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Coronary Artery Disease
Diagnosis
Determining whether chest pain is due to arteriosclerosis can, often be assessed by
reviewing the individual's personal and family medical histories, and descriptions of the
pain including the type and location of the pain, what actions cause the pain, and what
actions make it better. Be prepared to provide this information to your physician.
Physical examinations and laboratory tests may not reveal anything abnormal. This includes
an electrocardiogram (also called ECG or EKG), especially if done when there is no pain.
A sample of your blood may be taken for analysis to determine your cholesterol level.
Other blood tests that may be recommended include measurement of blood sugar level and of
thyroid hormone.
The most specific non-invasive test is the exercise electrocardiogram ("stress
test"). This is an electrocardiographic examination that is done while a person is
exercising. A particular change in the electrocardiogram may be indicative of coronary
artery disease.
By injecting a chemical (Thallium or Technetium) into the blood stream, it's possible to
"observe" using a special scanning device the amount of blood flowing in the
arteries. Your physician may recommended this test in conjunction with the exercise
electrocardiogram.
It raises accuracy of the test slightly. Because of the possible allergic reactions and
the extra expense, many physicians only recommend this in people with particular heart
problems.
This stress test, however, like all medical tests is not 100 percent accurate. Twenty
percent to 30 percent of people with disease will have a normal exam. And 10 percent to 20
percent (higher in women) may have an abnormal exam, but not have the disease.
This later figure has created controversy in the medical community about when the exam
should be done, especially whether it should be conducted on people with a low probability
of having the disease.
Abnormal tests may cause a great deal of anxiety and may lead to the recommendation of
invasive tests (tests that can be very risky). For someone without disease, the anxiety
and increased risk may be detrimental.
Whenever a medical test is abnormal, ask about the probability that the test was in error
(false positive). Also discuss the risks and benefits of possible next steps including
repeating the test.
The most direct way to "see" if the coronary arteries are clogged is through
angiography. This entails the injection of a chemical directly into the coronary arteries
(through a procedure called cardiac catheterization) that acts like a dye on an X-ray
picture. This test will not only indicate whether the disease is present but also in which
arteries it is located and the severity of the narrowing.
This is very useful information to have available in making the decision as to whether or
not to treat the problem with surgery. ,The test itself, however, can cause heart attacks
and subsequent death.
Understanding the risks and benefits of this test are particularly important. In making
the decision to have this test, ask your physician to fully explain how (if at all) the
test results would change treatment recommendations. Also ask him or her to explain the
benefits, risks and costs of the test.
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