Angina
Definition
Angina is pain, "discomfort," or pressure localized in the chest that is caused by an insufficient supply of blood (ischemia) to the heart muscle. It is also sometimes characterized by a feeling of choking, suffocation, or crushing heaviness. This condition is also called angina pectoris.
Description
Often
described as a muscle spasm and choking sensation, the term "angina" is
used primarily to describe chest (thoracic) pain originating from
insufficient oxygen to the heart muscle. An episode of angina is not an
actual heart attack,
but rather pain that results from the heart muscle temporarily
receiving too little blood. This temporary condition may be the result
of demanding activities such as exercise
and does not necessarily indicate that the heart muscle is experiencing
permanent damage. In fact, episodes of angina seldom cause permanent
damage to heart muscle.
Angina can be subdivided further into two categories: angina of effort and variant angina.
Angina of effort
Angina of effort is a common disorder caused by the narrowing of the arteries (atherosclerosis)
that supply oxygen-rich blood to the heart muscle. In the case of
angina of effort, the heart (coronary) arteries can provide the heart
muscle (myocardium) adequate blood during rest but not during periods of
exercise, stress,
or excitement—any of which may precipitate pain. The pain is relieved
by resting or by administering nitroglycerin, a medication that reduces
ischemia of the heart. Patients with angina of effort have an increased
risk of heart attack (myocardial infarction).
Variant angina
Variant
angina is uncommon and occurs independently of atherosclerosis which
may, however, be present as an incidental finding. Variant angina occurs
at rest and is not related to excessive work by the heart muscle.
Research indicates that variant angina is caused by coronary artery
muscle spasm of insufficient duration or intensity to cause an actual
heart attack.
Causes and symptoms
Angina
causes a pressing pain or sensation of heaviness, usually in the chest
area under the breast bone (sternum). It occasionally is experienced in
the shoulder, arm, neck, or jaw regions. Because episodes of angina
occur when the heart's need for oxygen increases beyond the oxygen
available from the blood nourishing the heart, the condition is often
precipitated by physical exertion. In most cases, the symptoms are
relieved within a few minutes by resting or by taking prescribed angina
medications. Emotional stress, extreme temperatures, heavy meals,
cigarette smoking, and alcohol can also cause or contribute to an episode of angina.
Diagnosis
Physicians
can usually diagnose angina based on the patient's symptoms and the
precipitating factors. However, other diagnostic testing is often
required to confirm or rule out angina, or to determine the severity of
the underlying heart disease.
Electrocardiogram (ecg)
An
electrocardiogram is a test that records electrical impulses from the
heart. The resulting graph of electrical activity can show if the heart
muscle isn't functioning properly as a result of a lack of oxygen.
Electrocardiograms are also useful in investigating other possible
abnormal features of the heart.
Stress test
For
many individuals with angina, the results of an electrocardiogram while
at rest will not show any abnormalities. Because the symptoms of angina
occur during stress, the functioning of the heart may need to be
evaluated under the physical stress of exercise. The stress test
records information from the electrocardiogram before, during, and
after exercise in search of stress-related abnormalities. Blood pressure
is also measured during the stress test and symptoms are noted. A more
involved and complex stress test (for example, thallium scanning) may be
used in some cases to picture the blood flow in the heart muscle during
the most intense time of exercise and after rest.
Angiogram
The
angiogram, which is basically an x ray of the coronary artery, has been
noted to be the most accurate diagnostic test to indicate the presence
and extent of coronary disease. In this procedure, a long, thin,
flexible tube (catheter) is maneuvered into an artery located in the
forearm or groin. This catheter is passed further through the artery
into one of the two major coronary arteries. A dye is injected at that
time to help the x rays "see" the heart and arteries more clearly. Many
brief x rays are made to create a "movie" of blood flowing through the
coronary arteries, which will reveal any possible narrowing that causes a
decrease in blood flow to the heart muscle and associated symptoms of
angina.
Treatment
Conservative treatment
Artery
disease causing angina is addressed initially by controlling existing
factors placing the individual at risk. These risk factors include
cigarette smoking, high blood pressure, high cholesterol levels, and obesity.
Angina is often controlled by medication, most commonly with
nitroglycerin. This drug relieves symptoms of angina by increasing the
diameter of the blood vessels carrying blood to the heart muscle.
Nitroglycerin is taken whenever discomfort occurs or is expected. It may
be taken by mouth by placing the tablet under the tongue or
transdermally by placing a medicated patch directly on the skin. In
addition, beta blockers or calcium channel blockers may be prescribed to also decrease the demand on the heart by decreasing the rate and workload of the heart.
Surgical treatment
When
conservative treatments are not effective in the reduction of angina
pain and the risk of heart attack remains high, physicians may recommend
angioplasty
or surgery. Coronary artery bypass surgery is an operation in which a
blood vessel (often a long vein surgically removed from the leg) is
grafted onto the blocked artery to bypass the blocked portion. This
newly formed pathway allows blood to flow adequately to the heart
muscle.
Key terms
Ischemia — Decreased blood supply to an organ or body part, often resulting in pain.
Myocardial infarction
— A blockage of a coronary artery that cuts off the blood supply to
part of the heart. In most cases, the blockage is caused by fatty
deposits.
Myocardium — The thick middle layer of the heart that forms the bulk of the heart wall and contracts as the organ beats.
