Untitled Essay, Research Paper
QUESTION: What is Angina? And
what is the cure?
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 diseas refers to
those syndromes caused by blockage to 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 rmovement, 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 syndromes.
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.
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