Let's learn everything about a cardiac CT scan in a simple way.

Have you ever gone to see a doctor because you had chest pain or shortness of breath and they told you to get a CT scan of your heart? You may have been a little scared and curious about what it is, how it is done, and whether it will hurt. Don't worry, today we will talk about the CT scan of your heart, or Cardiac CT scan, in a very simple way. This is a test that actually gives your doctor a lot of valuable information about the health of your heart, and it is not something to be afraid of.

What is a CT scan of the heart?

Simply put, this is a special X-ray test that takes a three-dimensional (3D) picture of your heart. It's like taking many clear pictures of your heart, the major blood vessels that connect to it, and the things around it all at once.

This involves sending several X-ray beams through your body from different angles and combining the data with a computer to create a very clear, detailed 3D image. Sometimes, to make these images even clearer, a special liquid called a contrast dye is injected into a vein in your arm. This liquid makes your blood vessels and parts of your heart stand out better on the scan. This method can produce very clear, high-quality images, even of your beating heart.

What exactly can this scan detect?

The images obtained after this scan will allow your doctor to see many things about your heart. The main ones are:

• Coronary arteries, which supply blood to your heart: These blood vessels can be checked for plaque, blockage, or narrowing.
• Heart chambers, muscle and valves: The size of the heart chambers, the function of the muscles, and whether the valves are working properly can be seen.
• Pulmonary veins: You can see the veins that carry blood from the lungs to the heart.
• Thoracic aorta: This is the main blood vessel that starts at the heart and can be used to check for problems, such as aneurysms or a tear in its wall (dissection).
• Pericardium: The thin membrane surrounding the heart can be examined to see if there is fluid accumulation or if it has thickened (calcification).

In what situations would a doctor tell you to have this scan?

A doctor may recommend this scan when they need to learn more in-depth and clear information about the heart that other tests cannot find. For example:

• Find the exact cause of your chest pain or shortness of breath .
• Check to see if your heart's blood vessels have calcium or fat deposits (plaque) , are narrowed, or blocked.
• Assess how your heart valves are functioning .
• Check for any problems with the aorta , such as aneurysms or dissection .
• Plan ahead for open heart surgery or robotic surgery.
• Design modern treatments, such as transcatheter valve procedures .
• Plan ahead for treatment of an irregular heartbeat (arrhythmia ablation) .
• Check to see if any complications have occurred after the surgeries or treatments mentioned above.
• Find out if you have a congenital heart problem .
• Check for a tumor or mass in or around the heart and identify its nature.
• Check for fluid accumulation or calcium deposits in the pericardium , the sac surrounding the heart.

What is the difference between Cardiac CT and Cardiac MRI?

Many people get these two tests confused. Although both take clear images of the heart, there are some differences between the two. Let's take a look at what they are.

How should you prepare before the scan?

To get the best results from this scan, you need to prepare a little the day before. The hospital will give you instructions on this, but let's go over some general things you need to know.

Things to be careful about when eating and drinking

• On the day of the scan, do not eat anything for four to six hours before the scan. However, you may drink water.
• Do not drink anything containing caffeine the day before and on the day of the scan. This means avoiding coffee, tea, energy drinks, and caffeinated soft drinks completely. Caffeine can increase your heart rate, making it difficult to get a clear image.
• Also , if you are using stimulants (energy or diet pills) , do not take them the day before or on the day of the scan.

Things to remember about medication

• If you have claustrophobia, don't panic. Tell your doctor about it in advance. He or she can give you a sedative to help you relax .
• It is very important to inform your doctor about all medications you are taking (including those you take without a prescription).
• If you are taking medications such as sildenafil (Viagra® or Revatio®) , do not take them the day before or on the day of the scan. This is because they may interact with some medications given during the scan. If you are unsure, ask your doctor.
• If you have diabetes , ask your doctor about how to take your medication on the day of the scan. If you feel your blood sugar level is low, inform the staff immediately.

What to expect on the day of the scan?

Before the scan, the staff will ask you a few questions. It is important that you answer them accurately.

• Are you pregnant ?
• Do you have allergies to iodine or seafood ?
• Are you undergoing radiation therapy ?
• If you are over 60 or have kidney problems , you may need to have a blood test to check your kidney function before the contrast dye is given.

How to prepare yourself for the scan

1. First, you need to remove all your jewelry and put on a special gown provided by the hospital.

2. If you need to slow down your heart rate a bit to get a clearer image, you can give it a medicine.

3. If a contrast dye is to be given, a nurse will insert a small tube (IV line) into a vein in your arm.

4. You will then be made to lie down on a special bed in the middle of the CT machine.

5. Three areas of your chest will be cleaned and three small stickers (electrodes) will be applied. You may also have some hair removed. These electrodes will be connected to an EKG machine that records the electrical activity of your heart.

6. You will need to keep your arms above your head the entire time the scan is being performed. Your head and legs will be outside the machine.

What happens during the scan?

The entire process, including preparation time, can take about 30-60 minutes, but the actual scan takes less than 10 minutes.

• You will feel the bed you are lying on slowly move into the donut-shaped machine.
• When contrast dye is given through an IV, it is normal to feel a slight warmth and a metallic taste in your mouth as it travels through your body. This will go away within a few seconds.
• To get clear images, it's very important that you stay still . If the staff tells you to hold your breath for a moment , do so.

After the scan, you can go home, eat, and do your normal activities. However, if you were given a sedative, you will need someone to drive you home. Your doctor will explain the results of the scan to you either on the same day or in a few days.

Are there any risks with this scan?

A CT scan is a very low-risk test, but some people may have a slight reaction to the contrast dye or other substances used.

• Side effects of contrast dye: Some people may have an allergic reaction to it. Symptoms may include itching, nausea, sneezing, and hives. These usually resolve without treatment. Very rarely, a severe allergic reaction (anaphylactic reaction) that causes difficulty breathing can occur. This can be life-threatening and requires immediate treatment. If you have diabetes or kidney disease, you may be asked to drink extra fluids after the scan to help flush the iodine out of your body. If you are a breastfeeding mother, it is best to express breast milk before the scan and breastfeed your baby for a day or two after the scan, as the dye used for the scan can pass into your breast milk.
• Radiation: CT scans use X-rays. Long-term exposure to these rays may slightly increase your risk of cancer. However, for your safety, the amount of radiation emitted during this test is kept to a minimum. Because X-rays can be harmful to a fetus in the womb, this test is not recommended for pregnant women.

What are the results and what do they mean?

Your doctor will explain to you what is in the report you receive after the scan. In general, there are two types of results.

Finally, don't be afraid of a Cardiac CT scan, or the machine itself. This is a test that provides valuable information about the condition of your heart without making any incisions in your body. For the best results, follow the instructions given by your doctor and hospital staff exactly.