clinical_update

2025 ACC/AHA Guidelines Redefine ECG Criteria in Acute Coronary Syndromes

New J-point thresholds, reperfusion strategies, and imaging roles in emergency cardiac care

By Dr. Raj K | Published on June 21, 2025

2025 ACC/AHA Guidelines Redefine ECG Criteria in Acute Coronary Syndromes

Introduction

The American Heart Association (AHA), in collaboration with the ACC, ACEP, NAEMSP, and SCAI, has released its 2025 guideline for managing patients with suspected acute coronary syndromes (ACS). These new recommendations update ECG interpretation, the role of imaging, and emergency triage strategies—offering major implications for physicians, EMS, and critical care teams.

Key Updates in ECG Interpretation

The guideline revises several core elements of early ECG analysis in suspected myocardial infarction:

ST-Elevation Thresholds:

  • Men <40: ≥2.5 mm in V2–V3
  • Men ≥40: ≥2.0 mm in V2–V3
  • Women: ≥1.5 mm in V2–V3
  • ≥1 mm in all other contiguous leads

J-Point Assessment:

convex vs concave ST segments and horizontal and downsloping ST elevations
  • Greater emphasis on horizontal/downsloping ST elevation over convexity
  • Avoid overcalling benign early repolarization

Bundle Branch Blocks:

New LBBB Criteria for MI - SGARBOSSA criteria
  • New or presumed new LBBB remains concerning, but Sgarbossa criteria refinements improve accuracy

Posterior MI:

  • V7–V9 leads encouraged when ST depression seen in V1–V3

Diagnostic Flow & Imaging Role

  • Immediate ECG within 10 minutes remains a class I recommendation
  • Point-of-care cardiac ultrasound (POCUS) now class IIa for bedside triage in undifferentiated chest pain
  • Intracoronary imaging (IVUS/OCT) has a stronger recommendation for equivocal angiograms

Risk Stratification & Timing

  • Risk score-based approach (e.g., HEART, TIMI) emphasized before routine non-invasive testing
  • New timelines:
  • <90 mins: PCI for STEMI
  • <120 mins: Acceptable for STEMI in non-PCI centers with fast transfer
  • <24 hrs: Early invasive strategy for selected NSTEMI/high-risk UA

Implications for Emergency and Prehospital Teams

These updates call for:

  • Faster ECG acquisition and interpretation protocols
  • Real-time feedback for ST changes (esp. AI-supported ECG tools)
  • Inclusion of serial ECGs in grey-zone chest pain

Conclusion

The 2025 ACC/AHA guideline refines how clinicians should interpret the ECG in acute chest pain. It prioritizes precision, contextualization, and earlier use of adjunctive tools—laying the groundwork for faster, more accurate decisions.

Reference

2025 ACC/AHA/ACEP/NAEMSP/SCAI Guideline for the Evaluation and Management of Patients With Suspected Acute Coronary Syndrome. Circulation 2025. Read full guideline

Research Reference:

2025 ACC/AHA/ACEP/NAEMSP/SCAI Guideline for the Evaluation and Management of Patients With Suspected Acute Coronary Syndrome. Circulation 2025.

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