I Am A Thyroid Cancer Patient With Removal Of 90

I am a thyroid cancer patient with removal of 90 percent of throat and replaced with flap from right thigh. I am on suppression dosage of synthroid and cytomel. I was diagnosed with SVT September 2014. I have been treated with dilitizam. The last two weeks I have had irregular heart beat and continual burping. I monitor blood pressure as I am treated for that with losartan. I feel palpations, indigestion, heartburn and burping. BP runs 135 over 84 and sometimes more and sometimes less. Most of time heartbeat is 96-122. Today my heartbeat ran 56-97. After taking meds it ran 56-69 for couple hours. I just had EKG 6 weeks ago. Was normal. Any idea what is going on? Thank you.