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Frequently asked questions about EBCT

  1. What is a heart scan or EBCT scan?

  2. How good is this technology?

  3. What is atherosclerosis and coronary artery disease?

  4. Does everyone suffer from atherosclerosis as they age?

  5. Can a calcium scan tell how blocked my arteries are?

  6. Can this scanner detect heart disease earlier than any other test?

  7. Is this test better than a stress test?

  8. What if I have already passed an exercise stress test or stress thallium test ?

  9. What if I have already had a heart attack,  angioplasty or bypass surgery ?

  10. Who should take this test ?

  11. Is it safe to have a EBCT scan ?

  12. What happens if the test shows that I have coronary calcium ?

  13. Do I need a referral from my doctor to get a heart scan ?  

Myths and Misconceptions about Heart Disease

How to Prevent Heart Attacks

The Heart Facts of Life

What is Heartscan or EBCT?

It is an Electron Beam Tomography scan of the coronary arteries (the vessels which carry blood and oxygen to the heart muscle). 

The scanner detects and measures calcium in the coronary arteries, which is the marker for atherosclerosis (the accumulation of cholesterol plaque in the arteries).  The test is non-invasive with no pain, using no injections, chemicals or incisions.  You just lie on a table, hold your breath for a few seconds and let the scanner take pictures of your heart.  The complete process only takes a few minutes.  

The non-invasive EBCT scan measures coronary disease in a way which many doctors now believe is more important than the percentage of blockage (referred to as stenosis or occlusion).  The scan measures the amount of calcium plaque within your coronary arteries.  This measurement indicates the level of atherosclerosis in a person, i.e., the more calcium you have, the more plaque you have and therefore  the greater the chance that you will suffer a heart attack or need surgery in the future unless you take early steps to prevent this.

Many authoritative studies have shown that an EBCT scan is highly sensitive for detecting Coronary Artery Disease. A negative test is also a very powerful indicator that the patient does not have heart disease.

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How good is this technology?

EBCT was cited as one of the top 10 research advances in heart disease and stroke for 1999 by American Heart Association.  The Food and Drug Administration of USA has given 510(K) market clearance for use of this machine to perform non-invasive Electron Beam Angiogram in November 1999, and EBCT is the only scanner in the world approved for this procedure.

This technology has been validated by more than 15 years of rigorous testing at top universities and medical centers around the world and there are more than 1000 publication of scientific research papers in major international medical journals.

Scientific publications include two important papers from Germany in Radiology February 2000; one demonstrating the accuracy of EBCT for the study of coronary stents, the other showing the advantage of EBCT for detection of pulmonary embolism. Another study from Beijing in the Journal of Invasive Cardiology February 2000 showed the ability of EBCT to evaluate coronary stents with 100% neg. predictive accuracy.  The American Heart Association published a study in Circulation February 2000 showing EBCT to be more sensitive than nuclear medicine or exercise treadmill testing in sub-clinical individuals.

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What is atherosclerosis and coronary artery disease?

Atherosclerosis is the name for the cholesterol plaque buildup inside your coronary arteries.  The presence of atherosclerosis in your coronary arteries means the presence of Coronary Artery Disease.  The greater the amount of plaque build up, the higher would be the risk of a heart attack because most heart attacks are due to plaque rupture or ulceration. When atherosclerosis advances to a stage where the blockage prevents normal blood flow to the heart muscle, it is called obstructive Coronary Artery Disease.

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Does everyone suffer from atherosclerosis as they age?

The prevalence of coronary atherosclerosis increases with age, and is about 50% in the 50 year old population. 

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.

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Can a calcium scan tell me how blocked my arteries are?

A plaque 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 : 

  1. age (males above 40, females above 45)

  2. smoker 

  3. high cholesterol

  4. inactive lifestyle 

  5. family history of heart disease

  6. high blood pressure 

  7. overweight

  8. diabetes

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 as follows:-

  1.  “Symptomatic” patients with mild  to moderate coronary calcification

  2.  “Sub-clinical” patients with severe coronary calcification

  3. Follow-up of coronary angioplasty, coronary bypass

  4. Follow-up of coronary patency post MI or stent

  5. Assessment of coronary artery congenital or acquired anomalies  

  6. "Low risk" patients with abnormal stress tests

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Can this scanner detect heart disease earlier than any other test?

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. 

An 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 becomes symptomatic.

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Is this test better than a stress test?

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.

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What 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.

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What if I have already had a heart attack,  angioplasty or bypass surgery ?

   

For individuals who have had a heart attack,  bypass operation or angioplasty, an EBA can be done to check the conditions of the patient’s heart arteries, the patency of post-bypass grafts or post PTCA vessels. The calcium score is also useful for it can provide a benchmark against which your doctor can measure any future progression of the heart disease.  It is also important that anyone who has had a heart attack, coronary angioplasty or bypass surgery should inform his/her siblings and/or grown-up children about the availability of this test because heart disease is often a hereditary disease.

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Who should take this test ?

Men over the age of 40 and women over the age of 45 should actively consider taking an EBCT scan.  The more risk factors for heart disease you have, e.g. high cholesterol, high blood pressure, smoking, diabetes, obesity, sedentary lifestyle, high stress lifestyle, family history of heart disease, etc., the more important it is that you ask your doctor to recommend you for a scan.  If you are younger than 40, then upon your doctor’s recommendations, you may also take the EBCT scan if you have multiple risk factors.

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Is it safe to have a EBCT scan ?

 A patient is only subjected to a small amount of radiation, approximately equivalent to the radiation received during one abdominal x-ray.  As such, the scan is safe for everyone, although pregnant women are advised against doing so to avoid any radiation.

The EBA involves injection of a non-ionic dye and carries a small risk of allergic reactions, e.g  rashes.

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What happens if the test shows that I have coronary calcium ?

 The results show, on an artery-by-artery basis, the amount of any calcium deposited.  The total amount of calcium (the calcium score) is then compared to the scores of other individuals of your age.  If you do have calcium deposits, your doctor will consider your overall health condition and advise and/or treat you accordingly. The main objective is to ensure that your risk of heart attack is reduced and your heart disease does not progress to a significant late disease stage.

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 Do I need a referral from my doctor to get a Heartscan ?

You can ask your family doctor to do a cardiac assessment on you to determine your cardiac risk, ie whether you are in the low, intermediate or high risk category. You can also come directly to our centre whereby you will be seen by our specialist cardiologist. Our consultant will be able to advise you on whichever scan you will need.

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The information contained in this website is not a substitute for medical advice or treatment or replaces consultation with your doctor.

 

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Last modified: April 09, 2010