What Causes Palpitations After Taking Thyronorm?

Dear Sir, My intial TSH was 61 a month back, then took eyuthroid 350 mcg once a week but changed my doc who prescribed me thyonorm 100mcg dail but after having it i felt very uncomfortable and palpations in Heart, ultimately am on Thyonorm 50mcg, The latest TSH level is 31 and antibodies is also high 104.