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Facts About Angina
What is angina?
Angina pectoris ("angina") is a recurring pain or discomfort in the chest that happens when some part
of the heart does not receive enough blood. It is a common symptom of coronary heart disease (CHD), which
occurs when vessels that carry blood to the heart become narrowed and blocked due to atherosclerosis
Angina feels like a pressing or squeezing pain, usually in the chest under the breast bone, but sometimes in the
shoulders, arms, neck, jaws, or back. Angina is usually precipitated by exertion. It is usually relieved within a few
minutes by resting or by taking prescribed angina medicine.
What brings on angina?
Episodes of angina occur when the heart's need for oxygen increases beyond the oxygen available from the blood
nourishing the heart. Physical exertion is the most common trigger for angina. Other triggers can be emotional
stress, extreme cold or heat, heavy meals, alcohol, and cigarette smoking.
Does angina mean a heart attack is about to happen?
An episode of angina is not a heart attack. Angina pain means that some of the heart muscle in not getting enough
blood temporarily--for example, during exercise, when the heart has to work harder. The pain does NOT mean
that the heart muscle is suffering irreversible, permanent damage. Episodes of angina seldom cause permanent
damage to heart muscle.
In contrast, a heart attack occurs when the blood flow to a part of the heart is suddenly and permanently cut off.
This causes permanent damage to the heart muscle. Typically, the chest pain is more severe, lasts longer, and
does not go away with rest or with medicine that was previously effective. It may be accompanied by indigestion,
nausea, weakness, and sweating. However, the symptoms of a heart attack are varied and may be considerably
When someone has a repeating but stable pattern of angina, an episode of angina does not mean that a heart
attack is about to happen. Angina means that there is underlying coronary heart disease. Patients with angina are
at an increased risk of heart attack compared with those who have no symptoms of cardiovascular disease, but
the episode of angina is not a signal that a heart attack is about to happen. In contrast, when the pattern of angina
changes--if episodes become more frequent, last longer, or occur without exercise--the risk of heart attack in
subsequent days or weeks is much higher.
A person who has angina should learn the pattern of his or her angina--what cause an angina attack, what it feels
like, how long episodes usually last, and whether medication relieves the attack. If the pattern changes sharply or if
the symptoms are those of a heart attack, one should get medical help immediately, perhaps best done by seeking
an evaluation at a nearby hospital emergency room.
Is all chest pain "angina?"
No, not at all. Not all chest pain is from the heart, and not all pain from the heart is angina. For example, if the
pain lasts for less that 30 seconds or if it goes away during a deep breath, after drinking a glass of water, or by
changing position, it almost certainly is NOT angina and should not cause concern. But prolonged pain, unrelieved
by rest and accompanied by other symptoms may signal a heart attack.
How is angina diagnosed?
Usually the doctor can diagnose angina by noting the symptoms and how they arise. However one or more
diagnostic tests may be needed to exclude angina or to establish the severity of the underlying coronary disease.
These include the electrocardiogram (ECG) at rest, the stress test, and x- rays of the coronary arteries (coronary
"arteriogram" or "angiogram").
The ECG records electrical impulses of the heart. These may indicate that the heart muscle is not getting as much
oxygen as it needs ("ischemia"); they may also indicate abnormalities in heart rhythm or some of the other possible
abnormal features of the heart. To record the ECG, a technician positions a number of small contacts on the
patient's arms, legs, and across the chest to connect them to an ECG machine.
For many patients with angina, the ECG at rest is normal. This is not surprising because the symptoms of angina
occur during stress. Therefore, the functioning of the heart may be tested under stress, typically exercise. In the
simplest stress test, the ECG is taken before, during, and after exercise to look for stress related abnormalities.
Blood pressure is also measured during the stress test and symptoms are noted.
A more complex stress test involves picturing the blood flow pattern in the heart muscle during peak exercise and
after rest. A tiny amount of a radioisotope, usually thallium, is injected into a vein at peak exercise and is taken up
by normal heart muscle. A radioactivity detector and computer record the pattern of radioactivity distribution to
various parts of the heart muscle. Regional differences in radioisotope concentration and in the rates at which the
radioisotopes disappear are measures of unequal blood flow due to coronary artery narrowing, or due to failure of
uptake in scarred heart muscle.
The most accurate way to assess the presence and severity of coronary disease is a coronary angiogram, an x-ray
of the coronary artery. A long thin flexible tube (a "catheter") is threaded into an artery in the groin or forearm and
advanced through the arterial system into one of the two major coronary arteries. A fluid that blocks x-rays (a
"contrast medium" or "dye") is injected. X-rays of its distribution show the coronary arteries and their narrowing.
How is angina treated?
The underlying coronary artery disease that causes angina should be attacked by controlling existing "risk factors."
