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Angina pectoris is the occurrence
of chest pain resulting from
inadequate oxygen delivery to the
heart muscle. The decrease of
blood supply to the heart may also
results in an obstruction of certain
blood vessels, known as cardiac
ischemia.
This
form of angina occurs most often
after exercise, but can also be
precipitated by emotional stress, a
large meal, or cold weather.[1]
There are two other forms of angina:
Prinzmetal's, or Variant Angina, and
coronary artery spasm induced by magnesium deficiency. For the
purpose of this article all
information will pertain to "angina
pectoris." |
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Angina is a result of coronary
artery disease. Coronary artery
disease is narrowing of the lumen of
the vessels that supply blood (and
oxygen) to the heart muscle. As the
work load on the heart increases the
demand for oxygen in the cells
increases. When the lumen is
narrowed by greater than 50% there
will not be sufficient delivery of
oxygen so the muscle cells will
become ischemic and the individual
will experience pain.
The pain is a result of both the
ischemia and building up of
metabolites from producing energy
without oxygen (anaerobic
metabolism). Individuals with
coronary artery disease will often
have high cholesterol and
triglycerides levels, high blood pressure,
atherosclerosis, and high fasting
blood sugar. Angina can also be
caused by diseases that increase the
work load on the heart (aortic
stenos is, COPD, etc), cocaine
overdose, and coronary embolism.[2]
The treatment section of this
article will focus on angina caused
by coronary artery disease.
The pain of angina occurs in
episodes that last just a few
minutes. Individuals can describe
the episode in a range of ways.
Most complaints arise from either a vague ache
or crushing pain. The
pain is usually felt over the breast
bone, but may radiate to the left
shoulder/arm, jaw, teeth, right arm,
and abdomen.
Angina is most often precipitated by
physical exertion that increases the
work load on the heart. It is worse
when the exertion follows a meal and
cold weather. It is usually relieved
by rest and can always be relieved
by sublingual (under the tongue)
nitroglycerin.
During the episode, heart rate
and blood pressure may
increase, there may be an extra
heart sound (changes in heart
sounds), and palpation of the cardiac
border, which may reveal further irregularities.[4]
Many individuals will not know of any
underlying heart disease until they
experience their first episode of angina.
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Angina affects 6.8 million
Americans.
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Each year there is an estimated
400,000 new cases.
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Angina affects women greater
than men in each age and race
category.
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Coronary artery disease is the cause
of 1 in 5 deaths each year in the
US.
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There will be an estimated 1.2
million new and recurrent cases of
angina and myocardial
infarction (heart attack) each year,
and 42% will die.[3]
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