Hi - I have been reading some of the questions on this web site - it's such a relief to read that there's other folks with these awful scary heart palpitations. I've just been diagnosed with Hypothyroidism - it all started with heart palpitations, I was starting to think I had a heart problem. Doctor took bloods and ECG, said heart was fine - thyroid was normal to low - it took him ages to give me Levothyroxine, I started off taking 50 mcg now it's been put up to 75 mcg - heart palpitations are less frequent, but I'm easily tired. I seem to have gone from a really fit person, that enjoyed hill walking, dancing and gardening - to this, every time I dance or walk up a hill, the palpitations start - I keep thinking that I'm really fine today, then all of a sudden these palpitations start again, it's so scary!! Anyway thanks for this web site, it's so comforting to know that I'm not alone!!! Do you think that these palpitations or irregular heart beat has all to do with Hypothyroidism? I've also been put onto Propranolol for the irregular heartbeat - This is all so new to me taking medication - I never used to take anything other than vitamins and healthy diet!!