromatous plaques that cause cardiovascular disease:
- Cholesterol and Triglycerides:
Cholesterol is an essential part of all cells in the body. Too much cholesterol, especially bad cholesterol (LDL-cholesterol) may result in the buildup of the cholesterol rich plaques inside your arteries. Good cholesterol (HDL-cholesterol) assists in removing bad cholesterol from the blood by delivering it for breakdown by the liver.
Triglycerides are another form of fat in the blood that is being linked to heart disease.
Lowering cholesterol has been shown to reduce the risks of heart attacks and strokes.
What are good levels? The numbers:
Bad (LDL) cholesterol:
For a person who has had a heart attack or stroke we aim for LDL-cholesterol less than 1.8mmol/l
High Blood Pressure (Hypertension)
Hypertension is common and affects xxx people. It becomes more common as we get older and is also associated with overweight, lack of exercise, excess alcohol, high salt intake and smoking.
It causes damage to the blood vessels, heart, kidneys and is a major cause of heart attacks and strokes.
‘High blood pressure’ is considered a blood pressure of higher than 130/80 measured on 2 different readings.
The majority of Type 2 diabetics are overweight and also have high blood pressure and high cholesterol levels. This causes a dramatic increase in cardiovascular risk. According to the American Diabetes Association persons with diabetes have a 2- 4 x increased risk of dying from a heart attack or stroke as a non-diabetic and heart disease is the leading cause of death in diabetics.
Thus, all diabetics are considered to be at increased cardiovascular risk.
Follow this link to see whet your BMI is:
Obesity is an increasing problem round the world, including in South Africa. According to a recent South African survey 70% of women, 39% of men and 13% of children are obese.
The distribution of fat around the abdomen is most closely linked to cardiovascular risk and for this reason measurements of waist circumference are used in conjunction with BMI to determine the cardiovascular risk.
Table 1 : Definition of Overweight and obesity.
|Weigh Categories for adults as per BMI||BMI (kg/m2)|
|Normal||18.5 – 24.9|
|Overweight||25 – 29.9|
|Severe Obesity||≥ 35 (Class II obesity)|
|≥ 40 (Class III obesity)|
Table 2: Waist circumference
|Increased Risk: Waist circumference|
Approximately 1 in every 5 deaths from heart disease is caused by smoking.
Exposure to smoke, either directly or from others (passive smoking), increases the buildup of atheroma in the blood vessels, increases the blood pressure and increases the risk of all forms of cardiovascular disease.
Quitting smoking significantly reduces your risk of heart attacks and strokes.
Genetics (Family History)
A history of a heart attack of stroke before the age of 50 yrs in a direct family member (Mother, father sibling etc.) is a predictor that there may be genetic factors that result in an increased risk of cardiovascular disease.
In South Africa we have a large population of people of Afrikaner descent, who have Familial Hypercholesterolaemia. They have been identified as inheriting an abnormal gene from one or both of their parents. They have very high cholesterol levels and their risk of heart disease is especially high.
For more information:
All studies have been approved by SAHPRA and relevant Ethics committee