Metaprolol question?

[Johnnie1234]

Can i take it only when my heart is racing they gave to me in the ER because my heart rate was high and going fast so they gave to me and said want you to see a heart docter i saw the heart docter all result is fine he said my heart is strong it could be Stress related or like they say Anxiety he told me i dont need metaprolol but my heart is always racing even when im laying down i get up my heart is going really fast then i breath in and out it start to relax but slowly but idk it just seem wierd even by moving or getting up or going down some stairs my heart is racing or in a car it could be any where i could feel my heart speeding up or pounding hard on my chest idk was just seeing if anyone been through it . i feel like i get shortness of breath alot sometimes to but docters say im fine. just by touching my chest it hurts a little bit and could really feel my heart right there its scary feeling