Would make sure you are not on too much thyroid medication -- excessive thyroid hormone (from the thyroid itself or from medications) can cause heart palpitations and possibly atrial fibrillation which increases the risk of stroke. You need to look at your TSH level to make sure it is in the normal range. A cardiology evaluation may also be appropriate to make sure there is not a problem with the heart as it may have nothing to do with your history of thyroid disease.
Yes, I had nuclear test, Heart Monitor for 24 hrs. and angiogram 4 years ago. Said everything looked fine. Since then I have had tsh, lipids, and electrocardiogram yearly. should I have a cardiologist exam again?