Low heart rates after starting Metformin

Hi all!

I have POTS, a RBBB, and Hashimoto’s Thyroiditis. I recently started Metformin ER (500mg once a day) per my endocrinologist due to suspected insulin resistance. I have been keeping up with my liquid IV and electrolyte and sodium intake. I am currently on Day 3 and these have been my symptoms so far:

-Low heart rates -diarrhea every couple hours the first two days (today it has slowed down) -wooziness -fatigue -cramping

Although the diarrhea has gotten a little better, the low heart rates are concerning me. Has anyone else experienced this or have any tips/suggestions/experiences for the low heart rates and diarrhea?