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Angina (angina
pectoris - Latin for squeezing of the chest) is the chest discomfort that occurs
when the blood oxygen supply to an area of the heart muscle does not meet the
demand. In most cases, the lack of blood supply is due to a narrowing of the
coronary arteries as a result of arteriosclerosis (see below). Angina is usually
felt as a squeezing, pressure, heaviness, tightening, or aching across the
chest, particularly behind the breastbone. This pain often radiates to the neck,
jaw, arms, back, or even the teeth. Patients may also complain of indigestion,
heartburn, weakness, sweating, nausea, cramping, and shortness of breath. Angina
usually occurs during exertion, severe emotional stress, or after a heavy meal.
During these periods, the heart muscle demands more blood oxygen than the
narrowed coronary arteries can deliver. Angina typically lasts from 1 to 15
minutes and is relieved by rest or by placing a nitroglycerin tablet under the
tongue. Nitroglycerin relaxes the blood vessels and lowers blood pressure. Both
resting and nitroglycerin decrease the heart muscles demand for oxygen, thus
relieving angina.
Blood is supplied to the
body via the heart. The heart itself also needs blood. . There are two main
arteries - the left and right coronary arteries. These divide many times
supplying oxygenated blood to all the walls of the heart.
The coronary arteries
can, over time, narrow by a build-up of fatty material in the walls. The
constriction of the arteries can make it harder for oxygenated blood to reach
the heart muscle. The problem is exacerbated when heavy demands are made of the
heart such as when exercising. The shortfall of oxygenated blood when there is a
heavy demand causes the tightness or heavyness of the chest that sufferers
report. This is Angina. Angina differs from a heart attack in that the arteries
are not actually blocked or clotted, but simply that the blood flow is severely
restricted.
Types of Angina :
Stable Angina - so named
when an attack is predictable i.e. after a certain amount of
exercise.
Unstable Angina - when attacks are unpredictable and occur at
any time - even when resting.
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