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Radiotherapy to L breast and Paroxysmal Atrial Fibrillation

Posted by

I am expecting radiotherapy after my lumpectomy L upper outer quadrant. I see the oncologist next week.

I am still ,3 weeks after surgery, very bruised. My breast is 75% yellow and brown so still sore but have full arm movement. I am on an anticoagulant ( apixaban) and flecainide for well controlled Paroxysmal Atrial Fibrillation.

I understand radiotherapy sometimes makes arrhythmias more common in the future but as I am being treated am I likely to have issues during treatment. I haven't  had an episode for 6 years and practice meditation and auto hypnosis also. Sorry for the essay

Wendy.  Just breathe
Kate C - Macmillan
Posted by


Thanks for your query. 

Radiotherapy to the left breast does run the risk of damaging the heart, but this risk is very small when compared to the benefit of the treatment.  It is what we call a late effect of treatment, which can appear years after so won't cause a problem during your radiotherapy.  

The treatment can damage the blood vessels that surround the heart a little, so this increases the risk of arrhythmias or cardiac changes several years after treatment which can then cause some issues.  However, treatment techniques nowadays are much improved and planning teams take special care to avoid the heart as much as possible. If you are having your treatment in a centre that uses the breath hold technique, then they will get you to hold your breath for 20 seconds at a time during treatment which will ensure your heart and the surrounding vessels are far away from the treatment field, so not putting you at further risk. 

I hope that's answered your question. 

Best wishes, 


Remember you can also speak with the Macmillan Support Line team of experts. Phone free on 0808 808 0000 (Mon-Fri 9am-5pm) or by email.  

Posted by

thank you. That's a great help.  I do practice slowing my breathing as it helps when I get ectopics or runs of tachycardia but I am used to abdominal breathing so must practice using my intercostals I believe!! 20 seconds sounds a long time. Thanks again

Wendy.  Just breathe