Why heart pains sometimes, while paining my heartrate is high, plz tell me some possible resons?

Panic attack, Costochondritis, Asthma, Pulmonary embolism, Congestive heart failure or maybe overdoing exercise or physical activity. If it continues, maybe you should see your doctor about it. It's probably not something serious, but there's always a chance that it might be. With any problems concerning the heart, its best to get it checked out by a professional. Hope all goes well.