Hello. I am 42 year old woman, I was diagnosed with thyrotoxicosis last summer, and have been on a reducing dose of Carbimazole ever since. When first diagnosed had palpitations and ectopic heartbeats and was on a low dose beta blocker, but weaned off after a couple of months and not used for about 6 months now. Still have daily ectopic beats but pulse normal and living normal life. Thyroid meds 5mg carbimazole daily and last 2 bllood tests normal thyroid readings. Last night suddenly without warning became very dizzy when reclining or lying down. Settled if i sat upright or stood. Streams of ectopic heartbeats although pulse rate not high. Went to ER, was there for many hours, during which time if I lay down or reclined the room spin around. They took ECG and did standing/ lying blood pressures where my BP was a little low lying down but still normal range. Dr finally arrived to examine me and during exam the dizziness lifted and I felt normal. Stopoed as fast as it had started, and dr sent me home to see my GP and have a cardiac tape booked. Is this likely to be thyroid levels going haywire again or a coincidental heart rhythmn problem that I need investigating - or something else completely random and not connected at all? Thankyou.