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Angina refers to the pain arising from lack of adequate
blood supply to the heart muscle. Typically, it is a
crushing pain behind the breastbone in the center of the
chest, brought on by exertion and relieved by rest. It may
at times radiate to or arise in the left arm, neck, jaw,
left chest, or back. It is frequently accompanied by
sweating, palpitations of the heart, and generally lasts a
matter of minutes. Similar pain syndromes may be caused by
other diseases, including esophagitis, gall bladder
disease, ulcers, and others.
Diagnosis of angina begins with the recognition of the
consistent symptoms. Often an exercise test with
radioactive thallium is performed if the diagnosis is in
question, and sometimes even a cardiac catheterization is
done if the outcome is felt necessary to make management
decisions. This is a complex area which requires careful
judgment by physician and patient.
Angina is a manifestation of coronary artery disease, the
same disease leading to heart attacks. Coronary artery
disease refers to those syndromes caused by blockage of the
flow of blood in those arteries supplying the heart muscle
itself, i.e., the coronary arteries. Like any other organ,
the heart requires a steady flow of oxygen and nutrients to
provide energy for movement, and to maintain the delicate
balance of chemicals which allow for the careful electrical
rhythm control of the heart beat. Unlike some other organs,
the heart can survive only a matter of minutes without
these nutrients, and the rest of the body can survive only
minutes without the heart-thus the critical nature of these
Causes of blockage range from congenital tissue strands
within or over the arteries to spasms of the muscular coat
of the arteries themselves. By far the most common cause,
however, is the deposition of plaques of cholesterol,
platelets and other substances within the arterial walls.
Sometimes the buildup is very gradual, but in other cases
the buildup is suddenly increased as a chunk of matter
breaks off and suddenly blocks the already narrowed opening.
Certain factors seem to favor the buildup of these plaques.
A strong family history of heart attacks is a definite risk
factor, reflecting some metabolic derangement in either
cholesterol handling or some other factor. Being male, for
reasons probably related to the protective effects of some
female hormones, is also a relative risk. Cigarette smoking
and high blood pressure are definite risks, both reversible
in most cases. Risk also increases with age. Elevated blood
cholesterol levels (both total and low density types) are
risks, whereas the high density cholesterol level is a risk
only if it is reduced. Possible, but less well-defined
factors include certain intense and hostile or
time-pressured personality types (so-called type A),
inactive lifestyle, and high cholesterol diets.
Medications are increasingly effective for symptom control,
as well as prevention of complications. The oldest and most
common agents are the nitrates, derivatives of
nitroglycerine. They include nitroglycerine, isosorbide,
and similar agents. Newer forms include long acting oral
agents, plus skin patches which release a small amount
through the skin into the bloodstream over a full day. They
act by reducing the burden of blood returning to the heart
from the veins and also by dilating the coronary arteries
themselves. Nitrates are highly effective for relief and
prevention of angina, and sometimes for limiting the size
of a heart attack. Used both for treatment of symptoms as
well as prevention of anticipated symptoms, nitrates are
considered by many to be the mainstay of medical therapy
for angina.
The second group of drugs are called "beta blockers" for
their ability to block the activity of the beta receptors
of the nervous system. These receptors cause actions such
as blood pressure elevation, rapid heart rate, and forceful
heart contractions. When these actions are reduced, the
heart needs less blood, and thus angina may be reduced.
The newest group of drugs for angina is called the calcium
channel blockers. Calcium channels refer to the areas of
the membranes of heart and other cells where calcium flows
in and out, reacting with other chemicals to modulate the
force and rate of contractions. In the heart, they can
reduce the force and rate of contractions and electrical
excitability, thereby having a calming effect on the heart.
Although their final place in heart disease remains to be
seen, they promise to play an increasingly important role.
When medications are unsuccessful, or if there is concern
about an impending or potential heart attack, coronary
bypass surgery is highly successful in reducing symptoms.
Whether or not it prolongs survival is questionable for
most patients.
Angina which is new or somehow different from previous
episodes in any way is termed unstable angina. It is
considered a medical emergency, and requires urgent
attention. Research is active, and careful medical
follow-up is important.



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