Cancer treatment if you have a heart condition

The heart is a large muscle that pumps blood around the body. The blood delivers oxygen and nutrients around the body and takes away carbon dioxide and waste products.

The heart is divided into 4 main areas, called chambers – 2 on the right and 2 on the left:

• The 2 smaller, upper chambers collect blood going into the heart. These chambers are called the right atrium and the left atrium.
• The 2 larger, lower chambers pump blood out of the heart. These chambers are called the right ventricle and the left ventricle.

The inside of the heart

There are 4 valves inside the heart. They open and close as the heart pumps blood. The valves keep the blood flowing in one direction through the heart.

Blood travels around the body through tubes called blood vessels. The blood going to the heart is low in oxygen. It travels through the heart and is pumped out to the lungs.

In the lungs, the blood picks up oxygen and gets rid of carbon dioxide, which is then breathed out. The blood carrying oxygen travels back through the heart and is pumped out to the body again.

Outside of the heart

Like the rest of the body, the heart needs its own blood supply to bring it oxygen. Small blood vessels on the outside of the heart carry blood and oxygen to the heart muscle. These blood vessels are called coronary arteries.

The heart has its own electrical system that tells it when to beat and pump blood around the body. A group of cells called the sinus node sends an electrical signal through the heart to start each beat. This happens about 60 to 100 times a minute. The sinus node is also called the heart’s natural pacemaker.

Not all cancer treatments are suitable for people with heart problems. But this can depend on the type of heart problem and how well controlled it is. Your cancer doctor or specialist nurse will talk to you about this. If a cancer treatment is likely to cause serious problems, they may suggest a different type of treatment.

Some people have an electrical device placed under the skin near the heart. It is used to treat abnormal heart rhythms. There are 2 types of this device:

• pacemakers
• implantable cardioverter defibrillators (ICDs).

Radiotherapy and some types of scan can affect how these devices work. So it is important to tell your cancer team if you have one. Take any written information or guidance about your device to your radiotherapy pre-treatment appointments and your first radiotherapy treatment appointment. This will help your cancer team to plan any scans and treatment so it does not affect your device. They will also arrange any extra monitoring you need to check your device or change its settings.

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.

We want everyone affected by cancer to feel our information is written for them.

We want our information to be as clear as possible. To do this, we try to:

• use plain English
• explain medical words
• use short sentences
• use illustrations to explain text
• structure the information clearly
• make sure important points are clear.

We use gender-inclusive language and talk to our readers as ‘you’ so that everyone feels included. Where clinically necessary we use the terms ‘men’ and ‘women’ or ‘male’ and ‘female’. For example, we do so when talking about parts of the body or mentioning statistics or research about who is affected.

You can read more about how we produce our information here.