❤️ CardiologyCardiovascularStudentInternResident

Acute Coronary Syndrome (incl. STEMI)

Also known as: heart attack · myocardial infarction · MI · STEMI · NSTEMI · unstable angina

Acute myocardial ischaemia — STEMI, NSTEMI or unstable angina. STEMI needs immediate reperfusion: “time is muscle”.

Source · Reviewed 2026-08-15 · v1.0— AI-assisted draft — verify against the cited guideline before clinical use.

⚕️ Education only — not medical advice. Verify against the latest official guideline and your local protocol; confirm every drug dose against the cited source before clinical use.

Who gets it

Adults with atherosclerotic risk — age, smoking, diabetes, hypertension, dyslipidaemia and family history. Presentation can be atypical in women, the elderly and people with diabetes.

Red flags — escalate / refer

Ongoing chest pain with ST-elevation (or new LBBB) on ECG = STEMI → immediate reperfusion.
Haemodynamic instability, malignant arrhythmia or cardiac arrest → ACLS / resuscitation.
Ongoing pain despite treatment, or dynamic ECG/troponin changes → urgent cardiology.

Work-up / diagnosis

1Record a 12-lead ECG within 10 minutes of first contact; repeat if evolving.
2Serial high-sensitivity troponin — but in STEMI do NOT wait for troponin to reperfuse.
3Continuous cardiac monitoring; bloods (glucose, lipids, renal, CBC) and a chest X-ray. Classify STEMI vs NSTEMI/unstable angina.

Management — overview

Immediate: aspirin plus a P2Y12 inhibitor (dual antiplatelet) loading, and anticoagulation; oxygen only if hypoxic; nitrate + analgesia for pain.
STEMI: reperfuse — primary PCI preferred (ideally within 120 min); if PCI is not available, give thrombolysis within 12 h of onset (no contraindication), then transfer.
NSTEMI / unstable angina: risk-stratify (e.g. GRACE), give antithrombotics, and use an early invasive strategy by risk.
Secondary prevention for all: high-intensity statin, ACE inhibitor/ARB, beta-blocker, dual antiplatelet therapy, plus lifestyle change and cardiac rehabilitation.

In-depthFull dosing & advanced protocol

Drug dosing

Aspirin

All ACS — give immediately

Adult dose: 150–300 mg loading (chewed), then 75 mg once daily
Route: Oral

WHOWHO Model List of Essential Medicines (electronic EML) (2025 (24th)) ↗

P2Y12 inhibitor (clopidogrel or ticagrelor)

Dual antiplatelet with aspirin

Adult dose: Clopidogrel 300–600 mg load then 75 mg OD (or ticagrelor 180 mg then 90 mg BD)
Route: Oral

WHOWHO Model List of Essential Medicines (electronic EML) (2025 (24th)) ↗

Thrombolytic (e.g. tenecteplase / streptokinase)

STEMI <12 h when primary PCI is unavailable

Adult dose: Per protocol/weight; screen contraindications first
Route: Intravenous

Caution: Absolute contraindications include recent haemorrhagic stroke, active bleeding, recent major surgery/trauma.

ICMRStandard Treatment Workflows (STWs), India — Dept. of Health Research & ICMR (2022+) ↗

High-intensity statin (atorvastatin)

Secondary prevention — start early

Adult dose: 40–80 mg once daily
Route: Oral

WHOWHO Model List of Essential Medicines (electronic EML) (2025 (24th)) ↗

Reperfusion choice & NSTEMI risk

Primary PCI beats thrombolysis if it can be delivered promptly (target first-contact-to-device ≤120 min); otherwise thrombolyse and transfer.
Screen thrombolysis contraindications carefully; give a fibrinolytic only for STEMI, never for NSTEMI.
NSTEMI/UA: GRACE score guides timing of invasive angiography; continue antithrombotics.

ICMRStandard Treatment Workflows (STWs), India — Dept. of Health Research & ICMR (2022+) ↗

Complications & secondary prevention

Watch for arrhythmia, heart failure and mechanical complications after MI.
Discharge bundle: DAPT duration per risk, statin, ACEi/ARB, beta-blocker, risk-factor control and cardiac rehab.

References

Guidelines change. If something here is out of date, tell us — we keep these current.

🚩 Report outdated / suggest update

More protocols

Acute Heart FailureRapid onset or worsening of heart-failure symptoms — breathlessness, orthopnoea and oedema, often with pulmonary congestion. Relieve congestion and find the trigger.Hypertensive EmergencySevere blood-pressure elevation (usually >180/120 mmHg) WITH acute target-organ damage (brain, heart, kidney, retina). Needs controlled IV lowering — distinct from asymptomatic severe hypertension ('urgency').Atrial Fibrillation (AF)The commonest sustained arrhythmia — an irregularly irregular pulse with no P waves on ECG. The two key harms are stroke (thromboembolism) and heart failure; management is rate/rhythm control plus stroke-risk-based anticoagulation.

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👤 Who gets it

🚩 Red flags — escalate / refer

🔎 Work-up / diagnosis

🧭 Management — overview

💊 Drug dosing

Aspirin

P2Y12 inhibitor (clopidogrel or ticagrelor)

Thrombolytic (e.g. tenecteplase / streptokinase)

High-intensity statin (atorvastatin)

📈 Reperfusion choice & NSTEMI risk

📈 Complications & secondary prevention

📚 References

More protocols

👤 Who gets it

🚩 Red flags — escalate / refer

🔎 Work-up / diagnosis

🧭 Management — overview

💊 Drug dosing

Aspirin

P2Y12 inhibitor (clopidogrel or ticagrelor)

Thrombolytic (e.g. tenecteplase / streptokinase)

High-intensity statin (atorvastatin)

📈 Reperfusion choice & NSTEMI risk

📈 Complications & secondary prevention

📚 References

More protocols

Who gets it

Red flags — escalate / refer

Work-up / diagnosis

Management — overview

Drug dosing

Reperfusion choice & NSTEMI risk

Complications & secondary prevention

References

Who gets it

Red flags — escalate / refer

Work-up / diagnosis

Management — overview

Drug dosing

Reperfusion choice & NSTEMI risk

Complications & secondary prevention

References