Cardiac CT

Cardiac CT: Info & Get a Scan

If you’ve been experiencing heart problems or suspect you might be, a CT scan can help get the diagnosis and reassurance you need. Doctors can use CT scan images to assess the structure of your heart and the health of the surrounding blood vessels in a fast and non-invasive manner.

As CT scans use ionising radiation, our expert clinical team will make sure a CT scan is the correct option for your individual requirements. As part of your booking with us, you’ll receive a 1-1 clinician consultation, so that our team can medically justify your scan and provide a fast referral to get you the answers you’re looking for.

What is a CT scan of the heart (Cardiac CT)?

A cardiac CT scan uses X-rays to generate images of your heart and the surrounding blood vessels. CT differs from a traditional X-ray scan as it creates more detailed images across multiple ‘slices,’ which can be merged into a 3D image, or viewed as a series of 2D images to pinpoint the exact source of a heart abnormality.

There are different types of cardiac CT scans, with a range of diagnostic procedures offered based on the reason for the scan. If the scan is designed to highlight the arteries that transport blood to the heart, you may hear it referred to as a coronary CT angiogram. If the scan’s purpose is to identify calcium buildup in your heart, it might be called a coronary calcium scan.

Before the scan, you might be given medication to slow your heart rate, or a contrast agent IV - both are used to enable clearer imaging. During the scan, you’ll lie on a flat bed, and sticky electrode patches are applied to the skin of your chest.

The flat bed is moved into the doughnut-shaped scanner, so that it surrounds your chest. The scanner circles around you, and an X-ray beam is directed at your heart from different angles. Detectors on the other side of the scanner will measure the amount of radiation passing through the different tissues of your heart. A computer uses this data to compile images.

Types of Cardiac CT Scan

There are three main types of cardiac CT scan, and the right one depends on the question your clinician is trying to answer:

• Coronary CT angiogram (CCTA) - Uses contrast dye to show the arteries supplying your heart in fine detail. It’s the standard test for investigating chest pain and suspected coronary artery disease.
• Calcium score CT - A shorter scan with no contrast dye that measures calcium buildup in your artery walls. The result is a score estimating your future risk of heart disease, which makes a calcium score test a common choice for people with risk factors but no symptom
• Structural cardiac CT - Assesses the heart’s chambers, valves and the aorta. It’s often used to plan procedures such as valve replacement or to check for complications afterwards.

Your clinician will confirm which type you need during your pre-scan consultation.

What does a CT scan of the heart show?

CT scans of the heart can detect and diagnose a variety of health concerns very quickly. They can show the coronary arteries supplying blood to your heart, the heart’s structures such as valves and chambers, and the sac (pericardium) around your heart.

CT scans of the heart can identify narrowing or buildup in the arteries, problems with the heart valve function, birth defects and congenital heart problems, tumours, and high levels of calcium in the heart that could be an indicator of coronary artery disease.

Why Might I Need a Cardiac CT Scan?

A cardiac CT scan is most often used to investigate chest pain, and to find out whether the arteries supplying your heart have narrowed. NHS trusts list this as the most common reason for the scan. Other reasons include:

• Symptoms such as unexplained chest pain, breathlessness or palpitations
• An inconclusive result from a stress test or another heart investigation
• A family history of heart disease, where you want to understand your own risk
• Assessing your heart valves, or checking the aorta for aneurysms or tears
• Planning a procedure such as a valve replacement, or checking for complications after one

You don’t need a GP referral to book with us. Every booking includes a consultation with one of our clinicians, who will confirm whether a cardiac CT is the right test for your symptoms and history.

What a Cardiac CT Scan Can Diagnose

Cardiac computed tomography scans are a low-risk procedure used to diagnose various conditions affecting the heart arteries and the heart chambers, and to discover the reason for chest pain. Your doctor will use the results from such cardiac scans along with blood test results to diagnose, or rule out, the following:

• Congenital Heart Disease - Congenital heart disease develops when a baby is still in the womb, causing them to be born with a heart defect. 
• Birth Defects - A cardiac CT scan is used to detect defects in the hearts of babies and young children who are displaying signs of heart problems. 
• Blood Clots - A blood clot in the heart can be caused by smoking, high blood pressure and high cholesterol, and reduces blood flow to the heart, which can eventually lead to a heart attack. 
• Heart Valve Disease - Heart valve disease causes narrowing, blockages and leaking in the valves of the heart that can lead to restricted blood flow and potentially heart failure. 
• Tumours - A cardiac CT scan will detect the presence of tumours in the heart, which are either cancerous or non-cancerous. 
• Pericardial Disease - Pericardial disease, or pericarditis, causes inflammation of the lining of the heart, called the pericardium, causing chest pain that may spread to your left shoulder and arm.
• Aneurysms - An aortic aneurysm is a bulge in the aorta that carries oxygen-rich blood from the heart to the rest of the body, caused by a weakening in the wall of the blood vessel. Aortic aneurysms are often linked to high blood pressure. 
• Heart Failure - Heart failure means that the heart is struggling to pump blood around the body, and is often associated with high blood pressure as well as other heart conditions. A cardiac CT scan will detect heart failure and its causes, allowing doctors to create a treatment plan. 
• High Calcium Score - A high calcium score is a buildup of calcium deposits in the heart arteries. It’s an indication that there’s a buildup of plaque in the arteries, which can lead to coronary artery disease. 
• Coronary Artery Disease - Coronary artery disease is caused by a buildup of plaque and fatty cholesterol deposits in the arteries that can cause high blood pressure and eventually lead to heart failure. 
• Damage to Heart Chambers - The heart chambers can be damaged, thickened, stretched or stiffened due to previous heart attacks, disease of the heart muscle or high blood pressure. This will affect its ability to pump blood around the body, potentially leading to heart failure and a heart attack.
• Previous Heart Attack - A cardiac CT scan can detect if you’ve previously had a mild heart attack that you may not have known about. 

