Heart tests and cancer treatment

Your doctors may use different tests to check how well your heart is working before, during and after your cancer treatment. How often you have tests depends on the type of treatment and whether you already have heart problems.

Your cancer doctor or nurse will explain any tests that you need. Some people find it helpful to have a relative or friend come with them to the test.

You can find more information and videos of people having heart tests on the British Heart Foundation website.

Blood tests

Blood tests help check how well your heart is working. They are also used to monitor the effects of any heart medicines you take.

The most common blood tests used to check heart health are:

  • Cardiac enzyme tests (including troponin test) – These can help show whether your heart muscle has been damaged.
  • Natriuretic peptide tests (BNP or NT-proBNP) – These can help show whether you have heart failure. A high level may be a sign of heart failure. If the level is high, you will need further tests such as a heart ultrasound (an echocardiogram).
  • Urea and electrolytes (U&E) tests – These give information about the levels of sodium and potassium in your blood. Sodium and potassium are important for the function of your heart. U&Es also show how well your kidneys are working. Your kidneys may be affected by any medicines you are taking.
  • Full blood count (FBC) – This test measures the number of different types of blood cells in your blood – red cells, white cells and platelets. It also measures the level of haemoglobin (Hb) in your blood. Haemoglobin carries oxygen around the body.
  • Cholesterol blood tests – Having too much cholesterol in your blood increases the risk of heart problems. If your cholesterol level is high, you can make changes to your lifestyle that can help reduce it. Your doctor may also suggest that you take a cholesterol-lowering medicine.

Electrocardiogram (ECG)

This test:

  • records the electrical activity of the heart
  • measures the heart’s rate and rhythm detects heart rhythm problems
  • sometimes shows if someone has had a heart attack in the past
  • can show if the heart is enlarged or thickened.

Small sticky pads (electrodes) are placed on your chest, arms and legs. Wires connect the pads to an ECG recording machine. This picks up the electrical signals that make your heart beat. The electrical activity is recorded and printed on paper.

The test takes about five minutes and is painless. You need to lie still during the ECG, as moving can affect the results.

24-hour ECG

An ECG can also be recorded over 24 to 48 hours. This is also called Holter monitoring or ambulatory ECG monitoring.

You have electrodes put on your chest. The wires attached to these will be taped down. The wires go under your clothes to a small portable recorder on a belt around your waist.

While you are wearing the ECG recorder, you can do everything you would normally do except have a bath or shower.

When the test is finished, you return the recorder to the hospital. Your doctor will check the results.

Exercise ECG

The aim of this test is to see how your heart works when you are more active. It is sometimes called a stress test. An ECG is recorded while you are walking on a treadmill or cycling on an exercise bike.


This test:

  • looks inside your coronary arteries to find out if any of them are narrowed, and how severe the narrowing is
  • gives information about how effectively your heart is pumping
  • gives information about the blood pressure inside your heart.

You will be asked not to eat or drink anything for several hours before your angiogram.

Having an angiogram

You will have a local anaesthetic injection to numb the skin in your groin or on your arm. The doctor then makes a small cut. They insert a thin, flexible tube called a catheter into an artery. Using x-ray, the catheter is guided to the heart.

The doctor will inject dye into the catheter and take x-rays. You might feel a hot, flushing sensation from the dye. Tell your doctor if you feel uncomfortable or unwell at any time.

Ultrasound of the heart (echocardiogram)

An echocardiogram (echo) uses sound waves to build up a detailed picture of your heart. It is like the ultrasound scan used during pregnancy. It gives information about:

  • the structure of the heart
  • the heart valves
  • how well the heart is pumping.

You will be asked to lie down. When you are comfortable, some gel is rubbed on your chest.

A probe is then placed over different areas of your chest. This probe gives off pulses of sound waves, which echo against the structures of the heart. These echoes are picked up by the probe. They are shown as pictures on the screen of the echo machine.

The test can take from 15 to 60 minutes. It is painless, but it may cause some discomfort if you have had recent surgery on your chest. Your doctor can give you painkillers to help with this.

Trans-oesophageal echocardiogram (TOE)

Some people will have a trans-oesophageal echocardiogram (TOE). This test takes more detailed pictures of the heart from inside the gullet (oesophagus).

The gullet is the tube that connects your mouth to your stomach. It lies behind your heart. This means a TOE can get a closer and clearer picture of the heart valves.

