Actually, the doctor was experimenting with taking me off levothyroxine to see if it would make my afib go away or lessen the incidents because I was on a low dose. She said that the generic thyroid meds (for low thyroid) had inconsistent doses and sometimes were too much and sometimes too little. I don't know if going off the med lessened my symptoms because that was early on when I was having a lot of symptoms. My triggers actually seem to be getting very tired or getting anxious or getting dehydrated. I got home this week from a trip and had several afib incidents on it because I was getting too tired and the plane trips especially made me anxious and it's hard to get enough water when you travel.
My doc will put me back on thyroid meds again if my next blood test shows my thyroid is low again. Then we'll see again if I'm affected or not.
After much reflection on this, I am sure I initially got afib from a combination of stress, some alcohol (I did not get drunk–had only two glasses), acid reflux, and bronchitis when I sometimes have a hard time breathing. My heart acted like it was starving for oxygen.