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Facts About Coronary
Heart Disease
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 blood to 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 by CHD.
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. Although
medical 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 coronary heart disease; even with none of these risk
factors, you might still develop CHD.
Controllable
High blood pressure
High blood cholesterol
Smoking
Obesity
Physical inactivity
Diabetes
Stress*
Uncontrollable
Gender
Heredity (family history of CHD)
Age
· Although stress may be a risk factor for CHD, scientists still do not know exactly how
stress might be involved in heart disease.
· Recently there is information that certain infections and blood levels of substances
such as homocysteine maybe risk factors for CHD.
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 angina.) Angina is often felt as a pressure like sensation and not a sharp pain.
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.
What causes CHD?
CHD is caused by a thickening of the inside walls of the coronary arteries. This
thickening, called atherosclerosis (hardening of the arteries), narrows the space through
which blood can flow, decreasing and sometimes completely cutting off the supply of oxygen
and nutrients to the heart.
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 older.
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 for CHD.
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 symptoms.
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 more pronounced
and steady pain. Still others have CHD that is severe enough to make normal everyday
activities difficult.
Because CHD 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 CHD?
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 rests. Abnormal heartbeats and some areas of
damage, inadequate blood flow, and heart enlargement can be detected on the records.
- A stress 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 fairly common.
- Echocardiogram and Stress Echo are often used together
with the treadmill test. The echo shows the heart muscle and valves and may help identify
areas of the heart with poor blood supply.
- 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
areas).
- Coronary angiography (or arteriography, or heart catheterization or
heart cath) 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 treated?
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 coronary heart
disease?
Medications are prescribed according to the nature of the patient's CHD and other
problems. The symptoms of angina can sometimes 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.
Impaired pumping function of the heart may be treated with digitalis drugs or ACE
inhibitors. If there 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 for you.
What types of surgery are used to treat CHD?
Many 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.
Coronary angioplasty 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 removed.
Strictly speaking, angioplasty is not surgery. It is done while the patient is awake and
may last 1 to 3 hours. If angioplasty does not widen the artery or if complications occur,
bypass surgery may be needed.
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.
If needed, newer techniques may serve as an adjunct to balloon angioplasty:.
- Atherectomy, a procedure in which surgeons shave off thin strips of the plaque blocking
the artery and remove these strips.
- Insertion of a stent, a metal coil that can be permanently implanted in a narrowed part
of an artery to keep it propped open.
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