ECG within 10 min. STEMI: primary PCI if achievable within 120 min of diagnosis, otherwise fibrinolysis within 10 min and transfer. Load antiplatelets, anticoagulate, and risk-stratify NSTE-ACS for timing of angiography.
At the bedside
Timed steps- 1
12-lead ECG
0-10 minSTEMI: new ST elevation ≥ 1 mm in 2 contiguous leads (V2-V3 ≥ 2.5 mm men < 40 y, ≥ 2 mm men ≥ 40 y, ≥ 1.5 mm women), LBBB/paced rhythm with ischaemic symptoms, posterior MI (ST depression V1-V3). Repeat every 15-30 min if non-diagnostic.
- 2
Initial care
0-10 minMonitor, IV access, O2 only if SpO2 < 90%, aspirin 150-300 mg, cautious IV opioid, GTN if no hypotension or RV infarct. High-sensitivity troponin 0/1 h or 0/2 h.
- 3
Reperfusion decision
STEMISymptoms < 12 h: primary PCI if diagnosis-to-wire ≤ 120 min; otherwise fibrinolysis within 10 min of diagnosis.
- 4
Give
FibrinolysisTenecteplase by weight (half dose if ≥ 75 y) + clopidogrel 300 mg (75 mg if > 75 y) + enoxaparin or UFH.
- 5
After lysis
60-90 min< 50% ST resolution, ongoing pain or instability: rescue PCI. Otherwise angiography 2-24 h after lysis.
- 6
Risk-stratify
NSTE-ACSVery high risk (shock, refractory pain, life-threatening arrhythmia, mechanical complication, acute HF, recurrent dynamic ST changes): angiography < 2 h. High risk (confirmed NSTEMI, dynamic ST/T changes, GRACE > 140): < 24 h.
- 7
Antithrombotics
AllAspirin + P2Y12 inhibitor (ticagrelor or prasugrel at PCI; clopidogrel with lysis or oral anticoagulant) + parenteral anticoagulant.
- 8
Secondary prevention
Before dischargeHigh-intensity statin, ACE-i/ARB, beta-blocker if LVEF ≤ 40%, MRA/SGLT2i if HFrEF, cardiac rehabilitation.
Loading
Aspirin
- Dose
- 150-300 mg, then 75-100 mg daily
P2Y12 (PCI pathway)
Ticagrelor
- Dose
- 180 mg, then 90 mg twice daily
P2Y12 with fibrinolysis
Clopidogrel
- Dose
- 300 mg (75 mg if > 75 y), then 75 mg daily
STEMI fibrinolysis
Tenecteplase
- Dose
- 30-50 mg by weight; half dose if ≥ 75 y
- Worked example
- 72 kg, 60 y: 40 mg = 8 mL of 5 mg/mL
Anticoagulant with fibrinolysis
Unfractionated heparin (UFH)
- Dose
- 60 U/kg bolus (max 4000 U), then 12 U/kg/h (max 1000 U/h)
- Preparation
- 25 000 U in 50 mL = 500 U/mL
- Target
- aPTT 50-70 s
- Worked example
- 70 kg: 4000 U bolus, then 840 U/h = 1.7 mL/h
Anticoagulant with fibrinolysis (< 75 y)
Enoxaparin
- Dose
- 30 mg IV, then 1 mg/kg SC every 12 h (first 2 doses max 100 mg)
Tenecteplase weight-based dose
| Weight (kg) | Dose (mg) | Volume of 5 mg/mL (mL) |
|---|---|---|
| < 60 | 30 | 6 |
| 60-69 | 35 | 7 |
| 70-79 | 40 | 8 |
| 80-89 | 45 | 9 |
| ≥ 90 | 50 | 10 |
Half dose if age ≥ 75 years (ESC 2023).
References
- 1
- 2
STEMI reperfusion
Step 1 of ~3
Decision: Symptoms < 12 h or ongoing ischaemia/instability?
Based on Byrne RA, Rossello X, Coughlan JJ, et al. Educational use; follow local protocol.
Evidence
- ESC ACS 2023: primary PCI if feasible within 120 min; otherwise fibrinolysis within 10 min; half-dose tenecteplase ≥ 75 y; pharmaco-invasive angiography 2-24 h; NSTE-ACS timing by risk.
- ACC/AHA 2025: similar framework for reperfusion, P2Y12 choice and early invasive strategy in high-risk NSTE-ACS.
Controversies
- Routine beta-blockers after MI with preserved EF (REDUCE-AMI: no benefit).
🇮🇳 India notes
- Many Indian STEMI patients are young, diabetic and present late; the pharmaco-invasive (lysis then transfer) model is realistic in most districts.
- Streptokinase remains in use for cost reasons; it is less effective and causes hypotension.
References
- 1
- 2
Test yourself
Module quiz · score 70% to complete the module
Educational reference for trained clinicians. Check doses against your hospital protocol and the patient in front of you.