Second Atrial Fibrillation Attack. History Of Radiation To Left Breast Through Back. History Of Being Placed On Diltiazem With First Attack. Is A-fib Related To Radiation?

Perhaps my question is best directed to a radiation oncologist? Not sure.. In any event, I received radiation to my left breast for 6 weeks two years ago. I received the treatments through my back. One year ago, I had an Atrial fibrillation attack and was hospitalized. Now again, this past week another attack, not as severe as the first, but in the ER all night. With the first attack, I was placed on the calcium channel blocker cartia(diltiazem). My question is: Is the A-fib related to the radiation to the left side?. Interesting that it should happen now. I am awaiting further tests with a cardiologist in several days. Is their a relationship?