Do I need a cardiac CT scan with contrast?

Usually, a contrast agent is required for a CT scan of the heart. This is an iodine-based substance, usually administered into the bloodstream via an IV (intravenous) line in your arm. It helps to highlight the blood vessels and distinguish between different tissues in your images. The substance is flushed from your kidneys naturally after the scan, so it’s recommended to drink extra fluids.

After placing your booking for a cardiac CT scan, you’ll receive a clinician consultation with a member of our expert healthcare team. They’ll explain if you need a contrast agent, and will make sure it’s safe for you to have one administered.

If you have kidney problems like kidney disease or have recently had an adverse or allergic reaction to a contrast agent, this could affect your suitability, but our medical team will always suggest alternative scans as required.

When a Cardiac CT Scan Might Not Be Suitable

Cardiac CT works well for most people, but there are situations where it may not give clear images, or where another test is safer:

• A very fast or irregular heartbeat. The scan is timed to your heart rhythm, so conditions such as atrial fibrillation can blur the images. Beta blockers can slow a fast rate, but they don’t suit everyone.
• Heavy calcium buildup. Large amounts of calcium in the artery walls can make it harder to judge how narrow an artery is, and further tests may be needed to confirm the result.
• Kidney problems. The contrast dye is cleared through the kidneys, so reduced kidney function may rule it out. If you’re over 60 or have known kidney disease, a blood test to check kidney function may be needed first.
• Contrast allergy. A previous reaction to contrast dye, or an allergy to iodine, needs discussing before the scan.
• Pregnancy. Scans are usually avoided during pregnancy unless clinically essential.

None of these automatically rules you out. Your pre-scan consultation exists to catch them: our clinicians will review your history and suggest an alternative, such as a cardiac MRI, if a CT isn’t the right option for you.

How to Prepare for a Cardiac CT Scan

Preparation for a cardiac CT scan is simple, and your clinician will confirm any specific instructions when you book. In general:

• Avoid caffeine for 12 hours before your scan - Tea, coffee, chocolate, cola and energy drinks all raise your heart rate, which can blur the images. NHS guidance also advises avoiding these on the day of the scan itself.
• Drink plenty of water - Being well hydrated makes the cannula easier to place and helps your kidneys flush out the contrast agent afterwards.
• Take your regular medication as normal - unless your clinician tells you otherwise. Bring a list of everything you take. If you have diabetes and take metformin, mention this at your consultation, as it sometimes needs to be paused around contrast scans.
• Avoid smoking and nicotine on the day of your scan - Like caffeine, nicotine raises your heart rate.
• Wear loose, metal-free clothing - so staff can easily reach your upper arm and chest.

Tell your clinician if you take medication for erectile dysfunction such as sildenafil (Viagra). These drugs cannot be combined with the GTN spray that is sometimes used during the scan, so your appointment may need adjusting.

The Procedure Explained: What to Expect

CT imaging of the heart is a noninvasive test that's quick and painless and carried out in the radiology department of your hospital or clinic. It does come with small risks associated with radiation exposure, but these will be discussed with you. Here's what to expect on the day:

1. Getting ready - You may be asked to change into a medical gown, for your own comfort and to ensure you’re not wearing anything metallic that could interfere with the images taken.
2. Heart rate check - If your heart rate is above around 60 beats per minute, you may be given a beta blocker to slow it down, and sometimes a GTN spray under the tongue to widen your coronary arteries. Both improve image quality and wear off quickly.
3. Contrast dye, if needed - If you’re having a contrast dye administered (that creates clearer images of the blood vessels), this will be given intravenously through a vein in your arm.
4. The scan itself - The CT scanner will move around your chest as you lay on your back on a medical table. You may be asked to hold your breath for a few seconds while the images are taken.

A note on contrast dyes: the contrast dyes used can cause a potentially life threatening reaction in some people, particularly those who have advanced kidney problems. If you have problems with your kidney function or you have a known allergy to contrast dyes, let your doctor know. Symptoms of an allergic reaction include feeling breathless, weak and sweaty. Inform your radiologist immediately if you begin to feel unwell. Contrast dyes may also cause a metallic taste in the mouth, but this dissipates quickly.

