Acute coronary syndrome

Global core

Prolonged ischemic pain is assessed with an ECG immediately. ST-segment elevation is a reperfusion emergency. Aspirin is offered early unless there is a clear allergy or another true reason not to give it. The loading dose, the second antiplatelet, and the minute limit that chooses primary PCI over fibrinolysis are set locally.

What stays the same

• A 12-lead ECG comes before a planned stress test.
• ST elevation with ongoing pain is a reperfusion problem.
• Aspirin is offered early unless there is a true reason not to give it.
• Troponin confirms injury. It must not delay reperfusion the ECG has already justified.

1. Recognize. Crushing or pressure-like pain, sweat, nausea, or sudden breathlessness.
2. Reason. The ECG sorts ST elevation from other acute coronary patterns. Troponin confirms injury but must not delay reperfusion when the ECG already shows ST elevation.
3. Prioritize. Shock, pulmonary edema, and a malignant rhythm outrank a planned stress test.
4. Act safely. Monitor, give aspirin if safe, and move the patient along the local reperfusion path.

Local adaptation

• United Kingdom

  NICE NG185 recommends a 300 mg aspirin loading dose as soon as possible unless there is clear aspirin allergy, and prefers primary PCI when symptoms began within 12 hours and PCI can be delivered within 120 minutes of the time fibrinolysis could have been given.

  NICE. Acute coronary syndromes (NG185) (2020). Accessed 2026-09-29.

• United States

  The 2013 ACCF/AHA STEMI guideline recommends aspirin 162 to 325 mg before primary PCI, and recommends primary PCI when it can be performed in a timely fashion by experienced operators. Later US documents should be checked before treating this dose as current.

  ACCF/AHA. 2013 Guideline for the Management of ST-Elevation Myocardial Infarction (2013). Accessed 2026-09-29.

Exam lens

Next action: ECG and reperfusion, not a next-day treadmill, when the pain is ongoing and the ECG is diagnostic.