I agree with caregiver222 that you must NOT take the prednisone for a fast heart beat.
You should make an appointment to see your doctor to get checked out if there is an underlying heart problem that needs to be dealt with.
The heart rate will increase when running and doing some activities and also when feeling anxious or stressed. If the heart beats very fast for no apparent reason, you would need to contact the emergency services for advice.
Absolutely positively not!