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
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 milder.
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
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
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 effort.
What is the difference between "stable"
and "unstable" angina?
It is important to distinguish between the typical stable pattern
of angina and "unstable" angina.
What is stable angina?
People with stable angina (or chronic stable angina) have episodes
of chest discomfort that are usually predictable. They occur on
exertion (such as running to catch a bus) or under mental or emotional
stress. Normally the chest discomfort is relieved with rest and/or
People with episodes of chest discomfort should see their physician
for an evaluation. The doctor will evaluate the person's medical
history and risk factors, conduct a physical exam, order a chest
X-ray and take an electrocardiogram (ECG). Some people will also
need an exercise ECG (stress test), an echocardiogram (ek"o-KAR'de-o-gram)
or other tests to complete the diagnosis.
What is unstable angina?
In people with unstable angina, the chest pain is unexpected
and usually occurs while at rest. The discomfort may be more severe
and prolonged than typical angina or be the first time a person
has angina. The most common cause is reduced blood flow to the
heart muscle due to narrowing of the coronary arteries by atherosclerosis
(ath"er-o-skleh-RO'sis). An artery may be abnormally constricted
or partially blocked by a blood clot. Inflammation, infection
and secondary causes can also lead to unstable angina. In a form
of unstable angina called variant or Prinzmetal's angina, the
cause is coronary artery spasm.
Unstable angina is an acute coronary syndrome and should be treated
as an emergency. People with new, worsening or persistent chest
discomfort should be evaluated in a hospital emergency department
or "chest pain unit" and monitored carefully. They're
at increased risk for
acute myocardial infarction (mi"o-KAR'de-al in-FARK'shun)
severe cardiac arrhythmias (ah-RITH'me-ahz). These may include ventricular
tachycardia (ven-TRIK'u-ler tak"eh-KAR'de-ah) and fibrillation
cardiac arrest leading to sudden death.
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.
What is variant angina pectoris (Prinzmetal's
Variant angina pectoris is also called Prinzmetal's angina.
Unlike typical angina, it nearly always occurs when a person is
at rest. It doesn't follow physical exertion or emotional stress,
either. Attacks can be very painful and usually occur between
midnight and 8 a.m.
Variant angina is due to coronary artery spasm. About two-thirds
of people with it have severe coronary atherosclerosis in at least
one major vessel. The spasm usually occurs very close to the blockage.
Angina can also occur in people with valvular heart disease, hypertrophic
cardiomyopathy (hi"per-TRO'fik kar"de-o-mi-OP'ah-the)
or uncontrolled high blood pressure -- though these cases are rare.
How is variant angina or Prinzmetal's angina
Calcium antagonists are extremely effective in preventing coronary
spasms of variant or Prinzmetal's angina. These drugs, along with
nitrates, are the mainstays of treatment. Prinzmetal's angina
tends to be cyclic, appearing for a time, then going away. Because
of this, after six to 12 months of treatment, the calcium antagonists
may be gradually reduced. In some cases PTCA is used when a blockage
is thought to cause the spasm.
Another 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.