Angina

Angina pectoris, commonly known as angina, is the sensation of chest pain, pressure, or squeezing, often due to not enough blood flow to the heart muscle as a result of obstruction or spasm of the Coronary arteries. The term derives from the Latin angere ("to strangle") and pectus ("chest"), and can therefore be translated as "a strangling feeling in the chest".

While angina pectoris can occur due to

• anemia,
• abnormal heart rhythms and
• heart failure

Its main cause is coronary artery disease, an Atherosclerotic process affecting the arteries feeding the heart.

Stable angina

Also known as 'effort angina', this refers to the classic type of angina related to Myocardial ischemia.

A typical presentation of stable angina is that of chest discomfort and associated symptoms precipitated by some activity (running, walking, etc.) with minimal or non-existent symptoms at rest or after administration of sublingual nitroglycerin.

Symptoms typically abate several minutes after activity and recur when activity resumes. In this way, stable angina may be thought of as being similar to intermittent claudication symptoms. Other recognized precipitants of stable angina include cold weather, heavy meals, and emotional stress.

Unstable angina

Unstable angina (UA) (also "crescendo angina"; this is a form of acute coronary syndrome) is defined as angina pectoris that changes or worsens.[5]

It has at least one of these three features:

1. it occurs at rest (or with minimal exertion), usually lasting more than 10 minutes
2. it is severe and of new onset (i.e., within the prior 4–6 weeks)
3. it occurs with a crescendo pattern (i.e., distinctly more severe, prolonged, or frequent than before).

UA may occur unpredictably at rest, which may be a serious indicator of an impending heart attack. What differentiates stable angina from unstable angina (other than symptoms) is the Pathophysiology of the Atherosclerosis. The pathophysiology of unstable angina is the reduction of coronary flow due to transient platelet aggregation on apparently normal endothelium, coronary artery spasms, or coronary thrombosis.

The process starts with atherosclerosis, progresses through inflammation to yield an active unstable plaque, which undergoes thrombosis and results in acute Myocardial ischemia, which, if not reversed, results in cell Necrosis (Infarction).