I hav hypothyroid since 8 years it is in normal value & taking thyroxine75 mg tablet.In October 2020 I am covid positive my bp is normal 120/80but heart beat is 120- 135.i consult cardiologist ecg &echo are normal sinus trachycardia mentioned doctor suggest do yoga meditation I done it  3 months but no relief I hav chest pain and icant walk 1km.again I consult cardiologist ecg &echo done its normal.doctor prescribed ciplar lr 20mg tablet for 3 months.after 1 month taking this tablet from yesterday's my heart beat 66-78 its normal? heart beat below69 perminute  is normal?in this pandamic situation I cant go to hospital.can I continue this tablet in same dose or decrease dose by consulting doctor.please suggest me.