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Arab Board Family Medicine Clinical study materials
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Chest Pain at 2 a.m. in a Rural Clinic

Arab Board Family Medicine Clinical · Put your knowledge to work in context.

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Chest Pain at 2 a.m. in a Rural Clinic

You are the sole family physician on call at a rural health centre 90 minutes by road from the nearest hospital with a catheterisation lab. A 58-year-old man with diabetes and hypertension presents at 02:00 with 45 minutes of central crushing chest pain radiating to the left arm, sweating, and nausea. BP 150/92, HR 96, SpO2 96% on room air, afebrile. ECG shows 2 mm ST elevation in leads II, III and aVF with reciprocal depression in I and aVL. There is no thrombolysis contraindication on history. The ambulance is available but the road is foggy. The clinic has aspirin, clopidogrel, heparin, a defibrillator, and a thrombolytic agent.

1. What is the diagnosis and what is your immediate priority sequence in the first 10 minutes?

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Diagnosis: Acute inferior ST-elevation myocardial infarction (STEMI).

First 10 minutes - parallel, not sequential:

  1. ABC and monitoring - continuous cardiac monitor and defibrillator pads on; IV access; oxygen only if SpO2 <90% (it is 96%, so not indicated).
  2. Aspirin 300 mg chewed immediately (unless true allergy).
  3. Antiplatelet/anticoagulation per protocol - clopidogrel loading and heparin as per local STEMI pathway.
  4. Analgesia - cautious opioid for pain and to reduce sympathetic drive.
  5. 12-lead ECG repeated and note the time of symptom onset.
  6. Call the receiving PCI centre now - activate the reperfusion decision pathway; do not wait to 'stabilise first'.
  7. Right-sided and posterior leads - inferior MI can involve the right ventricle; check for RV involvement (hypotension with nitrates would be a red flag, so avoid nitrates if RV infarction suspected).

The critical exam point: in inferior MI, watch for bradyarrhythmia and heart block and avoid nitrates if RV involvement is present.

2. Given the 90-minute transfer and fog, how do you decide between immediate thrombolysis and transfer for primary PCI? Justify with the time logic.

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This is a time-to-reperfusion decision, not a preference.

The rule: Primary PCI is preferred if it can be delivered within 120 minutes of first medical contact (including transfer). If expected PCI delay exceeds 120 minutes and symptoms began within 12 hours, give thrombolysis unless contraindicated, then transfer for rescue/routine angiography.

Apply the numbers:

  • Transfer is 90 minutes by road in good conditions; with fog and 02:00 activation, realistic door-to-balloon is likely >120 minutes.
  • Symptom onset 45 minutes ago - well within the 12-hour window, so thrombolysis is fully indicated.
  • Therefore: give thrombolysis now (door-to-needle should be <30 minutes), then arrange transfer regardless.

Caveats to state:

  • Confirm no contraindication (recent stroke, bleeding, aortic dissection, severe uncontrolled hypertension).
  • Inferior MI carries a higher risk of bradyarrhythmia and hypotension during reperfusion - monitor closely.
  • Reperfusion success is judged by pain resolution, ST-segment resolution, and reperfusion arrhythmias at 60-90 minutes; failure mandates urgent rescue PCI.
  • Transfer the patient even if thrombolysis appears successful, for angiography.

Document the time-based reasoning explicitly - examiners look for the 120-minute threshold and the 12-hour window.

3. Two hours later the patient develops bradycardia at 42 bpm with BP 88/50 and feels faint. What is happening and how do you manage it?

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What is happening: Likely reperfusion bradyarrhythmia and/or inferior MI with right ventricular involvement and AV node ischaemia - the right coronary artery supplies the AV node in most people, so inferior MI commonly causes sinus bradycardia and heart block. The hypotension with bradycardia fits this picture.

Management, stepwise:

  1. ABC, monitor, IV access, confirm the rhythm on ECG; look for AV block.
  2. Atropine 0.5 mg IV, repeat up to 3 mg total, for symptomatic bradycardia with hypotension.
  3. If atropine fails: transcutaneous pacing (the defibrillator has pacing capability) and/or chronotropic support per protocol; involve the receiving centre.
  4. Fluid challenge cautiously - if RV infarction is suspected, a small fluid bolus can help preload, but be alert for pulmonary oedema.
  5. Avoid nitrates - they can precipitate profound hypotension in RV infarction.
  6. Escalate transfer urgency - this is now a haemodynamically compromised patient needing PCI/cardiology input.

Safety-net: continuous monitoring until transfer; document rhythm strips. This tests recognition that inferior MI is not just 'the ECG' but a haemodynamic syndrome.