Discomfort in the chest that can range from mild discomfort to severe pain is called angina. Although chest pain can have many origins, true angina is a symptom of inadequate blood and oxygen supply to the heart, a condition most often due to plaque in the arteries (also called ischemic or coronary heart disease). The heart requires a steady supply of oxygen and nutrients from arteries on the surface of the heart muscle called coronary arteries. When deposits (plaques) build up within the arteries, the condition is called coronary atherosclerosis (also known as coronary heart disease or ischemic heart disease). These plaques contain fats and inflammatory cells, and occur more frequently in smokers, older adults, males, and people with diabetes, high blood pressure, and high cholesterol. The plaques narrow the coronary arteries, reducing the arteries' ability to supply the heart with blood. When the heart does not receive enough oxygen and nutrients, angina results.
Most people experience angina when the heart's demand for oxygen increases; such as during exercise, while walking up stairs or hills, during stressful situations, or after eating a large meal.
However, a person can also experience angina while at rest, which may reflect a very serious form of the condition, or may be a warning sign of an impending heart attack.
Angina is more common in men than in women.
About 70% of people who have angina are men. The typical angina patient is a man older than age 50 or a woman older than age 60.
There are two main types of angina: stable angina and unstable angina. Stable angina occurs fairly predictably, and is usually triggered by certain activities or situations. Unstable angina is a worsening pattern of chest pain that occurs more frequently, more severely, and/or at lower levels of activity. If you are suffering from chest pain that is new (less than two months), or begins to occur more frequently, more severely, or at lower levels of activity, you may have unstable angina. This can be a sign of an impending heart attack, and should be treated as a medical emergency. You can develop unstable angina suddenly, or you may feel a gradual worsening of your symptoms over days to weeks. Stable angina can develop into unstable angina; however, unstable angina can also occur without stable angina preceding it.
If you have been diagnosed with stable angina and you notice that the attacks are increasing in frequency and severity, or that they occur while you are resting or after exerting yourself less strenuously than normal, this may signal the onset of unstable angina or an impending heart attack. True unstable angina is a medical emergency.
It can be difficult to tell the difference between angina and a heart attack. Pain from a heart attack is usually more severe, and usually lasts longer (for example, longer than 10-15 minutes). However, angina can feel very similar to a heart attack. Angina is heart pain that results from inadequate blood and oxygen flow to an area of heart muscle. While painful, angina does not permanently damage the heart muscle. A heart attack, on the other hand, does actual damage to a part of the heart muscle as a result of inadequate blood and oxygen flow. How much heart muscle is damaged by a heart attack depends on the size of the artery supplying the affected area of the heart and how quickly the heart attack is treated.
You can lower your risk of a heart attack with diet, exercise, medications, stopping smoking, and maintaining control of blood pressure, cholesterol, and diabetes. However, the risk can never be eliminated, so treat angina as a serious reminder to take care of your health.
Medications are available to treat angina.
When angina occurs, certain medications can be taken to dilate the heart arteries temporarily, allowing increased blood and oxygen flow to the heart. Other medications can be taken regularly to reduce or relieve the symptoms of angina before they even occur.
Whatever type of angina you have, you should take steps to reduce your heart disease risk factors by maintaining a proper weight, exercising regularly, and lowering cholesterol levels. If you are a smoker, it is essential that you quit. Your doctor may also recommend taking aspirin regularly. In many cases, lifestyle changes, medications, and treating underlying conditions such as high blood pressure can be enough to ease stable angina without need for further procedures or surgery. Importantly, these measures also reduce the risk of future heart attacks and the risk of death from heart disease.
Procedures such as angioplasty (opening the narrowed part of the artery with a balloon) and coronary artery bypass grafting (bypassing the narrowed part of the artery with surgery) often can reduce angina that cannot be controlled by these measures.
Stable angina is caused by partial obstruction of the blood vessels of the heart (coronary arteries)Figure 01. Deposits (plaques) in the walls of the coronary arteries narrow the area inside the artery available for carrying blood. This reduces the capacity of the artery to supply the heart muscle with oxygen and nutrients.
Angina occurs when the heart's need for oxygen is greater than what the blood vessels are able to supply. Exercise, cold weather, stressful situations, and large meals can all trigger an attack.
Unstable angina is believed to occur when a plaque in a coronary artery splits or breaks open (ruptures), releasing materials contained within the plaque into the bloodstream. The causes of plaque rupture are not well understood. When a plaque ruptures, clot-forming cells (platelets) and inflammatory cells gather at the site to attempt to repair the damage, similar to what occurs when you cut your skin. These cells may form a blood clot and release chemicals that narrow the blood vessel further. The clot and the narrowing of the blood vessel (spasm) may act to partially or completely block blood flow very quickly--within hours or even minutes. This sudden decrease in blood flow often causes severe, prolonged pain, and may lead to a heart attack. If you suspect unstable angina, this is a medical emergency, and you should immediately go to a hospital via ambulance.
Figure 01. A normal and clogged coronary artery
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