Angina - Causes, Symptoms, Treatment
Angina (an-JI-nuh or AN-juh-nuh) is chest pain or discomfort that occurs when an area of your heart muscle doesn’t get enough oxygen-rich blood. Angina may feel like pressure or squeezing in your chest. The pain also may occur in your shoulders, arms, neck, jaw, or back. It can feel like indigestion. Angina itself isn’t a disease. Rather, it’s a symptom of an underlying heart problem.Angina can affect people in different ways and the symptoms may vary at different times. It is usually felt across the centre of the chest but may also be felt in either or both shoulders, the neck or jaw, down one or both arms and in the hands. Some people experience it in only one of these areas and not in the chest at all. Others, in particular people with diabetes, can get very little pain and may just complain of breathlessness.
There are three types of angina: stable, unstable and variant. Unstable angina is the most dangerous. It does not follow a pattern and can happen without physical exertion. It is does not go away with rest or medicine. It is a sign that you could have a heart attack soon.
Causes
If you have angina, one or more of your coronary arteries is usually narrowed. This causes a reduced blood supply to a part or parts of your heart muscle. The blood supply may be enough when you are resting. However, your heart muscle needs more blood and oxygen when it works harder. For example, when you walk fast or climb stairs, your heart rate increases to deliver the extra blood. If the extra blood that your heart needs during exertion cannot get pass the narrowed coronary arteries, the heart ‘complains’ with pain.
When tissue is denied adequate oxygen, it’s called ischemia. Angina is therefore usually caused by myocardial ischemia (inadequate oxygen in the heart muscle). This isn’t the same as myocardial infarction (heart attack). Infarction is the term for permanent cell death caused by prolonged and severe ischemia. In angina, the cells aren’t usually so starved of oxygen that they die. This is why rest or medication is usually effective in relieving the pain.
Symptoms
The symptoms of angina can include: pain or discomfort in the middle of the chest, pain in the neck and throat, jaw, one or both arms, stomach and more rarely between the shoulder blades, breathlessness or a choking feeling, sweating, feeling sick or exhausted. Many people with angina experience only some of these symptoms and mild angina may have no symptoms at all. Chest pain is the most common symptom of angina and is often described as a feeling of tightness or as a heavy weight on the chest.
Angina usually occurs during exertion, severe emotional stress, or after a heavy meal. During these periods, the heart muscle demands more blood oxygen than the narrowed coronary arteries can deliver. Angina typically lasts from 1 to 15 minutes and is relieved by rest or by placing a nitroglycerin tablet under the tongue. Nitroglycerin relaxes the blood vessels and lowers blood pressure. Both rest and nitroglycerin decrease the heart muscles demand for oxygen, thus relieving angina.
Treatment
Controlling the risk factors for angina pectoris, such as high blood pressure, cigarette smoking, high cholesterol levels, and excess weight is an essential part of treatment. The most common medication used to treat people with angina are nitrates (such as amyl nitrite or nitroglycerin) which help alleviate pain by widening the blood vessels, thereby allowing more blood flow to the heart muscle and decreasing the work load of the heart.
Medicines called nitrates are useful in preventing and reducing the frequency and intensity of episodes in patients with chronic angina. They work by relaxing and widening the blood vessels and allow more blood flow. Medicines called beta-blockers are taken to prevent and relieve angina by blocking (inhibiting) the effect of chemicals produced in the body called adrenaline and noradrenaline, on the heart.
