We do not give medical advice but we list below a few tips which you may find helpful.
Do not ignore chest pain.  Stop what you are doing and rest.  Use your GTN spray (or one tablet under your tongue).  Wait 5 minutes.  If pain persists, then use GTN again and wait a further 5 minutes.  If the pain still persists then dial 999.  Remain calm and ensure the Ambulance Crew can gain entry to your home.  PLEASE NOTE: this is revised advice from NICE & BHF to change from 3 uses of GTN to 2 uses only before dialing 999.
GTN: Always keep it to hand.  If you are with others, whether at home or out with friends, always inform at least one other person where to find it should the need arise.
Medical history and Medication: There may become a time when you are in need of medical assistance.  The professional will be able to make a more informed decision if they know your medical background and what medication you currently take.  Can you remember what drugs you take and the dose?  Most of us cannot, so we have a solution.  
Fill in this card and keep it close to hand.  It will save time and stress when discussing health matters, particularly with members of the Medical profession.