Cardiovascular disease is the leading cause of death worldwide, and it kills about 60 people under retirement age every day in the UK.
Cardiovascular disease is a general term that covers all health problems associated with heart or circulatory system. This system made up of the main blood vessels, the arteries and veins, and the smaller capillaries that take blood to and from the tissues and organs.
The main events due to cardiovascular disease are angina and heart attack, which is due to coronary heart disease, and stroke, which can also be called a brain attack. Cardiovascular disease can also cause problems in the limbs or lungs if blood vessels taking blood to them become narrowed or blocked.
What are the causes?
Cardiovascular disease is due to the process of atherosclerosis that occurs in the arteries as the body ages. Atheroma, also called fatty deposits or plaques, build up and thicken the artery walls. High levels of circulating low-density cholesterol (‘bad cholesterol’) accelerate this process, adding layers of fat within the arteries. This is the basic underlying process that occurs in all types of cardiovascular disease but the effects and symptoms vary depending on the site of the affected blood vessels.
The major sites affected by diseased arteries are the heart, the brain and the limbs:
The heart: when atherosclerosis affects the arteries supplying your heart, this reduces the flow of blood to the heart muscle. As incoming blood delivers oxygen, this means that the heart muscle cannot work efficiently. If you exercise, or just run for the bus or up some stairs, this puts strain on the heart muscle and causes typical angina pain. When the coronary arteries allow no blood flow, the oxygen supply to the muscle of the heart is cut off altogether. This causes the affected area of heart muscle to die, and the result is a heart attack, a medical emergency that can be fatal if not treated quickly.
The brain: narrowing of the arteries can lead to blood clots in the brain, which cut off the oxygen supply to large areas of brain tissue. This is known as a cerebral thrombosis. If the clot causes the vessel to rupture, the bleeding that follows is a cerebral haemorrhage. Both these events cause damage to the brain and the resulting illness is commonly known as a stroke.
The limbs: it may seem strange that cardiovascular disease can affect the limbs but narrowing of the blood vessels that supply the legs, causes a lack of blood flow and oxygen delivery to the working muscles. Aching legs or restless leg syndrome can result, with leg ulcers likely as the problem gets worse. It is also possible for a clot to form on the blood vessel in a limb, a condition known as a deep vein thrombosis. Sometimes this clot, or part of it, breaks off and travels elsewhere in the body. It stops when it blocks a smaller blood vessel. This often happens in the lungs, causing a pulmonary thrombosis.
Symptoms of heart disease typically include heavy or tight feelings within the chest. Intense pain follows that can be felt in the throat or left arm as well as in the chest itself. If pain of this type is experienced and does not subside within 20 minutes, you should be seen urgently by a doctor or paramedic.
Symptoms of a stroke normally arise suddenly and can vary depending on the artery affected. Symptoms can include paralysis or numbness of one side of the body, difficulties speaking or swallowing, and problems with vision, balance and coordination.
Symptoms of peripheral vascular disease include pain in the legs, ulcers (large sores that won’t heal) and even gangrene in the feet. This happens when the blood supply is so poor that the muscles in the feet die. Amputation is then the only treatment.
Diagnosing the disease
Unfortunately, cardiovascular disease is often not diagnosed until there are obvious symptoms. A sudden heart attack or stroke can be fatal. If you experience symptoms or think you may be at risk of cardiovascular disease, discuss this with your doctor. Early diagnosis can reduce your risk of a serious cardiovascular event.
Diagnosis of cardiovascular disease is usually based on symptoms, a physical examination and other tests, such as a chest x-ray, an electrocardiogram (ECG; where the electrical activity of the heart is monitored), or a coronary angiography. This is a very useful imaging technique in which a fine tube is used to view inside the arteries to detect narrowing.
Cardiovascular disease risk factors
Cardiovascular disease is associated with several well-known risk factors, some of which you can avoid and some you can’t.
Cardiovascular disease risk factors that you can avoid or minimise include:
- Being overweight and/or having a large waist circumference (being 'apple-shaped').
- Not getting much exercise or physical activity.
- High levels of LDL cholesterol.
- High triglycerides (usually caused by the build up of fats from eating a high-fat diet).
- Low HDL cholesterol.
- High blood pressure.
- Poor kidney function.
Cardiovascular disease risk factors that you cannot change include:
- Family history.
- Gender (being male increases the risk of cardiovascular disease).
- Ethnic background (ancestry from India, Pakistan, Bangladesh, or Sri Lanka increases the risk of cardiovascular disease).
The main thing you can do to avoid cardiovascular disease is to make lifestyle changes to reduce your risk factors. These changes include stopping smoking, taking more exercise and changing your diet.
Drug treatments can also help control the symptoms of cardiovascular disease. Medications include beta-blockers to control heart activity and reduce oxygen demand and diuretics to lower blood pressure. Statins are often used to control cholesterol levels and aspirin is commonly prescribed to help prevent blood clots.
In severe cases of cardiovascular disease, you may be advised to have surgery. This can either be an angioplasty, in which a small balloon or stent is inserted to open up a blocked vessel, or a coronary artery bypass. This is a major operation in which blood vessels from another site, usually the leg, are used to bypass the blocked artery in the heart.