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Early Repolarization

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Early Repolarization, Benign Early Repolarization, J Point Elevation, J-Point Elevation

  • See Also
  1. ST Segment
  2. ST Elevation
  3. Electrocardiogram in Myocardial Infarction
  4. J Wave Syndrome
  5. Electrocardiogram
  • Epidemiology
  1. Prevalence: 5% of general population
  2. Most common in healthy young patients under age 50 years old
  • Risk Factors
  1. Young men
  2. African american
  3. Athletes
  4. Bradycardia
  • Signs
  1. Characteristics
    1. ST Segment Elevation with a concave upwards appearance (Smiley appearance) in V2-V5
      1. ST Elevation < 2 mm in precordial leads (may be up to 5 mm in atypical cases)
      2. May be accompanied by concave upward inferior lead ST Elevation
        1. ST Elevation <0.5 mm in limb leads
        2. Inferior ST Elevation should not be isolated (precordial leads should also be involved)
        3. ST Elevation should be greater in lead II than lead III
    2. Contrast with acute coronary events
      1. Convex upwards appearance (Tombstone, Frown appearance) of an acute coronary event
      2. No reciprocal ST depression (V1 and aVR are the exceptions)
  2. Distribution
    1. Widespread across precordial leads (especially V2 to V5) with or without inferior lead involvement
  3. Asociated findings
    1. J Wave (deep J Waves are associated with worse prognosis)
      1. Notch or slurring at the end of the QRS Complex
    2. T Waves
      1. Prominent T Waves that are concordant with the QRS
      2. ST Segment Elevation is <25% the height of the T Wave (leads V4-6, lead I)
  • Precautions
  • Red Flags NOT consistent with Early Repolarization
  1. Convex upwards ST Elevation (Tombstone)
    1. ST Elevation Myocardial Infarction until proven otherwise
  2. Reciprocal ST depression
    1. Reciprocal ST depression (aside from aVR or V1) is a ST Elevation Myocardial Infarction until proven otherwise
  3. ST Elevation in the Inferior Leads
    1. Suspect STEMI if ST Elevation is greater in lead III than lead II
    2. Suspect STEMI if isolated inferior lead ST Elevation (but no ST Elevation in the precordial leads)
  4. ST Elevation >5 mm
    1. Early Repolarization is usually <5 mm
  • Interpretation
  • Studies with mixed results on prognosis
  1. Early Repolarization has been long considered a benign finding until 2008
  2. Brugada Syndrome and Early Repolarization Syndrome are both J Wave Syndromes
  3. Studies in 2008 suggested possible connection between Early Repolarization and sudden Cardiac Arrest
    1. If risk is increased it appears to manifest in the longterm (5-30 years of follow-up)
    2. Haissaguerre (2008) N Engl J Med 358(19): 2016-23 [PubMed]
  4. Large study in 2011 showed no increased risk of Sudden Cardiac Death
    1. However, study sample was skewed to older, white patients
    2. More typical cohort of concern would be younger african american patients described above under risk factors
    3. Uberoi (2011) Circulation 124(20): 2208-14 [PubMed]
  • Prognosis
  1. If Early Repolarization increases Sudden Cardiac Death, the risk is a longterm risk (over as much as 30 years)
    1. Manage emergency department patients based on their presenting symptoms (e.g. Syncope)
    2. Asymptomatic Early Repolarization incidently found on EKG can be addressed on a routine basis
      1. Aggressive measures (e.g. AICD) are not indicated in asymptomatic patients
  2. Early Repolarization associated risk of idiopathic Ventricular Fibrillation or early cardiac death
    1. Associated with 4-10 fold increased risk of Sudden Cardiac Death (10 year risk)
    2. Incidence overall: 3.4 per 100,000
    3. Incidence if J Wave present (esp. >2mm in inferior leads): 11 per 100,000
    4. Benito (2010) J Am Coll Cardiol 56(15): 1177-86 [PubMed]
  • Resources
  1. Early Repolarization vs STEMI (Amal Mattu, UMEM)
    1. https://em.umaryland.edu/educational_pearls/1231/
  • References
  1. Krishnan (2018) Cardiac Arrhythmias Conference, UMN, Minneapolis
  2. Mattu and Herbert in Herbert (2012) EM:RAP 12(3): 4
  3. Grauer (2001) 12 Lead EKGs, 2nd ed, KG/EKG Press, Gainesville, Florida