I had my thyroid removed 6 months ago due to hyperthyrodism.  I have a history of cardiomegaly, afib, high blood preassure and other arythmias.  I am 43 years old, female and my doctors assumed my heart condition was due to my thyroid condition.  Ive had a cardioversion done after the surgery and it worked for about a week.  I am on Amiadorone 200mg twice a day, Atenolol 50mg once a day, Levothyroxine 137mc once a day.  I was on coumadine for 3 months after surgery but not now. After six months my afib has returned with a vengence.  I feel like my doctors are taking my age for granted and my concerns are not being taken seriously.  When I spend a day doing normal activities I get a night of blood pressure 156/108 and a resting heart rate of 180.  I feel like an 80 year old.  Please advice.
You need to see you doctor again to discuss increasing the dose of amiodarone or switching to another antiarrhythmic. Unfortunately, it does not sound like it has been completely beneficially for you. I would recommend getting electrophysiologist studies and an ablation. Ablation is for patient that are resistant or refractory to medication. It is a complex procedure. There are also surgical procedures that are very effective and efficient at controlling Fib. You also need to take an aspirin. The bottom line is that your Fib is not controlled appropriately - you need a medication adjustment or some type of intervention. I would also recommend getting your thyroid levels rechecked.