How cancer treatments can affect your heart

Some cancer treatments can affect how your heart works. This may cause heart problems that are short term (temporary) or long term (permanent). Problems may develop during or soon after cancer treatment, or they may develop many years later.

The risk of heart problems depends on the type of cancer treatment and how much treatment you have.

Your risk may be higher if:

  • you have other risk factors for heart problems
  • you had a heart problem before starting cancer treatment
  • you have several cancer treatments at the same time.

Your cancer doctor will explain if a cancer treatment is likely to affect your heart. If you are worried about heart problems, ask them for more information. 

Treatments for cancer include:

  • radiotherapy
  • drugs such as chemotherapy, targeted therapy or hormonal therapy
  • surgery.

If your treatment has finished and you are worried about your heart, talk to your GP.

How can cancer treatments affect your heart?

Some cancer treatments can affect how your heart works. This may cause heart problems that are either short term (temporary) or long term (permanent). Problems may develop during or soon after cancer treatment, or they may develop many years later.

The risk of heart problems depends on the type of cancer treatment and how much treatment you have.

Your risk may be higher if:

Your cancer doctor will explain if a cancer treatment is likely to affect your heart. If you are worried about heart problems, ask them for more information.

If your treatment has finished and you are worried about your heart, talk to your GP. Sometimes it is hard to remember the details of your cancer treatment. Your cancer doctor or your GP can give you more information and answer any questions you have.

If you had cancer treatment as a child, you may have a higher risk of developing heart problems as an adult. This depends on the type of cancer treatment you had. Some people will have regular follow-up appointments for the rest of their life to check their heart health.


Radiotherapy

Most people who have radiotherapy do not develop heart problems after treatment. Radiotherapy is only likely to cause heart problems if the heart is in the area that is being treated, such as radiotherapy for breast cancer in the left breast. If you have radiotherapy to another part of your body, it is unlikely to damage the heart.

Radiotherapy techniques are becoming more accurate. Treatment can usually be carefully planned to avoid affecting the heart. This means heart problems after radiotherapy are becoming less common.

Radiotherapy to the heart can:

  • affect the coronary arteries, which can lead to coronary heart disease
  • damage the heart muscle
  • damage the heart valves.

After radiotherapy

Heart problems can sometimes develop five or more years after radiotherapy treatment.

If you had radiotherapy which you were told may affect your heart, you can still improve your heart health by making healthy lifestyle choices.

Your GP may arrange regular appointments after cancer treatment to check for signs of heart problems. At the appointments, you may have:

  • your blood pressure checked
  • a blood test taken to check your cholesterol levels
  • a scan to check how your heart is working.

If you notice any warning signs of heart problems, tell a doctor as soon as possible.


Chemotherapy

Some types of chemotherapy may cause heart problems. If you are taking several cancer drugs together or having chemotherapy with chest radiotherapy, the risk can be higher.

Your cancer doctor will explain any risks before you start chemotherapy. Different drugs can cause different problems:

  • Some drugs are only likely to cause heart problems if you have a high dose. Your cancer doctor will plan your treatment carefully and record the doses you are given.
  • Some may cause heart changes during or shortly after you have treatment.
  • Some drugs can cause heart problems many years later.

Some chemotherapy drugs are given into a vein (intravenously) with large amounts of fluid. If you already have a heart condition, this can put pressure on your heart and may cause problems. Your nurse will monitor you for any signs of problems while you have these treatments.

Before treatment, you may have blood tests and a scan to monitor how your heart is working. For some types of chemotherapy, you will have these tests again during and after your treatment, to look for early signs of heart muscle damage. You may not have any symptoms, but it is important to treat early signs to stop further damage.

Sometimes chemotherapy causes symptoms that need urgent treatment to prevent serious problems. Tell your doctor or nurse straight away if you have:

  • chest tightness, pain or discomfort
  • pain that spreads to your shoulders, neck, jaw or arms
  • shortness of breath
  • blackouts (fainting)
  • dizzy spells
  • palpitations.

If you get any of these symptoms during treatment, your doctors will stop the chemotherapy drug and check your heart. They may change the type of chemotherapy to one that does not cause heart problems.

We have more information about different chemotherapy drugs.

Anthracyclines

Anthracyclines are the most common type of chemotherapy drugs to affect the heart. This includes the drugs:

Many people who have these drugs do not develop any heart problems. But sometimes they can cause heart muscle damage that causes symptoms during, shortly after or years after treatment.

Other chemotherapy drugs

Sometimes other types of chemotherapy drugs can affect the heart. These include:

A small number of people may develop heart problems within hours to a few days of these treatments. This includes:

  • symptoms of heart failure
  • abnormal heart rhythms (arrhythmia)
  • rarely, a heart attack.


Targeted therapies

Targeted therapy drugs (also called biological therapies) are used to treat many different cancers. Some of these drugs can affect the heart.

Different drugs can cause different heart problems. Some may cause high blood pressure or abnormal heart rhythms. Others can cause symptoms of angina or heart failure.

If you want to know more about a targeted therapy drug you are taking, ask your cancer doctor. They can give you information about possible effects on your heart.

Some of the most common drugs that may affect the heart include:

We have more information about targeted therapy drugs.

Researchers are still looking at the effect some newer drugs have on heart health. Your cancer doctor will talk to you about possible risks before you start any treatment. They will give you advice about any symptoms and may arrange tests to check your heart before, during and after treatment.


Hormonal therapies

These drugs are often used to treat breast cancer or prostate cancer. Sometimes they are used to treat other types of cancer.

Hormonal therapies do not usually damage the heart directly, but they can affect your risk factors for heart problems. They may raise your blood pressure or cholesterol levels. People also tend to gain weight while taking hormonal therapies. This can increase your risk of developing diabetes and heart problems.

If you are taking a hormonal therapy, you can reduce these risks by making healthy lifestyle changes. Your doctor may also suggest treatments for high blood pressure or high cholesterol.

We have more information about hormonal therapy drugs.


Surgery

Surgery is one of the main treatments for cancer. Sometimes surgery can put the heart under stress and cause heart problems. Having surgery with a general anaesthetic (drugs that keep you asleep) may also cause heart problems for some people.

If you have a healthy heart, surgery is not usually a problem. But there may be a higher risk of damage to the heart for people who:

  • had heart problems before surgery
  • have diabetes
  • are over 70 years old
  • have high blood pressure.

If you have minor surgery and only need to be asleep (anaesthetised) for a short time, the risk may be small. If you have major surgery and need to be asleep for several hours, the risk can be greater.

Your doctor will talk to you about the possible risks of your surgery. Before you have a general anaesthetic, you will have tests to check your heart and make sure you are fit enough for surgery. If you have a high risk of serious heart problems, your doctors may suggest other cancer treatments you can have.

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Back to Cancer treatment and your heart

Tests to check heart health

There are several tests your doctors can use to check your heart function before, during and after treatment.