I have had two episodes of heart racing, first time my heart rate was 220 and the second 190. Both times I was given something through i.v to stop and restart my heart. Since the first time I have what feels like fluttering in my heart. I am on Beta Blockers - 5mg once in the morning and 5mg at night. I was on synthroid for my thyroid but the first time I had the racing I was told to stop taking the medicine. The Dr. has now out me on Teva-Gabapentin but it does not seem to be helping either. Help!!