Heart problems

Radiotherapy to the left side of your chest might mean your heart receives a small amount of radiation. This is because the heart is on the left side. This can cause some side effects. 

The heart is sensitive to radiation. You might be at a higher risk if you have had heart problems in the past or at the moment. 

Radiotherapy is more accurate than it has ever been so the chance of your heart getting irradiated is lowered. Also if you're having treatment on the left side you might hold your breath at certain points of treatment, so that the heart is moved out of the radiation treatment area (field). This is call deep inspiration breath hold (DIBH). 

Radiotherapy is also carefully planned so that if the heart has to be in the field, only a small part of it will be. 

You always have to let your doctor know if you have or have had any heart problems. And you must always tell them if you have a pacemaker. 

Risk of heart side effects depends on: 

- how much treatment you're having 
- type of radiotherapy

Side effects can include: 

• pericardial effusion. This is when fluid builds up around the heart. This can cause breathlessness. If this happens, you may need a procedure to drain the fluid.

Breathing technique

You might need to hold your breath at times during the treatment if you have radiotherapy to your left breast or the lymph nodes behind the breast bone. This is to protect your heart from the radiotherapy.

The radiographer talks to you over a speaker. They tell you when to hold your breath. It could last up to 20 seconds and they may ask you to do several breath holds. This technique is called deep inspiration breath hold (DIBH).