Does ST-Elevation Myocardial Infarction (STEMI) require ST segment elevation in 2 contiguous leads?

From the Guidelines

STEMI diagnosis requires ST segment elevation in at least 2 contiguous leads, as defined by the European Society of Cardiology/ACCF/AHA/World Heart Federation Task Force for the Universal Definition of Myocardial Infarction, with specific criteria including new ST elevation at the J point in at least 2 contiguous leads of ≥2 mm (0.2 mV) in men or ≥1.5 mm (0.15 mV) in women in leads V2–V3 and/or of ≥1 mm (0.1 mV) in other contiguous chest leads or the limb leads 1.

Key Diagnostic Criteria

• New ST elevation at the J point in at least 2 contiguous leads
• Specific criteria for men (≥2 mm or 0.2 mV) and women (≥1.5 mm or 0.15 mV) in leads V2–V3
• ≥1 mm (0.1 mV) in other contiguous chest leads or the limb leads
• Contiguous leads represent adjacent areas of the heart, indicating a significant area of myocardial injury

Importance of Contiguous Leads

• Elevation in multiple contiguous leads distinguishes true STEMIs from other conditions causing ST elevation in a single lead
• Prompt recognition of these ECG changes is critical for immediate reperfusion therapy
• Examples of contiguous leads include II, III, and aVF for the inferior wall, and V1-V4 for the anterior wall

Clinical Context and Next Steps

• Baseline ECG abnormalities, such as LBBB, paced rhythm, or LV hypertrophy, may obscure interpretation
• Transthoracic echocardiography or immediate referral for invasive angiography may be necessary to guide therapy in difficult cases
• Cardiac troponin is the preferred biomarker for diagnosis of MI, supporting the diagnosis of STEMI in the appropriate clinical context 1

From the Research

STEMI Diagnosis

• STEMI requires ST segment elevation in ≥2 contiguous electrocardiographic leads, as stated in current guidelines 2.
• The diagnosis of STEMI is crucial for immediate reperfusion therapy, and differentiating it from nonischemic ST-elevation is essential 2, 3.

Contiguous Leads Requirement

• The requirement for ST segment elevation in 2 contiguous leads is a key criterion for diagnosing STEMI 2.
• This criterion helps differentiate STEMI from other conditions that may cause ST segment elevation, such as pericarditis or early repolarization 4, 5.

Importance of Accurate Diagnosis

• Accurate diagnosis of STEMI is critical for timely and effective treatment, including primary percutaneous coronary intervention (PCI) or fibrinolysis therapy 3, 6.
• Incorrect diagnosis or delayed treatment can lead to increased morbidity and mortality 3, 6.