Coronary artery disease
Screening and diagnosis
How can you know whether you have this silent, potential killer? Your
doctor can help answer that question based on test results and your
level of risk.
If you have risk factors for coronary artery disease, your doctor may
want to test you for coronary artery disease, even if you don't have
signs or symptoms of narrowed arteries. You may be referred to a
cardiologist, a doctor who specializes in diagnosing and treating
cardiovascular problems. The term cardiovascular refers to your
body's circulatory system — your heart, arteries and veins.
In addition to a physical examination, taking your medical history and
routine blood tests, your doctor may recommend these tests to diagnose
coronary artery disease:
In this test, which is sometimes called an EKG, patches with wires
(electrodes) are attached to your skin to measure electrical
impulses given off by your heart. This test can show evidence of a
previous heart attack or one that's in progress. It can also yield
other useful information, such as the status of your heart's
electrical system. ECG readings taken continuously over a period of
24 hours or longer may help detect silent ischemia. This technique
is called ambulatory electrocardiography monitoring, or Holter
monitoring. Electrodes attached to your chest are connected to a
portable monitor — about the size of a paperback book or smaller —
that attaches to your belt or is carried by a shoulder strap. You
wear the monitor for 24 hours as you go about your normal
activities. Recorded abnormalities may show evidence of inadequate
blood supply to your heart.
This test uses sound waves to produce an image of your heart. An
echocardiogram can help identify whether an area of your heart has
been damaged from lack of blood supply by assessing how well that
area moves during each heartbeat. When combined with a stress test,
an echocardiogram can also help identify areas of diminished blood
flow to your heart.
Stress tests help measure whether your heart is getting adequate
blood supply. They may be used to evaluate symptoms such as chest
pain or shortness of breath during exertion. Or if you have
significant risk factors for coronary artery disease — even if you
have no symptoms — a stress test can be used as a screening tool.
There are several kinds of stress tests. During an exercise stress
test, you walk on a treadmill or pedal a stationary bike while an ECG records your heart's response to an increasing workload. For
people who can't exercise, a medication may be used to "stress" the
heart and mimic the effects of exercise instead. Doctors also
sometimes use imaging tests — an echocardiogram or a nuclear scan —
to provide additional information by generating pictures of your
heart during and after exercise or pharmacologic stress.
angiography (or arteriography).
This has long been considered the definitive test for coronary
artery disease. It can show specific sites of narrowing in coronary
arteries. A small tube (catheter) is inserted into an artery in your
arm or groin and threaded to your heart. A dye is injected into the
catheter. As the dye flows through your coronary arteries, your
doctor can see narrow areas and blockages with the help of X-rays.
magnetic resonance angiography.
This technique uses magnetic waves to produce a three-dimensional
image of your coronary arteries to check for narrowings or
blockages. This technique is still being developed, but it has the
advantage of producing images of your coronary arteries with a
This test also helps identify blood flow problems to your heart.
Trace amounts of radioactive material, such as thallium or a
compound known as Cardiolite, are injected into your bloodstream.
Special cameras can detect areas in your heart that receive less
computerized tomography (EBCT).
This test, also called an ultrafast CT scan, can detect calcium
within plaques that narrow coronary arteries. Most, but not all,
plaques contain some calcium. If a substantial amount of calcium is
discovered, coronary artery disease is likely.
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