Been ill since August, saw electro physiologist last week who says I either have AF or IST....inappropriate Sinus Tachycardia. So my heart beats all the time at 110 plus at resting, shooting much higher with exhersion. So have been house bound and unable to go to work. Can anyone tell me if there is a test/procedure to see which condition I have? Either one it is my heart beating too fast. Been given Bisoprol which has lowered heart beat but also lowered BP so still constantly exhausted.