Reviewed by Michael Fuller, MDAngina Pectoris ("Angina") is a recurring pain or discomfort in the chest that happens when some part of the heart does not receive enough blood. Angina is a symptom suggesting coronary artery disease (CAD), which occurs when vessels that carry blood to the heart become narrowed and blocked due to atherosclerosis. Angina feels like a pressing or squeezing pain, usually in the chest under the breastbone, but sometimes the sensation is felt in the shoulders, arms, neck, jaws, or back. Angina is usually precipitated by physical exertion. It may be relieved within a few minutes by resting or by taking prescribed medication.
Risk factors for coronary artery disease include: family history, hypertension, increased cholesterol, smoking, diabetes, male gender, and advancing age.
There are several types of angina:
"Stable" angina, the most common type of angina, often recurs in a regular, predictable pattern. A specific stimulus provokes the angina.
"Unstable” angina may first appear as new onset angina, a very severe episode of angina, or as frequently recurring bouts of angina that increase in frequency or severity. Angina that occurs at rest also falls into this category. The term "unstable angina" is also used when symptoms suggest a heart attack but hospital tests do not support that diagnosis.
Prinzmetal's or variant angina. This type is rare and is caused by vasospasm, contraction of the musculature surrounding the coronary arteries that narrows these vessels and lessens the flow of blood to the heart.
Microvascular angina. Patients with this condition experience chest pain but have no apparent coronary artery blockages. Microvascular angina can be treated with some of the same medications used for angina pectoris.Episodes of angina occur when the heart's need for oxygen increases beyond the oxygen available from the blood nourishing the heart. Unstable angina may occur when there is an existing narrowing of the artery by a cholesterol plaque and thrombosis (clot) occurs on top of the plaque. Thrombosis is caused by thrombin activation and platelet aggregation– and we will see below that therapy can be aimed at these two processes. Physical exertion is the most common trigger for angina. Other triggers include: emotional stress, extreme cold or heat, heavy meals, alcohol, drugs (cocaine), cigarette smoking or medical conditions such as severe and uncontrolled high blood pressure, thyroid disorders, diabetes and anemia.
