heart troubles?

Great, as if the stress of graduating next week was not enough during lunch i fall to the floor, I fainted. Turns out i have a bad habit of not drinking water, and this time it fainally cought up with me and i fainted from dehidration. While i was at the doctors they checked my heart, turns out there is somthing odd with it. A part of my heart moves faster the the rast once inawahile, the doctor said its not serius, than said we should see a proffessional, witch always makes me worry, if im okay, why send me to get it checked out more?