Angina is chest pain or discomfort experienced when the blood flow to the heart muscle is gradually or suddenly reduced. Oxygen is carried in the blood stream and the heart requires oxygen to work and survive. If there is not an adequate supply of blood to the heart, angina occurs.
The heart is responsible for pumping blood enriched with nutrient and oxygen throughout the body. Your heart also requires nutrients and oxygen to do its job. This is accomplished through a system of vessels known as coronary arteries. When the coronary arteries are healthy, the heart receives the appropriate amount of blood flow to meet its needs.
Coronary artery disease (atherosclerosis) is the narrowing or blockage of the arteries that supply blood to the heart. Coronary artery disease is the most common cause of angina. Fatty deposits which are called as plaques build up within the arteries and cause narrowing, much like sludge building in a pipe. This narrowing significantly reduces circulation to the heart and results in ischemia, or lack of oxygen.
The discomfort of angina generally occurs with times of increased physical activity. It is quite simply an issue of low supply to the heart. When you are more active, your heart must work harder and needs more blood flow to function normally. During times of rest, when the oxygen needs are less, angina may not occur. Rest often frequently relieves chest pain and discomfort.
- Stable Angina. The pain associated with stable angina is generally predictable and occurs with physical activities, such as walking or exercising. Physical exertion means the heart requires a greater supply of blood, but arteries that are narrowed cannot deliver the amount required. Other triggers include smoking, stress and eating a large meal. All of these factors “steal” blood supply from the heart and can cause an episode of angina.
- Unstable Angina. When the plaques or fatty deposits in an artery rupture or the formation of a clot occurs, sudden interruption of the blood flow to the heart will occur. The pain of unstable angina is severe and occurs suddenly. It tends to become worse with time and resting does not alleviate it, nor do the use of angina medications. This type of angina demands immediate emergency medical treatment as it can lead to a heart attack.
- Prinzmetal’s Angina. Prinzmetal’s angina is also known as “Variant” angina. It is caused by spasms within the coronary artery system. When these spasms occur, blood flow is reduced and chest pain or discomfort is experienced. Symptoms usually occur at night or early morning hours. Risk factors include smoking, exposure to cold temperatures and cocaine use.
- Microvascular Angina. In contrast to the narrow arteries of typical CAD, microvascular disease affects the very small arteries that supply the heart. It is more common in people affected with high blood pressure, those with diabetes and women after menopause. Symptoms are generally experienced during everyday tasks or periods of emotional stress and accompanied by excessive fatigue and weakness. Sleep difficulties and excessive sweating are also common.