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Cardiac CT Scans: What to expect & how to prepare

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You’re here because your doctor may have referred you or a loved one for a cardiac CT Scan, and you want to know more about the procedure, to put your, and their mind at ease.

Computed Tomography, also known as a CAT Scan or CT Imaging, uses X-ray images taken from different angles to build a comprehensive 3-dimensional picture of your heart and blood vessels. Once the scan is complete, your results are then assessed by a radiologist before being sent to your attending physician.

It’s a relatively straightforward procedure, but to help you prepare accordingly, we’ve put together vital information you need to know. Read the blog below.

What is a cardiac CT scan?

A cardiac CT scan is a non-invasive imaging test that uses X-ray technology to create detailed 3D images of the heart and its surrounding blood vessels. 

Doctors use CT scans to look for anomalies and diagnose heart conditions, such as coronary artery disease, blockages in the heart’s blood vessels, and heart valve problems. 

They’re also used as an alternative to invasive procedures such as cardiac catheterisation, which involves threading a catheter through a blood vessel and to the heart.

How can you prepare for it?

Typically, the clinic will contact you before your cardiac CT scan to discuss what to expect and how to prepare.

If you’re pregnant, please inform the clinic before your appointment. A Computed Tomography Scan exposes you to mild radiation, which isn’t good for the baby.

If it’s absolutely necessary that you have the scan, you’ll be given a lead apron to shield your pelvis and abdomen.

You may also be asked to:

  1. Fast for four hours before the scan: Depending on the test being performed, you may need to fast to ensure your stomach is empty. The clinic will give you specific instructions on how long too fast for, and what you can and can’t eat or drink.
  2. Avoid caffeine (coffee, tea, and energy drinks) and tobacco: These can affect your heart rate and blood pressure, so rather save it until after the scan.
  3. Wear comfortable clothing: While you will be asked to change into a hospital gown for the scan, it’s still a good idea to wear loose, comfortable clothing that’s easy to change in and out of.
  4. Remove metal objects and jewellery such as earrings, watches, and glasses: These can interfere with the scan, so it’s best to take them off or leave them at home.
    It’s vital that you discuss any medical conditions and medications you’re taking with your doctor before the scan.

For example, if you suffer from kidney disease or diabetes, your doctor may want to adjust your medication prior to the scan or take special precautions to minimise potential risks.

Learn all about CT Scans here.

When are you referred for a cardiac CT scan?

Do you have a family history of heart disease?
Is your blood pressure unusually high?
Would you say you struggle with high cholesterol?
Have you been experiencing heart palpitations, shortness of breath, or chest pain of late?

Your doctor may refer you for a cardiac CT scan as a precautionary measure. But they might also refer you if they suspect you have a heart condition, such as coronary artery disease.

A Cardiac CT scan can be used to

  • Evaluate the effectiveness of treatments for heart conditions, such as coronary artery bypass surgery or stenting.
  • Assess your heart valves and aorta, and check for problems such as an aneurysm.
  • Determine whether you have a congenital heart problem that may have been undiagnosed since birth.
  • Check for plaque build-up and blockages around the arteries or narrowing.
  • Determine if you have a tumour around your heart.
  • Plan for procedures such as a transcatheter valve or minimally invasive heart surgery.

What are the risks?

There is a small risk of radiation exposure during a cardiac CT scan, but it’s very low, and the benefits of the test outweigh the risks.

There’s a chance you’ll experience an allergic reaction to the contrast dye, which contains iodine. This can lead to itching, sneezing, feeling nauseous, or breaking out in a rash. In this circumstance, you’ll be monitored by the clinic’s staff and given an antihistamine.

If you’re breastfeeding, you’ll need to wait at least 24 hours after ingesting the contrast dye before feeding your baby, as the dye can make its way into your milk. It’s best to pump and dump during this time.

What happens during the scan?

During the scan, you’ll be asked to lie down on a narrow table that slides into a tube-shaped machine called a CT scanner.

Once the procedure starts and the scanner rotates the centre of the ring around your body, you’ll need to stay very still to avoid the images blurring. To help you maintain your position, ask for a pillow.

Don’t be alarmed if you hear whirring or buzzing noises. This is completely normal. Just try to relax.

What happens after the scan?

Once the cardiac CT scan is complete, you’ll be allowed to return to the changing rooms to remove your hospital gown and retrieve your jewellery.

You can eat, drink and resume your normal activities.

If contrast dye was used during the scan, you’d be advised to drink plenty of fluids to help flush the dye out of your kidneys.

Your results will be reviewed by the attending radiologist and made available to your referring doctor or specialist shortly after. If you’ve not heard back from your physician within 48 hours of completing the procedure, please call them for an update.

If you experience an adverse reaction to the contrast dye, please avoid strenuous exercise for a day or two to reduce your risk of complications. Further, if you experience severe pain or shortness of breath after the scan, contact your doctor immediately.

How long does the scan take?

The actual scan doesn’t take long — usually 10 or so minutes. It’s all the prep work leading up to the scan, making sure you’re positioned correctly, and reviewing the images that can take time. 

We advise between one and two hours from arriving at the hospital until you’re given the all-clear to go home. 

Some patients have been known to react badly to the contrast dye. In this case, the clinic will provide you with medication, two days prior to the scan to avoid a reaction occurring on the day of the examination.

How is a CT Scan different from an Angiogram Scan?

A cardiac CT scan is usually performed on outpatients and doesn’t require sedation or anaesthesia. It also has fewer risks.

An angiogram, also called a cardiac catheterisation or coronary angiogram, is an invasive test done in a Catheterization Laboratory, that involves threading a thin, flexible tube (called a catheter) through a blood vessel in your groin or arm and into your heart. 

Contrast dye is then injected through the catheter, and X-ray images are taken as the dye flows through your heart’s blood vessels. 

You’re typically sedated for an angiogram the test. As a result, you may need to book an overnight stay for observation.

While both tests can provide detailed images of the heart and its blood vessels, an angiogramprovides detailed information regarding the blockage or narrowing of the blood vessels. If immediate treatment is required, a stent can be placed into the artery wall. Doctors recommend an angiogram if you have a confirmed severe blockage in your coronary arteries. 

That said, there is a greater risk of complications, such as bleeding or damage to the blood vessels. The choice of test will depend on your medical history and the specific clinical situation.

Book your scan with ERAD

Now that you know what to expect, are you ready to book your cardiac CT Scan?

Book an appointment online and visit our main ERAD branch in Walvis Bay.

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