Some 7 million Americans suffer from
coronary heart disease (CHD), the most common form of heart disease. This
type of heart disease is caused by a narrowing of the coronary arteries that
feed the heart.
CHD is the number one killer of both men and women in
the U.S. Each year, more than 500,000 Americans die of heart attacks caused
Many of these deaths could be prevented because CHD is related
to certain aspects of lifestyle. Risk factors for CHD include high blood
pressure, high blood cholesterol, smoking, obesity, and physical
inactivity-- all of which can be controlled.
treatments for heart disease have come a long way, controlling risk factors
remains the key to preventing illness and death from CHD.
Who Is at
Risk for CHD?
Risk factors are conditions that increase your risk of
developing heart disease. Some can be changed and some cannot. Although
these factors each increase the risk of CHD, they do not describe all the
causes of the disease; even with none of these risk factors, you might still
Controllable Uncontrollable High blood
pressure Gender High blood cholesterol Heredity (family history of
CHD) Smoking Age Obesity Physical
Activity Diabetes Stress* * Although stress may be a risk factor for
CHD, scientists still do not know exactly how stress might be involved in
What Is CHD?
Like any muscle, the heart needs a
constant supply of oxygen and nutrients that are carried to it by the blood
in the coronary arteries. When the coronary arteries become narrowed or
clogged and cannot supply enough blood to the heart, the result is CHD. If
not enough oxygen-carrying blood reaches the heart, the heart may respond
with pain called angina. The pain is usually felt in the chest or
sometimes in the left arm and shoulder. (However, the same inadequate
blood supply may cause no symptoms, a condition called silent
When the blood supply is cut off completely, the result is a
heart attack. The part of the heart that does not receive oxygen begins to
die, and some of the heart muscle may be permanently damaged.
CHD is caused by a thickening of the inside walls of the
coronary arteries. This thickening, called atherosclerosis, narrows the
space through which blood can flow, decreasing and sometimes completely
cutting off the supply of oxygen and nutrients to the
Atherosclerosis usually occurs when a person has high levels
of cholesterol, a fat-like substance, in the blood. Cholesterol and
fat, circulating in the blood, build up on the walls of the arteries. The
buildup narrows the arteries and can slow or block the flow of blood. When
the level of cholesterol in the blood is high, there is a greater chance
that it will be deposited onto the artery walls. This process begins in most
people during childhood and the teenage years, and worsens as they get
In addition to high blood cholesterol, high blood pressure and
smoking also contribute to CHD. On the average, each of these doubles your
chance of developing heart disease. Therefore, a person who has all three
risk factors is eight times more likely to develop heart disease than
someone who has none. Obesity and physical inactivity are other factors that
can lead to CHD.
Overweight increases the likelihood of developing high
blood cholesterol and high blood pressure, and physical
inactivity increases the risk of heart attack. Regular exercise, good
nutrition, and smoking cessation are key to controlling the risk factors
What Are the Symptoms of CHD?
Chest pain (angina) or
shortness of breath may be the earliest signs of CHD. A person may feel
heaviness, tightness, pain, burning, pressure, or squeezing, usually behind
the breastbone but sometimes also in the arms, neck, or jaws. These signs
usually bring the patient to a doctor for the first time. Nevertheless, some
people have heart attacks without ever having any of these
It is important to know that there is a wide range of
severity for CHD. Some people have no symptoms at all, some have mild
intermittent chest pain, and some have mild intermittent chest pain, and some
have more pronounced and steady pain.Still others have CHD that is severe
enough to make normal everyday activities difficult.
varies so much from one person to another, the way a doctor diagnoses and
treats CHD will also vary a lot.
The following descriptions are general
guidelines to some tests and treatments that may or may not be
used, depending on the individual case.
Are There Tests for
There is no one simple test--some or all of the following
procedures may be needed. These diagnostic procedures are used to establish
CHD, to determine its extent and severity, and to rule out other possible
causes of the symptoms.
After taking a careful medical history and doing
a physical examination, the doctor may use some tests to see how advanced
the CHD is. The only certain way to diagnose and assess the extent of CHD
is coronary angiography (see below); other tests can indicate a problem
but do not show exactly where it is.
An examination for CHD may include
the following tests:
An electrocardiogram (ECG or EKG) is a graphic
record of the electrical activity of the heart as it contracts and
Abnormal heartbeats and some areas of damage, inadequate blood
flow, and heart enlargement can be detected on the records.
test (also called a treadmill test or exercise ECG) is used to record the
heartbeat during exercise. This is done because some heart problems only
show up when the heart is working hard. In the test, an ECG is done
before, during, and after exercising on a treadmill; breathing rate and
blood pressure may be measured as well. Exercise tests are useful but are
not completely reliable; false positives (showing a problem where none
exists) and false negatives (showing no problem when something is wrong) are
Nuclear scanning is sometimes used to show
damaged areas of the heart and expose problems with the heart's pumping
action. A small amount of radioactive material is injected into a
vein, usually in the arm. A scanning camera records the nuclear material
that is taken up by heart muscle (healthy areas) or not taken up (damaged
Coronary angiography (or arteriography) is a test used to
explore the coronary arteries. A fine tube (catheter) is put into an
artery of an arm or leg and passed through the tube into the arteries of
the heart. The heart and blood vessels are then filmed while the heart
pumps. The picture that is seen, called an angiogram or arteriogram, will
show problems such as a blockage caused by atherosclerosis.
