STE-ACS? Abnormal J-point elevations in 2 or more anatomically contiguous leads? - in males: ≥ 0.2 mV (2 mm) (< 40 y? 0.25 mV (2.5 mm)) in V2-3 and ≥ 0.1 mV (1 mm) in all other leads - in females: ≥ 0.15 mV (15 mm) in V2-3 and ≥ 0.1 mV (1 mm) in all other leads NSTE-ACS? Abnormal J-point depressions? - ≥ -0.05 mV (-0.5 mm) in leads V2 and V3 and ≥ -0.1 mV (-1 mm) in all other leads - Transient ST-elevation - New T-wave inversion If the initial ECG is not diagnostic but patient remains symptomatic and high clinical suspicion for ACS? - Serial ECGs (eg 15- to 30-minute intervals during the first hour)? Notes: - A normal ECG does not exclude ACS and occurs in 1% to 6% of such patients - A normal ECG may also be associated with left circumflex or right coronary artery occlusions, which can be electrically silent (in which case posterior electrocardiographic leads [V7 to V9] may be helpful) - Right-sided leads (V3R to V4R) are typically performed in the case of inferior STEMI to detect evidence of right ventricular infarction - LVH, BBB with repolarization abnormalities and ventricular pacing may mask signs of ischemia/injury Reference(s): AHA/ACC (2014): Guideline for the Management of Patients With Non–ST-Elevation Acute Coronary Syndromes. A Report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines AHA/ACCF/HRS (2009): Recommendations for the Standardization and Interpretation of the Electrocardiogram. Part VI: Acute Ischemia/Infarction: A Scientific Statement from the American Heart Association Electrocardiography and Arrhythmias Committee, Council on Clinical Cardiology; the American College of Cardiology Foundation; and the Heart Rhythm Society