Hello and thank you for using HCM. I carefully read you question and I understand your concern. I will try to explain you something. There are different reasons that might cause increased heart beats. Physical or emotional stress,alcohol, caffeine products might cause increased heart frequency. You say that you don t use coffee and this is a good thing. Your addiction with opiates might be the reason of fast and hard heart beats. If you are in a period that you are trying to leave them it is quite comprehensive to feel this fast heart beats, palpitations, atypical pains and anxiety. All this symptoms are normal in an abstinence period from opiates. It might last a little wile so you should not worry and be strong, it will pas. All sow, there are different pathologyes like anemia, thyroid gland problems like hyperthyroidism that might be the cause of fast heart beats. When you experience a high frequency, it might be normal to experience palpitation, chest-arm discomfort. So i thing that is it nothing to worry about. If these frequencies are interfering in your normal daily live, If I was your treating doctor I will recommend some simple examinations. I will recommend an electrocardiogram, a cardiac echocardiography and of course a rhythm holter monitoring for 24 h. This is necessary to have a full view of your mean frequencies during day and night. After these, a full blood chek up to exclude anemia or thyroid problems. Doing this examinations helps us understand if it is necessary to treat this rapid heart beat or no. Hope I was helpful. Wish you good health. Best regards.