If you’re pregnant: cardiac CT scans are usually avoided during pregnancy unless clinically essential, as X-rays can be harmful to an unborn baby. Tell the team if you are, or think you might be, pregnant, so they can discuss your options with you.

How long does a cardiac CT scan take?

CT scans can be completed very quickly - the whole body can be scanned in under a minute. However, your appointment may be up to 30 minutes long, to allow time for getting changed, setting up the contrast agent IV (if required), filling in any paperwork on-site, and discussing any questions you might have.

What to wear for a CT scan of the heart (cardiac CT)?

Metal items can affect the quality of your CT scan images, so it is recommended that you leave any jewellery, belts and watches at home. Glasses, dentures, hairpins and some hearing aids may also need to be removed for your scan.

If you wear soft, comfortable clothing, you may be permitted to stay in your own clothes for your cardiac CT scan. However, you might be asked to change into a medical gown, to allow application of electrodes or if the clothing you arrive in is unsuitable for the scan.

What Happens After a Cardiac CT Scan?

Once your radiographer is happy that they have the right images, you’ll be able to get up from the CT scanner and get dressed. Most patients can go home and carry out their normal activities the same day.

If you had a contrast dye cardiac CT scan, you’ll be asked to remain in the clinic for 30 minutes following your scan, to ensure that you don’t begin to develop an allergic reaction.

If you were given a beta blocker, you may feel tired for a short while afterwards. NHS advice is to arrange a lift home or wait in the department until the effects have settled before driving.

Getting the Results

Your radiologist and referring doctor will assess your results before contacting you within a few days to discuss them with you. They will discuss treatments, ranging from lifestyle advice to medications such as beta blockers to help lower your blood pressure and potential surgery. 

What is the difference between a cardiac CT scan and MRI of the heart?

Depending on the reason for getting a scan of your heart, an MRI scan could be a better method for providing the diagnosis you’re looking for.

MRI scans usually take longer than CT scans, and are noisier and more enclosed, but they don’t use radiation and can be done without a contrast agent. CT scans are quicker, quieter, and less enclosed, so can be better suited for claustrophobic patients.

If you’ve received advice from your doctor or consultant that a CT scan is right for you, or if you’re seeking a scan independently, our expert clinical team can verify whether the scan is the right option for you once you’ve placed your booking.

How much does a cardiac (heart) CT scan cost?

Our cardiac CT scan prices start from £650. The price you pay upfront covers a complete package of care, which includes:

• A pre-scan consultation with a dedicated expert clinician to discuss your symptoms and requirements
• A fast referral to your chosen scanning centre, with no GP visits and no waiting lists
• Your scan, at a convenient location near you
• A radiologist’s report of your results
• Access to your scan images upon request
• A post-scan consultation with your clinician if any next steps are required

Next Steps:

• Book a private cardiac (heart) CT scan today, to fast-track your diagnosis and get the answers you need
• Visit our news page to find out more about CT scans and the other types of scan we offer, including CT vs MRI guides

FAQs

Is a cardiac CT scan safe?

Yes, for most people. The scan uses a low dose of ionising radiation, kept as low as possible by modern scanners. NHS trusts compare the dose to the natural background radiation you would receive over roughly one to three years of everyday life in the UK. Your clinician will weigh this small risk against the value of the information the scan provides. Tell the team if you are or might be pregnant.

Is a cardiac CT scan better than an angiogram?

They do different jobs. A cardiac CT is non-invasive and needs no recovery time, while a traditional coronary angiogram involves threading a catheter through your blood vessels. NICE guidance recommends CT coronary angiography as the first-line investigation for new stable chest pain, and a clear scan can rule out coronary artery disease with a very high degree of accuracy. Invasive angiography is usually reserved for cases where treatment such as stenting may be needed.

Can I drive after a cardiac CT scan?

Usually, yes. If you were given a beta blocker to slow your heart rate, you may feel tired for a short while, so arrange a lift home or wait in the clinic until the effects wear off.

Can I eat and drink before a cardiac CT scan?

You can usually drink water freely, and staying hydrated is encouraged. Avoid caffeine for 12 hours before the scan, and follow any fasting instructions given at your pre-scan consultation.

Sources used:

Royal Free London NHS Foundation Trust. Having a cardiac CT scan. https://www.royalfree.nhs.uk/patients-and-visitors/patient-information-leaflets/having-a-cardiac-ct-scan

Oxford University Hospitals NHS Foundation Trust. Cardiac Computed Tomography (CT). https://www.ouh.nhs.uk/cardiac/services/cardiology/investigations/ct/

National Institute for Health and Care Excellence. Chest pain of recent onset: assessment and diagnosis (CG95). https://www.nice.org.uk/guidance/cg95

Gloucestershire Hospitals NHS Foundation Trust. Adult patients having a CT scan of the heart. https://www.gloshospitals.nhs.uk/your-visit/patient-information-leaflets/adult-patients-having-ct-scan-heart-ghpi1435_10_18/

University Hospitals Plymouth NHS Trust. Cardiac CT Scan. https://www.plymouthhospitals.nhs.uk/display-pil/pil-cardiac-ct-scan-7556

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