Before you have a TOE, you may be given drugs to make you feel sleepy (sedation). Your doctor will gently pass a small, flexible ultrasound probe through your mouth and into the throat. You will then be asked to swallow. The test usually takes around 20 minutes. It can feel uncomfortable, but it should not be painful. You can usually go home after the sedation has worn off.

CT heart scan

A CT scan takes a series of x-rays, which build up a three-dimensional picture of the inside of the body. It can be used to look at the structure and the pumping action of your heart.

A CT coronary angiogram is a type of CT scan that helps show the blood flow through the coronary arteries.

Having a CT of your heart

Before a CT scan, you may be given a tablet or injection of a drug that slows your heartbeat slightly. A slower heartbeat makes it easier to get clear scans. You will also have a dye injected into a vein in your arm. This dye helps show how blood is moving through the heart.

You lie on a bed which is moved inside the scanner. The scanner is shaped like a large doughnut.

A small amount of radiation is used during a CT scan. If you are pregnant, talk to your doctor before having this test.

Cardiac MRI scan (CMR)

An MRI scan uses magnetism to build up detailed pictures of areas of your body. A cardiac MRI scan gives information about:

  • the structure of the heart
  • the heart valves
  • how well the heart is pumping.

Before a cardiac MRI scan

The scanner is a powerful magnet, so you may be asked to complete and sign a checklist to make sure it is safe for you. The checklist asks about any metal implants you may have.

These could include a pacemaker, surgical clips, bone pins, artificial joints or artificial heart valves, nerve stimulators or a cochlear implant. It is safe to have an MRI if you have coronary stents in place.

You should also tell your doctor if you have ever worked with metal or in the metal industry. This is because very tiny fragments of metal can sometimes lodge in the body.

Having metal in your body does not always mean you cannot have an MRI scan. Your doctor and radiographer will decide if the MRI scan is safe for you. If you are not able to have an MRI scan, another type of scan can be used.

Some tattoo ink contains traces of metal. Most tattoos are safe. But tell the radiographer immediately if you feel any discomfort or heat in your tattoo during the MRI scan.

Before the scan, you will be asked to remove any metal belongings including jewellery.

How is a heart MRI scan done?

For some cardiac MRIs, the doctor will inject a dye into a vein in the arm. This does not usually cause discomfort. The dye helps to give a clearer picture of the heart muscle and the blood flow through and around the heart. Your doctor can tell you more about this.

During the test you will lie very still on a couch inside a long cylinder (tube) for up to an hour. It is painless but can be slightly uncomfortable, and some people feel a bit claustrophobic.

If you are worried about this, tell your doctor before having the scan. You may be offered a mild sedative drug to help you relax.

The scanner is also noisy, but you will be given earplugs or headphones. You can hear, and speak to, the person operating the scanner.

Myocardial perfusion scan

A myocardial perfusion scan shows how well the heart is pumping and looks at the flow of blood to the heart muscle.

It may be used to check for heart changes caused by some types of chemotherapy or targeted therapy treatment.

Having a myocardial perfusion scan

During the scan, your doctor will give you an injection of a small amount of radioactive dye.

A special camera then takes images of your heart. This measures how the dye is pumped through your heart. The scan may be done while you are resting and during exercise on a treadmill or exercise bike.

After a myocardial perfusion scan

You may be asked to avoid close contact with children and pregnant women for a few hours after. If you are pregnant or breastfeeding, talk to your doctor before having this test.

24-hour ambulatory blood pressure monitor

Some cancer drugs can cause high blood pressure. Your cancer doctor or nurse will check your blood pressure regularly. But sometimes they may want to monitor it over a longer time.

This can be done with a portable (ambulatory) blood pressure monitor.

Wearing a blood pressure monitor

You wear it for 24 hours while you continue most of your normal routines. You should not have a bath or shower.

A blood pressure cuff (a band) is wrapped around your upper arm. A tube goes from the cuff, under your clothes, to a small monitor on a belt around your waist.

The cuff inflates around your arm and records your blood pressure. It does this automatically at regular times. For example, it could happen every 30 minutes during the day and every hour at night. The monitor records your blood pressure measurements and the time they were taken.

After 24 hours, the monitor is removed. The information is collected for your doctor to check.

About this information

Our information about heart health and cancer was developed in partnership with the British Heart Foundation.

If you have questions about your heart health, call the Heart Helpline on 0300 330 3311, Monday to Friday, 9am to 5pm, or visit bhf.org.uk.

Date reviewed

Reviewed: 01 February 2019
Next review: 01 February 2022

This content is currently being reviewed. New information will be coming soon.

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