Understanding STEMI: Complete ECG Recognition Guide

Introduction to STEMI

ST-Elevation Myocardial Infarction (STEMI) represents a critical cardiac emergency requiring immediate recognition and treatment. This comprehensive guide will help you master STEMI identification on ECG.

Key Diagnostic Criteria

ST Segment Elevation Measurements

• Men under 40: ≥2.5 mm in leads V2-V3
• Men over 40: ≥2 mm in leads V2-V3
• Women: ≥1.5 mm in leads V2-V3
• Other leads: ≥1 mm in two contiguous leads

Lead Patterns and Coronary Territories

Anterior STEMI (LAD Occlusion)

• Leads: V1-V4
• Associated: Reciprocal changes in inferior leads

Inferior STEMI (RCA or LCx)

• Leads: II, III, aVF
• Check: Right ventricular involvement (V4R)

Lateral STEMI (LCx)

• Leads: I, aVL, V5-V6

Clinical Pearls

1. Always check for reciprocal changes - Increases specificity
2. Wellens syndrome - Warning sign of critical LAD stenosis
3. STEMI mimics - Pericarditis, early repolarization, LVH

Management Priorities

• Time is muscle - Door-to-balloon < 90 minutes
• Reperfusion therapy - PCI vs thrombolysis
• Antiplatelet therapy - Aspirin + P2Y12 inhibitor

Conclusion

Rapid STEMI recognition on ECG is a life-saving skill. Practice these patterns regularly and always correlate with clinical presentation.

Related Resources

• ECG Basics Tutorial
• Myocardial Infarction Videos
• Practice ECG Cases