I Was Taking .125 Of Levothyroxine And A TSH Test

I was taking .125 of Levothyroxine and a TSH test showed I should take a higher dose. i was bumped up to .150 and immediately began have heart flutters and pounding. After three weeks, my doctor told me to stop taking it for 4 days and then switch to .137. I did but the feelings persisted. An EKG showed I have PVC. My doctor told me to stop my meds for 7 days and the resume the .137. If the symptoms don't stop, what would be the next step. And is it likely the result of a too-high dosage that brought this on in the first place?