I've been on Armour for a few months now - and have gradually increased the dose, but I'm not happy with the balance of it. If T3 'in range' T4 is really low and if T4 is 'in range' T3 is too high. I am really worried about any strain on my heart as it seems stupidly sensitive to everything (food, stress, meds, viruses) and I get loads of palpitations - ectopic beats/racing etc. So I really need the balance to be perfect. Is it a problem to go back to Levothyroxine? How should I do it?