How Is CHD
CHD is treated in a number of ways, depending on the
seriousness of the disease. For many people, CHD is managed with lifestyle
changes and medications. Others with severe CHD may need surgery. In any
case, once CHD develops, it requires lifelong management.
What Kind of
Lifestyle Changes Can Help a Person with CHD?
Although great advances
have been made in treating CHD, changing one's habits remains the single most
effective way to stop the disease from progressing.
If you know that
you have CHD, changing your diet to one low in fat, especially
saturated fat, and cholesterol will help reduce high blood cholesterol, a
primary cause of atherosclerosis. In fact, it is even more important to keep
your cholesterol low after a heart attack to help lower your risk of
having another one. Eating less fat should also help you lose weight. If
you are overweight, losing weight can help lower blood cholesterol and is
the most effective lifestyle way to reduce high blood pressure, another
risk factor for atherosclerosis and heart disease.
People with CHD
can also benefit from exercise. Recent research has shown that even moderate
amounts of physical activity are associated with lower death rates from
CHD. However, people with severe CHD may have to restrict their
exercise somewhat. If you have CHD, check with your doctor to find out
what kinds of exercise are best for you.
Smoking is one of the three
major risk factors for CHD. Quitting smoking dramatically lowers the risk of
a heart attack and also reduces the risk of a second heart attack in
people who have already had one.
What Medications Are Used to Treat
Medications are prescribed according to the nature of the
patient's CHD and other problems. The symptoms of angina can generally be
controlled by "beta-blocker" drugs that decrease the workload on the
heart, by nitroglycerine and other "nitrates" and by "calcium-channel
blockers" that relax the arteries, and by other classes of drugs. The
tendency to form clots is reduced by aspirin or by other platelet inhibitory
and anticoagulant drugs.
Beta-blockers are given to decrease
the recurrence of heart attack. For those with elevated blood cholesterol
that is unresponsive to dietary and weight loss measures,
cholesterol-lowering drugs may be prescribed, such as
lovastatin, colestipol,cholestyramine, gemfibrozil, and niacin. Impaired
pumping function of the heart may be treated with digitalis drugs or ACE
inhibitors. If these is high blood pressure or fluid retention, these
conditions are also treated.
Ask your doctor which medication you are
taking, what it does, and whether there are any side effects. Knowing
more about this will help you stick to the schedule that has been prescribed
What Types of Surgery Are Used to Treat CHD?
patients can control CHD with lifestyle changes and medication. Surgery may
be recommended for patients who continue to have frequent or disabling
angina despite the use of medications, or people who are found to
have severe blockages in their coronary arteries.
or balloon angioplasty begins with a procedure similar to that
described under angiography. However, the catheter positioned in the
narrowed coronary artery has a tiny balloon at its tip. The balloon is
inflated and deflated to stretch or break open the narrowing and improve
the passage for blood flow. The balloon-tipped catheter is then
Strictly speaking, angioplasty is not surgery. It is done
while the patient is awake and may last 1 to 2 hours. If angioplasty does
not widen the artery or if complications occur, bypass surgery may be
In a coronary artery bypass operation, a blood vessel, usually
taken from the leg or chest, is grafted onto the blocked artery, bypassing
the blocked area. If more than one artery is blocked, a bypass can be
done on each. The blood can then go around the obstruction to supply the
heart with enough blood to relieve chest pain.
Bypass surgery relieves
symptoms of heart disease but does not cure it. Usually you will need to
make a number of changes in your lifestyle after the operation. If your
normal lifestyle includes smoking, a high-fat diet, or no
exercise, changes are advised.
Several experimental catheter-surgical
procedures for unblocking coronary arteries are under study; their safety
and effectiveness have not yet been established. They
include: Atherectomy, a procedure in which surgeons shave off thin strips
of the plaque blocking the artery and remove these strips.
angioplasty; instead of using a balloon to open up the blocked
artery, doctors insert a catheter with a laser tip that burns or breaks
down the plaque.
Insertion of a stent, a metal coil that can be
permanently implanted in a narrowed part of an artery to keep it propped
For further information contact:
National Heart Lung, and
Blood Institute (NHLBI) Information Center P.O. Box 30105 Bethesda MD
20824-0105 Acknowledgement: U.S. Department of Health and Human
Services Public Health Service National Institutes of Health The
National Heart, Lung, and Blood Institute NIH Publication No. 93-2265