These include high blood pressure, cigarette smoking, high blood cholesterol levels, and excess weight. If the
doctor has prescribed a drug to lower blood pressure, it should be taken as directed. Advice is available on how
to eat to control weight, blood cholesterol levels, and blood pressure. A physician can also help patients to stop
smoking. Taking these steps reduces the likelihood that coronary artery disease will lead to a heart attack.
Most people with angina learn to adjust their lives to minimize episodes of angina, by taking sensible precautions
and using medications if necessary.
Usually the first line of defense involves changing one's living habits to avoid bringing on attacks of angina.
Controlling physical activity, adopting good eating habits, moderating alcohol consumption, and not smoking are
some of the precautions that can help patients live more comfortably and with less angina. For example, if angina
comes on with strenuous exercise, exercise a little less strenuously, but do exercise. If angina occurs after heavy
meals, avoid large meals and rich foods that leave one feeling stuffed. Controlling weight, reducing the amount of
fat in the diet, and avoiding emotional upsets may also help.
Angina is often controlled by drugs. The most commonly prescribed drug for angina is nitroglycerin, which relieves
pain by widening blood vessels. This allows more blood to flow to the heart muscle and also decreases the work
load of the heart. Nitroglycerin is taken when discomfort occurs or is expected. Doctors frequently prescribe
other drugs, to be taken regularly, that reduce the heart's workload. Beta blockers slow the heart rate and lessen
the force of the heart muscle contraction. Calcium channel blockers are also effective in reducing the frequency
and severity of angina attacks.
What if medication fails to control angina?
Doctors may recommend surgery or angioplasty if drugs fail to ease angina or if the risk of heart attack is high.
Coronary artery bypass surgery is an operation in which a blood vessel is grafted onto the blocked artery to
bypass the blocked or diseased section so that blood can get to the heart muscle. An artery from inside the chest
(an "internal mammary" graft) or long vein from the leg (a "saphenous vein" graft) may be used.
Balloon angioplasty involves inserting a catheter with a tiny balloon at the end into a forearm or groin artery. The
balloon is inflated briefly to open the vessel in places where the artery is narrowed. Other catheter techniques are
also being developed for opening narrowed coronary arteries, including laser and mechanical devices applied by
means of catheters.
Can a person with angina exercise?
Yes. It is important to work with the doctor to develop an exercise plan. Exercise may increase the level of
pain-free activity, relieve stress, improve the heart's blood supply, and help control weight. A person with angina
should start an exercise program only with the doctor's advice. Many doctors tell angina patients to gradually build
up their fitness level--for example, start with a 5-minute walk and increase over weeks or months to 30 minutes or
1 hour. The idea is to gradually increase stamina by working at a steady pace, but avoiding sudden bursts of
What is the difference between "stable" and "unstable" angina?
It is important to distinguish between the typical stable pattern of angina and "unstable" angina.
Angina pectoris often recurs in a regular or characteristic pattern. Commonly a person recognizes that he or she is
having angina only after several episodes have occurred, and a pattern has evolved. The level of activity or stress
that provokes the angina is somewhat predictable, and the pattern changes only slowly. This is "stable" angina, the
most common variety.
Instead of appearing gradually, angina may first appear as a very severe episode or as frequently recurring bouts
of angina. Or, an established stable pattern of angina may change sharply; it may by provoked by far less exercise
than in the past, or it may appear at rest. Angina in these forms is referred to as "unstable angina" and needs
prompt medical attention.
The term "unstable angina" is also used when symptoms suggest a heart attack but hospital tests do not support
that diagnosis. For example, a patient may have typical but prolonged chest pain and poor response to rest and
medication, but there is no evidence of heart muscle damage either on the electrocardiogram or in blood enzyme
Are there other types of angina?
There are two other forms of angina pectoris. One, long recognized but quite rare, is called Prinzmetal's or variant
angina. This type is caused by vasospasm, a spasm that narrows the coronary artery and lessens the flow of blood
to the heart. The other is a recently discovered type of angina called microvascular angina. Patients with this
condition experience chest pain but have no apparent coronary artery blockages. Doctors have found that the
pain results from poor function of tiny blood vessels nourishing the heart as well as the arms and legs.
Microvascular angina can be treated with some of the same medications used for angina pectoris.
Facts About Blood Cholesterol (revised 1994), NIH Publication No. 94-2696
Fact About Coronary Heart Disease (reprinted 1993), NIH Publication No. 93-2265
Facts About Heart Failure (reprinted 1995) NIH Publication No. 95-923
Facts About Heart Disease and Women: So You Have Heart Disease, NIH Publication No. 95-2645
High Blood Pressure and What You Can Do About It, No. 55-222A
So You Have High Blood Cholesterol (revised 1993), NIH Publication No. 93-2922
Step by Step: Eating to Lower Your High Blood Cholesterol (revised 1994) NIH Publication No. 94-2920
For Further Information
Call or Write:
National Heart, Lung, and Blood Institute
P.O. Box 30105
Bethesda, MD 20892-0105
Telephone: (301) 251-1222
Information provided by NIH.