ATHEROSCLEROSIS DIAGNOSIS |
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Physicians may be able to make a
diagnosis of atherosclerosis during a physical exam by means of a
stethoscope and gentle probing of the arteries with the hand (palpation).
More definite tests are electrocardiography, echocardiography or
ultrasonography of the arteries (for example, the carotids),
radionuclide scans, and angiography.
An electrocardiogram shows the heart's activity. Electrodes covered
with conducting jelly are placed on the patient's body. They send
impulses of the heart to a recorder. The test takes about 10 minutes
and is performed in a physician's office. Exercise
electrocardiography (stress test) is conducted while the patient
exercises on a treadmill or a stationary bike. It is performed in a
physician's office or an exercise laboratory and takes 15-30
minutes.
Echocardiography, cardiac ultrasound, uses sound waves to create an
image of the heart's chambers and valves. A technician applies gel
to a hand-held transducer, presses it against the patient's chest,
and images are displayed on a monitor. This technique cannot
evaluate the coronary arteries directly. They are too small and are
in motion with the heart. Severe coronary artery disease, however,
may cause abnormal heart motion that is detected by
echocardiography. Performed in a cardiology outpatient diagnostic
laboratory, the test takes 30-60 minutes. Ultrasonography is also
used to assess arteries of the neck and thighs.
Radionuclide angiography and thallium (or sestamibi) scanning enable
physicians to see the blood flow through the coronary arteries and
the heart chambers. Radioactive material is injected into the
bloodstream. A device that uses gamma rays to produce an image of
the radioactive material (gamma camera) records pictures of the
heart. Radionuclide angiography is usually performed in a hospital's
nuclear medicine department and takes 30-60 minutes. Thallium
scanning is usually done after an exercise stress test or after
injection of a vasodilator, a drug to enlarge the blood vessels,
like dipyridamole (Persantine). Thallium is injected, and the scan
is done then and again four hours (and possibly 24 hours) later.
Thallium scanning is usually performed in a hospital's nuclear
medicine department. Each scan takes 30-60 minutes.
Coronary angiography is the most accurate diagnostic method and the
only one that requires entering the body (invasive procedure). A
cardiologist inserts a catheter equipped with a viewing device into
a blood vessel in the leg or arm and guides it into the heart. The
patient has been given a contrast dye that makes the heart visible
to x rays. Motion pictures are taken of the contrast dye flowing
though the arteries. Plaques and blockages, if present, are well
defined. The patient is awake but has been given a sedative.
Coronary angiography is performed in a cardiac catheterization
laboratory and takes from 30 minutes to two hours. |
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| ATHEROSCLEROSIS RELATED ITEMS |
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