The following are a few tests your doctor can perform to see
if you have a heart problem or are at risk for one.
Blood Pressure Test
Measuring blood pressure is one of the easiest ways the risk for heart
disease can be detected. Blood pressure is the amount of force blood
exerts against the walls of the arteries. The higher the blood pressure,
the higher the risk of heart problems. Unfortunately, there are usually
no symptoms of high blood pressure -- many people have high blood
pressure for years without even knowing about it.
That's why it's important to have blood pressure measured regularly.
It should be checked at least every two years--more often if you're
at high risk (see risk factors).
If you've had your blood pressure checked before, you are probably
familiar with the inflatable arm band and gauge known as a sphygmomanometer.
The doctor, nurse, or health care provider wraps the band around your
upper arm, pumping it with air and briefly stopping the flow of blood
in your arm. The gauge records the blood pressure against the band
while the doctor uses a stethoscope to listen to the sound of your
blood pressure as the band deflates.
The provider records two numbers from the gauge. The higher number
is recorded when the provider first hears the pulse. This is your
systolic number that represents the pressure while the heart is contracting.
The provider records the number on the gauge when the heart sounds
disappear. This is your diastolic number that represents the pressure
when the heart is resting between beats. The systolic number is always
read first and the diastolic second, i.e. 122/76 (122 over 76).
A blood pressure reading of less than 120/80 is considered normal
for adults. A reading equal to or greater than 140/90 is defined as
high blood pressure and will require additional observation. |
Blood tests
Your doctor may order a battery of tests to accurately
diagnose the problem. A complete blood cell count can detect such
disorders as anemia (lack of red blood cells) and measures the level
of lipids (cholesterol) in the blood. Testing your body's cholesterol
level is a good way to find out if you are at increased risk for heart
disease. The higher your blood cholesterol level, the more likely
that fats and cholesterol will build up in your artery walls, thereby
narrowing the arteries and slowing the blood flow. Over time, these
build-ups can clog arteries and lead to a heart disease.
Cholesterol tests are widely available, inexpensive and risk-free.
A health care professional will simply take a small sample of blood
and either analyze it at the screening site or send it to a lab. The
test will analyze your blood and look at the total cholesterol level,
and then pare it down to high-density lipoproteins or low-density
lipoproteins. Usually, in order to be as accurate as possible, your
physician may require you to fast overnight in order to control for
fat from foods recently consumed.
When you get your results, first look at the number for your total
cholesterol -- presented in milligrams per deciliter (mg/dl). A total
cholesterol level of less than 200 is desirable. If your cholesterol
is between 200 and 239, you are in the borderline high risk group
for heart disease. (However, depending on other factors, not every
person in this level is at increased risk for narrowed or blocked
arteries -- your provider can interpret your results.) If your cholesterol
level is 240 or more, you are considered to be at high risk for heart
disease.
Sometimes numbers for HDL (high density lipoprotein) and LDL (low
density protein) are also given. HDL is often called "good"
cholesterol because it is believed to carry cholesterol out of the
arteries to the liver, while LDL is referred to as "bad"
cholesterol because it tends to build up in the artery walls. In general,
your HDL cholesterol should be above 35 mg/dl and your LDL cholesterol
should be below 130 mg/dl. If you have other risk factors for heart
disease, your health care provider may recommend ways to lower the
numbers.
Start having your cholesterol tested at around age 20. Your cholesterol
levels may vary from time to time because of changes in diet, medicine
you are taking and physical activity. Ask your health care provider
how often you should have the test repeated, depending on your risk
factors. |
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Stress Test (ECG)
Electrocardiography (ECG or EKG) is a valuable technique for discovering
information about the heart. Basically, it is a recording of the
electrical activity of your heart, often shown on paper or on a
monitor in the form of "waves." Health care providers
can interpret these waves to learn a great deal about the presence
of heart damage as well as about the blood and oxygen supplied to
the heart.
A resting ECG is a useful screening test for coronary artery disease
if you have any symptoms such as chest pain or shortness of breath.
The ECG is also often performed while the patient is exercising
on a treadmill or stationary bike. This is known as a stress test.
The benefit of a stress test is that it is usually easier to detect
circulation problems while the heart is beating at a higher rate.
During the test, several sticky patches known as electrodes are
attached to your body to read your heart's electrical impulses.
The electrodes are painless. In some cases, men with excess hair
on their chests may have to have some hair shaven off since contact
with the skin must be secure. The health care provider then gathers
information from the tracing; each electrode records impulses from
various areas of your heart. Remember, the electrodes will not shock
or hurt you because they are merely recording electrical impulses
from your heart, not sending them to your heart.
The provider makes recordings before, during, and after you exercise.
Each recording only takes about 15 seconds. While you are exercising,
the degree of difficulty is increased in stages, possibly until
you are too tired to continue. Of course, if you experience chest
pain or shortness of breath, the provider will stop the exercise
portion of the test. Although there is no pain or risk from the
actual ECG, the stress test does have a small risk of over-stressing
the heart, but the complications are rare.
The ECG consists of three components:
- P Wave -- represents the depolarization of the atria, the top
portion of the heart
- QRS Complex -- represents the depolarization of the ventricle,
the bottom portion of the heart
- ST Segment (T-wave) -- represents the repolarization of the
ventricle, the rest period until the next contraction.
These readings (a normal and abnormal
reading) are from a "12 lead ECG". A "lead"
is an electrical picture. The lead is generated from wires which
are placed on the limbs and across the chest. Usually ten wires
are used for a 12 lead ECG. Each wire records the same electrical
impulse, but from a different position in relation to the heart.
When reading an ECG, a physician will note the elevations and depressions
of the three segments of the heart beat.
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Echocardiography (Ultrasound)
Echocardiography uses ultrasound to uncover various facts about your
heart's health, from its size to abnormal blood flow problems to the
presence of damaged heart muscle. This noninvasive procedure is safe
and can be done in a cardiologist's office or laboratory as well as
in the hospital.
Before the test, a gel or oil is spread on your chest to improve the
transmission of the ultrasound waves. Then a health care provider
will move a special device called a transducer across your chest.
A transducer is a microphone-shaped, hand-held machine that sends
ultrasound waves into your body and detects the waves bouncing back
from the surfaces of your heart.
A physician will order an echocardiogram to observe how the heart
functions. Echocardiography works like sonar. Sound waves are directed
into the chest, and an audio and visual recording is made of how the
waves rebound from the heart's walls and valves. From this moving
picture, the physician can determine the shape, texture and function
of the valves and heart chambers. In a color Doppler study, like the
one below, the physician can also determine the direction and velocity
of blood flow, as represented by the different colors. An echocardiogram
is painless, and posses no risk to the patient.
The first frame shows a color flow Doppler study from a normal, healthy
heart. The colors represent appropriate direction and intensity of
blood flow. The second frame shows a heart which is abnormal. The
color flow Doppler shows a connection between the left and right atria,
which are the upper two chambers of the heart.
*click on image to enlarge
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Normal, Healthy Ultrasound
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Abnormal Ultrasound
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Taking anywhere from 15 minutes to over an hour, this procedure is
virtually risk-free and usually painless, although occasionally you
will feel the pressure of the transducer on your chest. Like the ECG,
the echocardiography test can also be performed as a stress test.
To do this, the provider takes an echocardiogram before and after
a brief period of exercise on a treadmill. |
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