Another
procedure used to improve blood flow to the heart is balloon
angioplasty. In this procedure, the physician inserts a catheter with a
tiny balloon at the end into a forearm or groin artery. The catheter is
then threaded up into the coronary arteries and the balloon is inflated
to open the vessel in narrowed sections. Other techniques using laser
and mechanical devices are being developed and applied, also by means of
catheters.
Alternative treatment
During
an angina episode, relief has been noted by applying massage or
kinesiological methods, but these techniques are not standard
recommendations by physicians. For example, one technique places the
palm and fingers of either hand on the forehead while simultaneously
firmly massaging the sternum (breast bone) up and down its entire length
using the other hand. This is followed by additional massaging by the
fingertip and thumb next to the sternum, on each side.
Once
the angina has subsided, the cause should be determined and treated.
Atherosclerosis, a major associated cause, requires diet and lifestyle
adjustments, primarily including regular exercise, reduction of dietary
sugar and saturated fats, and increase of dietary fiber. Both
conventional and alternative medicine agree that increasing exercise and
improving diet are important steps to reduce high cholesterol levels.
Alternative medicine has proposed specific cholesterol-lowering
treatments, with several gaining the attention and interest of the
public. One of the most recent popular treatments is garlic (Allium sativum).
Some studies have shown that adequate dosages of garlic can reduce
total cholesterol by about 10%, LDL (bad) cholesterol by 15%, and raise
HDL (good) cholesterol by 10%. Other studies have not shown significant
benefit. Although its effect on cholesterol is not as great as that
achieved by medications, garlic may possibly be of benefit in relatively
mild cases of high cholesterol, without causing the side effects
associated with cholesterol-reducing drugs. Other herbal remedies that may help lower cholesterol include alfalfa (Medicago sativa), fenugreek (Trigonella foenum-graecum), Asian ginseng (Panax ginseng), and tumeric (Curcuma longa).
Antioxidants,
including vitamin A (beta carotene), vitamin C, vitamin E, and
selenium, can limit the oxidative damage to the walls of blood vessels
that may be a precursor of atherosclerotic plaque formation.
Prognosis
The
prognosis for a patient with angina depends on its origin, type,
severity, and the general health of the individual. A person who has
angina has the best prognosis if he or she seeks prompt medical
attention and learns the pattern of his or her angina, such as what
causes the attacks, what they feel like, how long episodes usually last,
and whether medication relieves the attacks. If patterns of the
symptoms change significantly, or if symptoms resemble those of a heart
attack, medical help should be sought immediately.
Prevention
In
most cases, the best prevention involves changing one's habits to avoid
bringing on attacks of angina. If blood pressure medication has been
prescribed, compliance is a necessity and should be a priority as well.
Many healthcare professionals—including physicians, dietitians, and
nurses—can provide valuable advice on proper diet, weight control, blood
cholesterol levels, and blood pressure. These professionals also offer
suggestions about current treatments and information to help stop
smoking. In general, the majority of those with angina adjust their
lives to minimize episodes of angina, by taking necessary precautions
and using medications if recommended and necessary. Coronary artery disease is the underlying problem that should be addressed.
Resources
Organizations
National Heart, Lung and Blood Institute. P.O. Box 30105, Bethesda, MD 20824-0105. (301) 251-1222. http://www.nhlbi.nih.gov.
Other
"Angina." Healthtouch Online Page. Sepember 1997. [cited May 21, 1998]. http://www.healthtouch.com.
Citations:
For Gale Encyclopedia of Medicine:angina. (n.d.) Gale Encyclopedia of Medicine. (2008). Retrieved October 14 2012 from http://medical-dictionary.thefreedictionary.com/anginaFor Dorland's Medical Dictionary:angina. (n.d.) Dorland's Medical Dictionary for Health Consumers. (2007). Retrieved October 14 2012 from http://medical-dictionary.thefreedictionary.com/anginaFor The American Heritage® Medical Dictionary:angina. (n.d.) The American Heritage® Medical Dictionary. (2007). Retrieved October 14 2012 from http://medical-dictionary.thefreedictionary.com/anginaFor Mosby's Medical Dictionary:angina. (n.d.) Mosby's Medical Dictionary, 8th edition. (2009). Retrieved October 14 2012 from http://medical-dictionary.thefreedictionary.com/anginaFor Miller-Keane Encyclopedia:angina. (n.d.) Miller-Keane Encyclopedia and Dictionary of Medicine, Nursing, and Allied Health, Seventh Edition. (2003). Retrieved October 14 2012 from http://medical-dictionary.thefreedictionary.com/anginaFor Dictionary of Complementary and Alternative Medicine:angina. (n.d.) Jonas: Mosby's Dictionary of Complementary and Alternative Medicine. (2005). Retrieved October 14 2012 from http://medical-dictionary.thefreedictionary.com/anginaFor Dental Dictionary:angina. (n.d.) Mosby's Dental Dictionary, 2nd edition. (2008). Retrieved October 14 2012 from http://medical-dictionary.thefreedictionary.com/anginaFor McGraw-Hill Concise Dictionary of Modern Medicine:angina. (n.d.) McGraw-Hill Concise Dictionary of Modern Medicine. (2002). Retrieved October 14 2012 from http://medical-dictionary.thefreedictionary.com/angina |
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