|
Medical Tests to Detect CAD
- Blood cholesterol: Blood tests to monitor cholesterol levels are typically
performed once every five years for adults between the ages of 20 and 35 if the levels are
normal. After age 35, cholesterol tests are typically monitored every two years or every
year depending on age, family history, test results, etc.
| Total
cholesterol (mg/dL) |
LDL
cholesterol (mg/dL) |
HDL
cholesterol (mg/dL) |
Ideal: Less than 200
Borderline high risk: 200-239
High risk: 240 and over |
Ideal: less than 130
Borderline high risk: 130-159
High risk: 160 or higher |
Ideal: 60 or higher
High risk: lower than 40 |
- Blood pressure: Blood pressure is usually taken during each office visit or other
regular interval.
| (mm
Hg) |
Ideal |
Normal |
High
Normal |
Hypertension |
| Systolic (top
number) |
Less than 120 |
Less than 130 |
130-139 |
140 or higher |
Diastolic
(bottom number) |
Less than 80 |
Less than 85 |
85-89 |
90 or higher |
*source: American Heart Association
- Chest x-ray: A chest x-ray images the heart and
surrounding thoracic anatomy, shows heart size and shape, and reveals whether the heart is
misshaped or enlarged due to disease. Abnormal calcification (hardened blockage due to
cholesterol build up) in the main blood vessels and fluid in the lungs (possible
indication of congestive heart failure) can also be seen. Chest x-rays can also be used to
image pacemakers and artificial heart valves to check for correct positioning.
- Electrocardiogram (ECG or EKG): An electrocardiogram is a graphical record of
the electrical activity of the heart. A normal ECG, in most cases, rules out the presence
of other cardiac diseases. An abnormal ECG indicates the presence of a cardiac disease and
further investigations are performed. An ECG can be beneficial in detecting the disease
and sometimes even the extent of the disease.
- Stress test: A stress test involves taking an EKG before, during and after a
treadmill workout to detect possible cardiac disease and/or damage, including the extent
of CAD. However, false positive results are possible with stress tests. A stress test is
typically performed on adults 40 years of age or older who are at high risk for CAD.
Fast/multi-slice CT scan: Fast/multi-slice spiral CT
scan with ECG gating is a new non-invasive method of imaging the heart and coronary
arteries. In some cases, ECG gated fast/multi-slice CT eliminates the need for
conventional cardiac angiography which requires invasive catheterization. Fast/multi-slice
CT is particularly useful in that it can show calcium deposits in the coronaries that form
with plaque-build up and may eventually lead to myocardial
infarction (heart attack). Early imaging of stenoses (narrowing of arteries) and
calcium deposits in the coronary arteries can allow aggressive preventive measures or
treatment to be implemented, thus lowering the risk of myocardial infarction.
 |
| 3D reconstructed heart showing
coronary arteries in red, acquired with EBCT |
EBCT has established itself as a very
fast, non-invasive means to image the heart and coronary arteries. EBCT eliminates the
need for catheterization and contrast injection which is required in conventional cardiac
angiography. EBCT is particularly useful in that it can show calcium deposits in the
coronaries. The calcium deposits form along with the plaque-build up and eventually lead
to heart failure. Early imaging of calcium deposits in the coronary arteries can allow
aggressive preventive measures to be implemented, thus lowering the risk of heart attack.
EBCT is a special type
of computed tomography (CT) that uses a sweeping electron beam to create the rotating
x-ray effect needed to make a computed tomography image. This makes EBCT different from
conventional CT which has an x-ray tube mounted on a rotating frame. By using a sweeping
electron beam, EBCT images can be acquired in as fast as 50 or 100 milliseconds, or some
10 times faster than the fastest slip-ring CT systems that can acquire an image in about
500 milliseconds. In order to image the beating heart and eliminate all image degradation
caused by heart motion, image acquisition time must be in the 100 millisecond or faster
range. In other words, a conventional slip-ring CT scanner can acquire one to two
image per second while an EBCT system can acquire at a much faster rate of 10 to 20 images
per second.
- Ambulatory monitoring: If no abnormality, disease or damage is detected and the
patient still feels uneasy when performing stressful activities (such as climbing stairs)
but feels okay under normal activity, then an ambulatory monitor may be used. An
ambulatory monitor is a portable EKG system (often worn around the waist) that
continuously monitors the heart’s electrical activity.
Updated: February 29, 2008
< Prev | 1 | 2
Return to Coronary Artery Disease Overview |
