Yeah, it sounds like heart palpatations. Have you had this problem before? For now just take it easy; lie down and relax, maybe have some water. This is most often brought on by stress (and sometimes you may not even feel that stressed, but even a small small thing can set it off) But you should go to your doctor to check to make sure there s not something going on in the larger picture of your health. Has your doctor ever heard a heart murmur? Just tell him/her what happened (and what you were doing before this started). Your doc might want to get an EKG or echocardiogram to check out your heart rate and heart size, shape etc. Don t worry, these are completely painless. I recommend seeing your doctor though, because I have similar problems which are related to a hole in my heart (called Atrial Septal Defect). when in doubt, seek professional help, not yahoo readers