It depends on the rate and symptoms.
If you feel dizzy, very tired, unsteady or has chest pain or palpitation get medical help without delay. Also if rate goes below 40 you SHOULD get medical help.
Meanwhile if possible I would like some additional information from you :
1.What is your heart rate during tachycardia and bradycardia?
2.Do you have any symptoms during tachycardia or bradycardia?
3.Do you have symptoms during exercise?
4.Could you tell me more about your electrophysiology test results?
If possible get an ecg done . It might be helpful
Dr Vivek Mahajan