Should i be worried if my resting heart rate is suddenly between 50-60bpm? i do feel a bit out of breath, and heart is fluttering a bit. i have been diagnosed with atrial fibrilation before due to hypothyroidism, and was on verahexal for 6 months?

Check thyroid levels: Your pulse rate is not necessarily a problem, but could be a sign of low thyroid function, or less likely, presentation of a mild cardiac dysrhthmia in view of your history. Since this is complex, urge you contact your doctor, have thyroid blood studies and an updated EKG, at the least.

Heart rate 50-60: You don't mention what your usual resting heart rate is. If 50-60, which occurs in many healthy young adults,is a distinct decrease from your usual rates, it could be the development of sick sinus syndrome.or bradycardia-tachycardia syndrome in view of your prior history of A Fib. A Fib is more commonly caused by hyperthyroidism rather than hypothyroidism. See Cardiologist, wear heart monitor