Reasoning GP · Algorithm · 1-page summary
Acute chest pain in adults
For: adults with new or recent chest pain, face to face or remote, in hours or OOH. Not for: children, major trauma or sickle-cell disease (use their own pathways). Pregnancy, postpartum and active cancer go straight to block 2.
Core rule: time since the last pain sets the urgency (CG95). A normal ECG, chest-wall tenderness, relief with GTN, young age or an anxious patient excludes nothing. If you are still worried, escalate.
0Stop — call 999 now — before any history
- Cardiac-sounding pain now, or within 12 hours with an abnormal or unavailable ECG → 999 whatever the observations.
- Sudden tearing pain, maximal at onset, to the back; pulse deficit, arm-to-arm BP difference or new neurology (aortic dissection) → 999
- Unstable: collapse, systolic BP <90, pulse >120 or <40, new SpO₂ <94%, RR ≥30, falling GCS; silent hemithorax or tracheal deviation; raised JVP with hypotension → 999
- While waiting: aspirin 300 mg for suspected ACS (not if allergic, and withhold if dissection is possible); write onset time, dose and time on the handover. Oxygen only if SpO₂ <94%. Do not delay transfer for an ECG, bloods or a fuller history.
1Triage by time — since the last episode (CG95)
| Last pain | Action |
|---|---|
| Now | Possible cardiac features → 999 |
| <12 h, pain-free | ECG abnormal or not available → 999. ECG normal → Same-day hospital |
| 12–72 h | Same-day hospital |
| >72 h | Full assessment and ECG; troponin via the local pathway. Do not relabel it stable angina. |
2Screen — one row is enough
- PE: pleuritic pain with breathlessness, pulse >100, haemoptysis, leg swelling, risk factors → Same-day. Wells >4 → CTPA via the acute route, not a GP D-dimer.
- Pneumonia or sepsis: CRB65 ≥2 → consider hospital; sepsis → 999
- Pericarditis (worse lying flat, eased sitting forward, rub) → Same-day hospital
- GI: rigidity, haematemesis or melaena, pain after forceful vomiting → Same-day surgical
- Pregnant or ≤6 weeks postpartum, cancer, anticoagulated, immunosuppressed → Same-day maternity / acute. No D-dimer in pregnancy.
- Aged 40+, unexplained chest pain plus another unexplained symptom, or ever smoked or asbestos → CXR within 2 weeks (NG12)
3Assess — only once blocks 0–2 are answered
☐ BP both arms, pulse, RR, SpO₂, temperature ☐ JVP, heart sounds, chest, trachea, calves, epigastrium, skin (zoster) ☐ 12-lead ECG if pain is present or recent, without delaying transfer
Troponin goes through the local acute pathway. Not in primary care: exercise ECG, or GTN as a diagnostic test.
4Classify — only if the screen is negative
- Angina — 3 features (typical) or 2 (atypical): constricting pain in chest, neck, jaw or arms · brought on by exertion · relieved by rest or GTN within ~5 min → rapid access chest pain clinic.
- Non-anginal — 0–1 features, normal ECG and observations. Name the alternative; ECG changes → refer as angina.
- Musculoskeletal — localised and reproducible. Supports, never excludes.
- Reflux — burning after meals or lying flat. Dysphagia, weight loss, haematemesis → NG12 upper GI.
- Panic — only after cardiac and lung causes are dealt with.
- Uncertain — say so. Do not default to "MSK", "reflux" or "anxiety"; name who reviews and when.
5Treat today — only these
- Suspected ACS: aspirin 300 mg once, even if on low-dose aspirin; withhold if dissection is possible.
- Oxygen: only if SpO₂ <94% (target 94–98%; 88–92% if at risk of hypercapnia).
- Known stable angina, usual attack: GTN spray, repeat after 5 min; still pain 5 min later → 999. No GTN within 24 h of sildenafil or vardenafil, or 48 h of tadalafil.
- Every other serious cause: transfer is the treatment.
6Refer routinely
- Suspected stable angina → rapid access chest pain clinic (CT coronary angiography).
- Known angina uncontrolled on 2 anti-anginals → cardiology.
- Reflux after 8 weeks of PPI, no NG12 features → gastroenterology. Recurrent panic → NHS Talking Therapies.
7Never reassure by
- Relief with GTN, an antacid or analgesia.
- Chest-wall tenderness.
- A normal ECG, SpO₂ or set of observations.
- Young age, female sex, or an anxious patient.
- A reassuring score when you are still worried.
- A remote assessment with no observations or ECG.
8Safety-net — say it, then document it
999 “Call 999 — don't drive — for chest pain that is there now, comes at rest, lasts over 15 minutes, or comes with breathlessness, sweating, sickness, collapse, or pain spreading to the arm, jaw or back.” Same day: “Pain on less effort than before, new breathlessness, coughing blood, a swollen painful leg or black stools — contact us today.”
Remote or OOH: convert to face-to-face or 999 if pain is present during the call, the timing is unclear, observations or an ECG cannot be obtained, or the pain is exertional with risk factors. The patient never drives themselves.
✓Safe to leave primary care only if — all five, documented
No block 0–2 row applies
Observations normal; ECG normal if pain recent
One cause explains the whole pain, or uncertainty stated
CV and VTE risk recorded; referral or review owner and date set
Safety-net given; patient not driving
Summary of the full Reasoning GP chest pain algorithm, which holds the detail, examination, scores and evidence. Sources: NICE CG95, NG185, CG126, NG158, NG250, NG253, NG136, NG12 (updated April 2026); BTS emergency oxygen; MHRA. Clinical reference — follow local emergency-transfer policies and check doses in the SPC and your local formulary.