Angina pectoris is the medical term for chest pain or discomfort due to
coronary heart disease. Angina is a symptom of a condition called myocardial
ischemia. It occurs when the heart muscle (myocardium) doesn't get
as much blood (hence as much oxygen) as it needs. This usually happens
because one or more of the heart's arteries (blood vessels that supply
blood to the heart muscle) is narrowed or blocked. Insufficient blood
supply is called ischemia.