The prevalence of
coronary atherosclerosis increases with age, and is about 50% in the 50 year old
An Electron Beam CT
scan can both detect and measure the extent of coronary calcification, and can
identify those people at greatest risk of a heart attack. However, it should be noted that there are many people
between 50 and 70 who have no
coronary calcium whatsoever, which means that they have a very low risk
of having obstructive Coronary Artery Disease or heart attacks.
detector or coronary calcium scan will be able to tell you whether you have
heart disease. It can detect
heart disease at its very early stage, even before any cardiac symptoms are
noticeable and even before your stress test indicate any abnormality.
This is especially beneficial for those who have no symptoms but who may
have one or more of the following cardiac risk factors :
(males above 40, females above 45)
family history of heart
high blood pressure
If you wish to find
out how blocked your arteries are, a
non-invasive Electron Beam Angiogram(EBA) will be able to do so to
an accuracy of greater than 90%. This
involves the use of non-ionic (to minimize risk of allergies) contrast or dye
injected through a vein in the arm. The
computer then reconstructs the images to enable you and your doctor to visualize
the coronary arteries in 3D. The
EBA will give valuable information to the patient and his doctor prior to a
traditional invasive angiogram and is useful for certain indications depending
on the condition of the individual.
A normal EBA means
that the patient does not have to undergo an invasive
angiogram. However an invasive
angiogram may still be needed when severe obstructive coronary artery disease is
diagnosed and when it is necessary to undergo angioplasty or bypass surgery.
The indications for EBA are
patients with mild to moderate
patients with severe coronary calcification
of coronary angioplasty, coronary bypass
of coronary patency post MI or stent
of coronary artery congenital or acquired
risk" patients with abnormal stress tests
Most other tests in
cardiology, such as exercise stress ECG or stress thallium or stress
echocardiograms detect abnormality in heart function and therefore only reliably
detect heart disease when the disease is so advanced that it hinders your heart
from working properly.
EBCT scan looks
directly at the coronary arteries and measures the plaque burden and it can
detect heart disease at a very early stage, usually many years before a person
Each test in cardiology serves a specific
purpose. EBCT coronary artery scanning is the best available screening test for
detecting early heart disease, and is usually performed before any of the other
cardiac tests, including a stress test. The
stress test still has a role to play, and it is useful to determine whether a
patient has ischaemia due to severe obstructive coronary artery disease which
requires urgent angioplasty or bypass surgery.
if I have already passed an exercise stress test or stress thallium test ?
This means that your
heart function is normal, even when you are pushed to peak exertion.
But it does not mean that you have no coronary atherosclerosis. Your
coronary arteries may not be clean, i.e. you may have plaque build up but it is
not causing any obstruction to blood flow yet. There
are patients who die suddenly of a
heart attack despite having a negative stress test.
This fact, first published in The New England Journal of Medicine in
1989, seems paradoxical. Most
people still believe that heart attacks happen when coronary arteries become
severely blocked. In reality, most
heart attacks occur due to plaque rupture or ulceration, and can happen even
when the blood vessel is not even 50% blocked.