Thursday, December 16, 2010

ECG Interpretation Review - #2 ("Smiley" ST, ST Elevation, Early Repolarization, LVH by Voltage)

QUESTION: Interpret the 12-lead ECG below.

  • What IF this patient was a healthy, asymptomatic young adult?
  • A young adult with recent URI and pleuritic chest pain?
  • An older adult with risk factors and severe, new-onset chest pain?
(ECG reproduced from ECG-2014-ePub)
- Note - Enlarge by clicking on Figures -
INTERPRETATION:  The rhythm is sinus at ~60/minute.  The PR, QRS, and QT intervals are normal.  We estimate the axis at +60 degrees.
  • Chamber Enlargement - The sum of the S wave in lead V2 (=3 large boxes = 15 mm) plus the R wave in V5 or V6 (~5 large boxes = 25 mm) clearly exceeds 35.  This satisfies voltage criteria for LVH (provided that the patient is older than 35).
  • Q-R-S-T Changes - A Q wave and T wave inversion is seen in lead III (which as isolated findings may be normal).  There are small septal q waves in leads V5,V6.  Transition is normal (occurring between leads V3 to V4).  The most remarkable finding is ST segment elevation in multiple leads.  ST segments manifest an upward concavity (ie, "smiley" configuration), with J-point notching (arrow in V5).

CLINICAL IMPRESSION: Our interpretation of this ECG depends on the clinical scenario. IF the patient in question was an otherwise healthy, asymptomatic young adult - then the upward concavity ("smiley" shape) ST segment elevation would be consistent with early repolarization.  IF instead the patient was older with chest pain - then despite the "smiley" shape, acute MI would have to be ruled out.  Finally - IF the chest pain was pleuritic (especially if associated with a recent URI in a young adult) - then this same ECG could reflect acute pericarditis.  Note how in each case Descriptive Analysis does not change (with our interpretation being determined in conjunction with careful consideration of the clinical setting).
      - See also ECG Blog Review #12 -
- Click on this link for more info on Early Repolarization (Look at the part beginning with Section 09.14).


  1. ST elevation in lead V3 is quite straight... In a young patient with pleuritic chest pain with recent URI, i would still consider ACS 1st in the differential.. Any thoughts? Thank you..

    1. @ Anonymous — "Ya gotta be there". If the history was not at all suggestive of ACS in an otherwise healthy young adult with pleuritic chest pain — then the odds are great that this is not ACS. If on the other hand the history was indeed suggestive of new-onset chest pain — then despite J-point notching + upward concavity ST elevation in most leads, one would have to go further to rule out ACS. Serial tracings and a stat Echo during symptoms looking for wall motion abnormality would be helpful. It IS of course possible to have ACS superimposed on a baseline tracing of early repolarization — and there are times when distinction between benign vs ACS is not readily apparent (if possible at all) from a single tracing.