My son has not been feeling well lately, he feels he is having a heart attact. Sweating, nervousness , trembling, and scared. they have told him it is not his heart. He was diagnosed with a-fib 3.5 years ago but that seems to be better until this past weekend... he is checking his heart pressure all the time and it is scaring him and the family; though he has mentioned it in the past months of this sharp pains, now has been more freguent.. thank you