Who this is for: GPs and medical officers who receive walk-in chest pain in clinics without troponin assays, monitored beds or a cath lab, and must decide within minutes between emergency transfer and outpatient workup.

Epidemiology in Pakistan

Ischaemic heart disease is the leading cause of death in Pakistan, and South Asians develop acute coronary syndromes 5 to 10 years earlier than Western populations, frequently in their 40s, driven by diabetes, smoking, hypertension, dyslipidaemia and central obesity. Because ambulance coverage is patchy, a large share of ACS patients present first to a GP clinic or arrive by private car, which makes the OPD ECG and the aspirin tablet genuinely life-saving interventions.

First 10 minutes: the fixed drill

  1. Rapid look: pallor, sweating, distress, vitals in both arms if dissection is plausible.
  2. 12-lead ECG within 10 minutes of arrival for any chest pain that could be cardiac (AHA/ACC 2021 and NICE CG95 both anchor here). A single normal ECG never excludes ACS; repeat in 15 to 30 minutes if pain continues.
  3. If ACS is suspected: chewed aspirin 300 mg (unless true allergy or active major bleeding), keep the patient at rest, secure IV access if you have it, and give sublingual GTN for ongoing ischaemic pain if systolic BP is above 90.
  4. Oxygen only if SpO2 is below 90 to 94 percent; routine oxygen is out.
  5. Call the transfer before perfecting the notes.

STEMI on ECG (ST elevation in two contiguous leads, or new LBBB with a convincing story): time is muscle. Give aspirin 300 mg plus clopidogrel loading (300 mg; 75 mg without loading in patients over 75 where local protocol says so), and transfer immediately to the nearest PCI-capable centre (in major cities, public cardiac institutes run 24-hour primary PCI free or subsidised). Where PCI within 120 minutes is impossible, the receiving hospital pathway is fibrinolysis; your job is the fastest safe transfer, not thrombolysis in an unmonitored clinic.

Sorting the rest: presentation and differentials

Typical ischaemic pain: central pressure or heaviness, exertional, radiating to arm, jaw or back, with autonomic features. Beware atypical presentations in diabetics, women and the elderly: dyspnoea, epigastric pain, or simply feeling unwell. NICE CG95 classifies anginal pain by three features (constricting character, exertional provocation, relief by rest or GTN within 5 minutes): 3 of 3 typical, 2 of 3 atypical, 0 to 1 non-anginal.

Deadly non-ACS differentials to actively exclude: aortic dissection (tearing interscapular pain, pulse or BP asymmetry, new diastolic murmur), pulmonary embolism (pleuritic pain, dyspnoea, tachycardia, risk factors), tension pneumothorax (unilateral silent chest, distress), oesophageal rupture after vomiting. Common benign mimics: GERD, musculoskeletal pain (reproducible tenderness helps but does not exclude ACS), panic attacks, herpes zoster before the rash.

Risk stratification without troponin

Most Pakistani GP clinics cannot run serial troponins, so structure the history instead. The HEART score components (History, ECG, Age, Risk factors, Troponin) still work with the troponin element scored zero or deferred: a patient with a highly suspicious story, ischaemic ECG changes, age over 65 and multiple risk factors is high risk regardless of any blood test, and belongs in hospital today. Conversely, a young patient with reproducible chest wall tenderness, a normal ECG and no risk factors can usually be worked up as an outpatient.

Practical rules for a no-troponin setting:

  • Ongoing or crescendo pain, rest pain within 48 hours, ischaemic ECG changes, haemodynamic upset, syncope or heart failure signs: refer now as suspected ACS.
  • Pain settled, ECG normal, but story typical or patient diabetic or over 65: same-day or next-day referral to a facility that can run troponin (widely available in city labs; high-sensitivity assays in larger centres) and observe.
  • Clearly non-anginal pain, normal ECG, no red flags: treat the likely cause and safety-net explicitly.

For stable-sounding exertional pain that has resolved, arrange outpatient assessment per NICE CG95: resting ECG, haemoglobin, glucose or HbA1c, lipids, and referral for anatomical or functional testing (CT coronary angiography where accessible in major cities, otherwise stress testing at a cardiac centre). Do not order a treadmill test yourself to rule out unstable angina; unstable symptoms are a hospital problem.

Red flags: transfer without delay

ST elevation or new LBBB; ongoing pain despite GTN; hypotension, diaphoresis, or arrhythmia; suspected dissection (do not give aspirin if dissection is seriously suspected); suspected PE with instability; new heart failure; syncope with chest pain. Send a copy of the ECG with the patient and phone ahead; MyPatient AI-prepared intakes attach the ECG image and timeline to the referral note automatically, which spares the receiving registrar ten minutes of reconstruction.

Follow-up schedule

  • Referred-and-discharged patients: review within 1 week with hospital documents; ensure aspirin, statin, and other secondary prevention started in hospital are continued and titrated.
  • Non-cardiac pain: review at 2 to 4 weeks; reassess if the pattern becomes exertional.
  • Every chest pain visit is a risk-factor visit: BP, glucose or HbA1c, lipids, smoking cessation counselling, weight.
  • Give every discharged patient a written safety net: return immediately for pain over 15 minutes unrelieved by rest or GTN. Share the patient guide to share.

Key points

  • ECG within 10 minutes for all potentially cardiac chest pain; repeat if pain persists.
  • Chewed aspirin 300 mg for suspected ACS unless contraindicated; add clopidogrel loading for STEMI transfer.
  • A normal single ECG does not exclude ACS; the story and risk profile decide referral.
  • Actively consider dissection, PE and pneumothorax before labelling pain non-cardiac.
  • No troponin on site means a lower referral threshold, not a longer observation.
  • Every discharge carries written safety-netting and a risk-factor plan.

References

  • Chest Pain of Recent Onset: Assessment and Diagnosis, CG95. National Institute for Health and Care Excellence, 2010 (updated 2016).
  • 2021 AHA/ACC/ASE/CHEST/SAEM/SCCT/SCMR Guideline for the Evaluation and Diagnosis of Chest Pain. American Heart Association and American College of Cardiology, 2021.
  • 2023 ESC Guidelines for the Management of Acute Coronary Syndromes. European Society of Cardiology, 2023.
  • Third Universal Definition and subsequent Fourth Universal Definition of Myocardial Infarction. ESC/ACC/AHA/WHF Task Force, 2018.
  • HEART Score for Chest Pain Patients: validation studies summary. Backus et al, International Journal of Cardiology, 2013.

Clinical judgement and local protocols take precedence.