What Causes Sudden Onset Of High Heart Rate?

I was sitting at my bed watching video at my computer and eating chips with salsa, suddenly I felt my heart rate go up ( like that fluttering feeling middle of chest) then I decided to walk to the dinning table and check my blood pressure 112/67 and what alarmed me was the 112 pulse rate. I have been having these episodes quite frequently. Is that normal ? Should I go to the doctor to have that checked? Thanks