CT CORONARY ANGIOGRAM- An Overview
Computed Tomography (commonly referred to as CT scan) uses a combination of X-ray images with the help of a computer to produce clear images of our body. Your doctor may advise this test if you show any signs of abnormality involving the blood vessels of your lungs, catheter ablation ,brain, kidneys, heart, or any other part of your body.
A CT coronary angiogram is a diagnostic imaging test that produces 3D images of your heart and blood vessels that supply blood to your heart. Your doctor may use the information obtained from this test to know more about your medical condition and also to decide the best course of action to treat you.
Determining the type of CT Angiography needed
While stress testing is the traditional non-invasive approach in detecting coronary artery disease, sometimes this testing could be inconclusive and there might be a strong clinical suspicion of coronary artery disease. Such a situation needs a proper assessment of the coronary artery and this is possible either with catheter-based coronary artery angiography or by non-invasive CT coronary angiogram. A catheter-based coronary angiogram involves a tube to be introduced through the arm or groin to your coronary arteries on your heart. For patients already suffering from coronary artery disease, the doctor may use a traditional coronary angiogram as this may enable the patient to receive treatment as well during the procedure.
Why do I need it?
CT coronary angiogram can identify damaged arteries or veins and detect plaque (fatty/ calcium deposits) in the coronary arteries. A CT angiography provides the doctor with more-accurate images of your blood vessels. This helps you and your doctor discuss a treatment plan if the test suggests any heart problem. Doctors recommend CT angiography for the following few reasons:
- To find clogged blood vessels that is formed by plaque (fatty material) in the walls of arteries
- To find formations of an abnormal blood vessel inside our brain
- To find an enlarged blood vessel that may rupture (aneurysm)
- To find blood clots that could have developed in the leg veins and may have traveled into our lungs
- To detect blood vessels that are damaged by thoracic surgery.
Information obtained from CT angiogram can help in preventing a heart attack or stroke.
Any risks involved?
It carries a small amount of risk as the test is often invasive in nature and you will also be exposed to some radiation during this diagnostic test. Pregnant ladies are strictly prohibited from having a CT Angiogram as it may harm the unborn baby. In addition, you may possibly have an allergic reaction to the use of iodinated contrast media (radiographic dye, or ‘dye’ as usually referred to) used in this procedure. Speak to your doctor about your concerns if you think you will have allergic reactions.
How is it performed?
You will be administered with intravenous Iodinated contrast (dye) and as the contrast passes through the coronary arteries it is imaged. The doctor may prescribe some medicines to lower your heart rate prior to the procedure (beta blockers), as higher heart rates may give fuzzy images of your coronary arteries. If there is an allergy to contrast material, a medication may be administered to lower the risk of a reaction.
Electrodes are placed on your chest to record your heart rate. Breath holding for a few seconds may be required during the test. While the entire process may take up to an hour, the scanning actually takes just five seconds. A technician will operate the machine from a room that’s separated from the exam room by a glass window. There will be an intercom system that allows communication with the technician.
Can we Eat/Drink before the test?
Generally, you will be asked to come fasting (at least four hours before the procedure). Caffeinated drinks have to be avoided at least 12 hours before the test as it may increase your heart rate making it difficult to take clear images of your heart. You can drink water though. If you are found allergic to the use of radiographic dye, your doctor may provide medication 12 hours before the test to reduce the risk of reaction.
Can prescribed medicines be taken?
You may also take your prescribed medicines as usual, before your test.
What about Diabetics?
Diabetic patients should take light breakfast or lunch three hours before the scan timing. Following your CT scan, depending on your diabetes insipidus medication, detailed instructions will be provided to you.
What happens after CT angiogram?
After the procedure, once CT angiogram is completed, one can return to normal daily activities. It is advisable to drink plenty of water to help flush the dye from the body.
The results of the test will be discussed by your doctor. Regardless of the results, it is important to make lifestyle changes to help protect your heart – stop smoking, eat heart-healthy foods, exercise regularly, and manage risk factors like diabetes, blood pressure, cholesterol, body weight, stress and above all, get your heart checked periodically. A comprehensive heart screening or a Healthy Heart Package from a healthcare provider near you may help.