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Introduction Angina is not a disease. It is a pain, a symptom of another disease, the very common condition called atherosclerosis, which affects many arteries. In this case, the arteries concerned are the coronary arteries of the heart. These two arteries and their branches supply the very active muscle of the heart with the blood it needs to keep beating. If they can provide enough blood so that the heart muscle gets the amount of glucose fuel and oxygen it need for its energy supply, the heart goes on beating painlessly. But if the coronary arteries have been narrowed and cant get the blood to the heart muscle fast enough, abnormal levels of substances collect in the muscles to the point of causing pain. This pain is angina. The full name for the symptom is angina pectoris. This is Latin for pain in the chest. The symptom is far more common in men than in pre-menopausal women. After the menopause, women who are not on HRT are as likely to get angina as men are as they no longer have the same hormone protection.
Causes Angina occurs when arteriosclerosis has caused so much narrowing of the coronary arteries that they are not able to supply enough blood to the heart muscle during exercise. In most cases angina doesnt occur while youre at rest. But the stronger or more prolonged the exertion, the greater is the amount of blood that the heart needs. Healthy coronary arteries can pass enough blood to allow the heart to reach its maximum output without pain. But narrowing of the coronary arteries will always mean that there is a limit to the rate at which blood can get to the heart muscle, in spite of its needs. Angina symptoms develop when the heart demands more oxygen than can be supplied or when the supply drops below demand.
Diagnosis Chest pain that is always related to exertion is a fairly sure indication of angina. The diagnosis can be confirmed by a special test called an electrocardiogram (ECG) which produces a tracing of the electrical activity in the heart.
Treatment The drug glyceryl trinitrate (nitroglycerine) is highly effective in controlling the pain of angina. You can take it as a tablet that dissolves under your tongue, and the pain is usually relieved in two to three minutes. The drug is also available in skin patches (transdermal patches) and as a spray (again for under the tongue), and all forms are available from a pharmacy without prescription. Nitrates have a powerful action in widening (dilating) arteries, including the coronary arteries, thus improving the blood supply to the heart muscle. Note that you should not take Viagra (sildenafil) if you take glyceryl trinitrate. Taking low-dose aspirin daily helps prevent blood clotting and reduces the risk of heart attack. Mild or moderate angina may need further treatment by drugs such as beta blockers (eg Antenolol) or calcium-channel blockers (eg Nifedipine). Potassium-channel activator drugs also help to widen the coronary arteries. These drugs can slow the force of contraction of the heart and dilate the coronary arteries, thus reducing the demand for oxygen and increasing supply to the heart. For unstable angina the treatment is a daily 300 mg dose of aspirin, and injectable anticoagulants such as Heparin are administered in hospital. Nitrates and beta blockers may also be necessary.
An effective treatment for angina is to widen the narrowed coronary arteries by a procedure called coronary angioplasty. This is done using a small-gauge tube called a balloon catheter. This has a sausage-shaped balloon segment near one end and is pushed into the narrowed part of the artery. The balloon is then inflated to widen the narrowed artery. The results are excellent, but the procedure may have to be repeated. In other cases, a bypass operation may be considered more suitable. Segments of vein are used to provide a new channel by which the blood can be shunted past the blocked part of the artery. Some surgeons prefer to connect a local artery from the chest wall to the narrowed coronary beyond the point of the block. Complications Unstable angina is a severe and dangerous form of angina pectoris that is due to the breakdown of a plaque of atherosclerosis in the coronary arteries and the formation of a blood clot (thrombosis) on the raw surface. There may also be tightening of the coronary artery (spasm). Pain becomes more frequent and prolonged, and may occur at rest. It is no longer possible to predict the onset of pain in relation to a known amount of exertion, and the risk of a heart attack is high. Unstable angina requires admission to hospital in order to provide supportive care and pain relief during an acute attack and to prevent a heart attack. Prevention Keeping within your exertion limits can prevent the frequency and severity of angina attacks. If you already have angina it is not too late to try to improve the situation by trying to get as much exercise as you safely can. A daily low dose of aspirin (e.g. 75-150mg) is recommended, and perhaps a lipid-lowering drug considered to reduce the risk of attacks.
Definition The pain of angina is related to the demands made on the heart, most commonly for the performance of physical exercise, but also to cope with emotional reactions. The pain usually comes on after a fixed amount of exertion, such as walking a particular distance. Angina pain may be of very variable severity, even in the same person, and may be affected by factors such as cold weather, a change of temperature as when going outside from a warm house, the strength of the wind, state of mind, or the length of time since a meal. The pain may be so mild as to be hardly a pain but more a feeling of uneasiness or pressure in the chest; or it may be so severe that it stops you moving. It often causes breathlessness and belching, and when the exertion ceases, the angina settles. It is quite common for angina to remain at a fairly constant level of severity for years. In such cases the affected person will know exactly how far he or she can walk before the pain starts. But with other sufferers, all the features of angina may vary. In some cases the angina may be absent for weeks, months or even years. In others it may increase in frequency and severity until there is severe disability or death.
Glossary Blood Blood supplies oxygen to the body and removes carbon dioxide. It is pumped around the body by the heart.
Heart The heart is a muscular organ that pumps blood around the body.
Oxygen Oxygen is an odourless, colourless gas that makes up about 20% of the air we breathe.
Artery Arteries are blood vessels that carry blood from the heart to the rest of the body. Vein Veins are blood vessels that carry blood from the rest of the body back to the heart.
Coronary angioplasty Coronary angioplasty is surgery to open up arteries in the heart that have been blocked or narrowed by fatty deposits.
Urinary catheterisation Urinary catheterisation involves placing a catheter (a thin, hollow tube usually made of rubber) into the bladder to inject or remove fluid. G
Glucose Glucose (or dextrose) is a type of sugar that is used by the body to produce energy.
HRT Hormone replacement therapy or HRT involves giving hormones to women when the menopause starts, to replace those that the body no longer produces.
Acute Acute means occuring suddenly or over a short period of time.
Catheter A catheter is a thin, hollow tube usually made of rubber that is placed into the bladder to inject or remove fluid.
Angina Angina is chest pain caused by a reduced flow of blood to the heart, typically resulting from heart disease.
Beta blocker Beta blockers are drugs that lower blood pressure and slow the heart rate, by reducing the amount of oxygen that the blood needs.
Bypass A bypass is when the flow of blood or other fluid is redirected, permanently because of a blockage in the body, or temporarily during an operation.
Pain Pain is an unpleasant physical or emotional feeling that your body produces as a warning sign that it has been damaged.
Onset The onset is the beginning or early stages of a condition or disease.
ECG An ECG (electrocardiogram) is a test that measures electrical activity in the heart, and is used to identify heart problems.
Anticoagulant Anticoagulant is a substance that stops blood from clotting (prevents coagulation). For example warfarin.
Dose Dose is a measured quantity of a medicine to be taken at any one time, such as a specified amount of medication
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