Heart problems that can appear years after chemotherapy

Yes, some cancer treatments can affect the heart, and in some people problems appear years after treatment has finished. The medicines most strongly linked with late heart effects are anthracyclines, such as doxorubicin, epirubicin and daunorubicin, which can gradually weaken the heart muscle. Trastuzumab, used for some breast and stomach cancers, can reduce heart pumping strength, usually during or soon after treatment and often reversibly, but it adds to risk when combined with anthracyclines. Radiotherapy to the chest, for example for lymphoma or left-sided breast cancer, can affect heart valves, blood vessels and the lining of the heart many years later. Some other medicines, including fluorouracil, capecitabine and several targeted treatments, can affect the heart or blood pressure, usually closer to the time of treatment.

Not everyone who received these treatments develops heart problems, and for most people the benefit of cancer treatment far outweighs the risk. Risk is higher with larger total amounts of anthracyclines, combined chest radiotherapy, treatment in childhood or at an older age, and existing heart risk factors such as high blood pressure, diabetes, high cholesterol, smoking, obesity or a previous heart condition. People treated as children or young adults may develop heart weakness decades later, which is why childhood survivors are advised to have heart checks throughout life.

Heart effects can often be found before symptoms appear. Depending on your treatment and risks, your team may recommend an echocardiogram, an ultrasound scan of the heart, at intervals they decide, along with blood pressure, cholesterol and sugar checks. If heart weakness is found early, heart medicines prescribed by a cardiologist and lifestyle changes can help protect the heart. Knowing which treatments you received, reporting symptoms such as breathlessness, swollen ankles or palpitations promptly, and looking after your general heart health are the most important steps. This page explains the general picture; your doctors can assess your personal risk.

Know which treatments you had

Anthracyclines, trastuzumab and chest radiotherapy are the main ones to note.

Checks can find problems early

Heart scans may detect weakness before symptoms appear.

Protect your heart

Control blood pressure, sugar and cholesterol, and avoid tobacco.

It cannot tell you your personal risk of heart problems, or which checks you need. That depends on your treatment, age and health, and your oncologist or cardiologist will advise.

It also cannot interpret heart scan results. Ask your doctors to explain what your results mean.

Why damage can appear late

Anthracyclines can injure heart muscle cells during treatment. The heart may compensate for years, but as it ages or faces extra strain, such as high blood pressure, pregnancy, infection or weight gain, the weakness can become apparent. This is why heart checks may continue long after treatment.

Pregnancy after anthracyclines

Pregnancy places extra demand on the heart. Women who received anthracyclines or chest radiotherapy may be advised to have a heart scan before or early in pregnancy.

Exercise and the heart

Regular moderate exercise is good for heart health. If you had heart-affecting treatment, ask whether a check is advised before starting vigorous exercise.

Radiotherapy and heart vessels

People who had chest radiotherapy may have a higher risk of narrowed heart arteries years later. Reporting chest pain and controlling cholesterol are especially important.

Medicines that protect the heart

If heart weakness is found, a cardiologist may prescribe heart medicines. These decisions are individual, and you should never start or change such medicines on your own.

Telling future doctors

Tell any doctor who treats you, including emergency staff, dentists and anaesthetists, which cancer treatments you received.

Heart checks for childhood survivors

People treated for cancer as children with anthracyclines or chest radiotherapy are usually advised to have heart scans at intervals throughout life, as heart weakness can appear decades later. The frequency depends on the total amount received and other risks, and is set by their long-term follow-up team.

Blood tests that help

Blood tests such as troponin and natriuretic peptides can sometimes help detect heart strain. They are used alongside scans rather than replacing them, and your doctor decides whether they are useful for you.

Managing risk factors

Keeping blood pressure, sugar and cholesterol well controlled reduces strain on the heart. Your family doctor can check these regularly and prescribe treatment if needed.

Heart rhythm problems

Some people develop irregular heart rhythms after cancer treatment. Palpitations, dizziness or fainting should be reported so an ECG or heart monitor can be arranged.

Heart valves and radiotherapy

Radiotherapy to the chest can cause gradual thickening of heart valves many years later. A heart murmur found on examination, or breathlessness, may prompt a scan.

Future cancer treatment

If you ever need further cancer treatment, tell your oncologist about previous anthracyclines or chest radiotherapy, as it affects which medicines are suitable.

Emotional impact

Learning about heart risks after cancer can cause worry. Understanding that checks can find problems early, and focusing on heart-healthy habits, can help.

Keeping a heart record

Keep copies of heart scan reports alongside your treatment summary, so any change over time can be compared by future doctors.

What to do next

Find out whether your treatment affects heart risk, ask about long-term heart checks, control blood pressure, sugar and cholesterol, stay active, avoid tobacco, report breathlessness, swelling or palpitations, and keep your treatment records.