History suggesting unstable cardiac ischaemia
| Cardiac sounding chest pain and any of: |
| • Pain the same as a previous AMI |
| • New onset of rest pain |
| • Pain not relieved by standard treatment in standard time |
| • Pain lasting more than 60 minutes |
| • Pain occurring with increasing frequency over the previous 24 hours |
| • Pain within six weeks of AMI or revascularisation |