Chest Pain / Suspected ACS

Chest pain is one of the most common and high-stakes presentations during medical on-call in the NHS.

Your job is not to diagnose everything immediately — your job is to:

  • recognise possible Acute Coronary Syndrome (ACS)
  • assess risk quickly
  • start safe early management
  • escalate appropriately

Most mistakes happen in the first 30 minutes, not later.

What counts as suspected ACS?

ACS includes:

  • STEMI
  • NSTEMI
  • Unstable angina

Think ACS whenever chest pain could be cardiac until proven otherwise.

Typical presentations (but remember — many are atypical)

Classic symptoms

  • Central chest pressure/tightness
  • Radiation to arm, jaw, or back
  • Associated sweating
  • Nausea or vomiting
  • Shortness of breath

High-risk atypical presentations (common in NHS wards)

  • Elderly patients with confusion
  • Diabetics with minimal pain
  • Isolated breathlessness
  • Collapse or syncope
  • Epigastric discomfort

If risk factors exist → think cardiac first.

First priority = A–E assessment

Before ECG interpretation or troponins:

Assess stability.

Check:

  • Airway
  • Breathing (RR, sats)
  • Circulation (BP, HR, perfusion)
  • Conscious level
  • Pain severity

Red flags

  • Hypotension
  • Ongoing severe pain
  • Pulmonary oedema
  • Arrhythmia
  • Reduced consciousness

Unstable patient = senior help immediately.

Immediate actions (what SHO should do first)

Do simultaneously, not sequentially.

1. ECG within 10 minutes

This is the most important investigation.

Repeat ECG if pain continues.

2. Monitoring

  • Cardiac monitor
  • BP
  • Oxygen saturation

3. IV access

  • 1–2 cannulas

4. Bloods

  • Troponin
  • FBC
  • U&E
  • CRP
  • Coagulation
  • Lipids (optional early)

5. Initial treatment (if ACS suspected)

Unless contraindicated:

  • Aspirin 300 mg stat
  • GTN (if BP allows)
  • Analgesia (usually morphine if severe)
  • Oxygen ONLY if sats <94%

Do NOT give oxygen routinely.

ECG: what you are looking for

STEMI features

  • ST elevation in contiguous leads
  • New LBBB with symptoms
  • Posterior MI changes

👉 This is a call cardiology immediately situation.

NSTEMI / high-risk ECG changes

  • ST depression
  • T-wave inversion
  • Dynamic changes

Needs urgent review and admission pathway.

Troponin — common misunderstanding

Troponin confirms myocardial injury, not always MI.

Raised troponin can occur in:

  • Sepsis
  • PE
  • Tachyarrhythmia
  • Renal failure
  • Heart failure

Always interpret with:
👉 symptoms + ECG + clinical picture.

Never treat numbers alone.

STEMI pathway (know this cold)

If STEMI suspected:

  1. Call cardiology immediately
  2. Activate PPCI pathway
  3. Do NOT delay for blood results
  4. Prepare transfer to cath lab

Time = myocardium.

NSTEMI pathway (typical NHS practice)

  • Admit to monitored bed
  • Serial troponins
  • Start ACS protocol
  • Cardiology review within 24 hrs

Often includes:

  • dual antiplatelet therapy
  • anticoagulation
  • risk stratification

When to escalate urgently

Escalate if:

  • Persistent chest pain
  • ECG changes evolving
  • Haemodynamic instability
  • Arrhythmia
  • Heart failure signs
  • Diagnostic uncertainty

Never sit on unclear chest pain overnight.

Common on-call mistakes

  • Waiting for troponin before acting
  • Not repeating ECGs
  • Missing atypical ACS
  • Giving oxygen unnecessarily
  • Not escalating early
  • Anchoring on “musculoskeletal pain” too early

Chest pain earns respect.

Practical ward mindset

You are not expected to diagnose perfectly.

You are expected to:

  • recognise risk
  • treat early
  • escalate safely
  • document clearly

Good early management saves myocardium.

Take-home concept

Chest pain assessment is about risk recognition, not certainty.

If ACS is possible:
👉 act early, monitor closely, and escalate.