What
is angina?
What
brings on angina?
Does
angina mean a heart attack is about to happen?
Is
all chest pain "angina?"
How
is angina diagnosed?
How
is angina treated?
What
if medication fails to control angina?
Can
a person with angina exercise?
What
is the difference between "stable" and "unstable"
angina?
Are
there other types of 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 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 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 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.
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 tests.
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.
Reference:
from the National Heart, Lung, and Blood Institute
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