If you experience chest pain it is not appropriate for the Doctor to treat this by either seeing you in surgery or visiting you at home. This is not because they will not do so, it is because being treated quickly is safer and has more success than waiting for a GP visit.
If a patient contacts the surgery and is experiencing chest pain, they will be asked to speak to a Doctor or Nurse straight away who can then make the decision whether the patient should ring 999 or not. In the rare event that a clinician is not available on the premises, the receptionists are trained to follow a strict protocol.
It is much better for you, the patient, to ring 999 as it is essential the Ambulance Service is informed of any deterioration whilst you are waiting for the ambulance to arrive.
If a patient already has a history of heart problems and is experiencing chest pain, they should NOT contact the surgery in the first instance, but should ring 999 immediately.