DSAE STEMI Review: Utilization of the Acronym HEART

The HEART acronym provides the following steps to help insure that all aspects of the 12-lead are carefully examined and that no stone is left unturned.

H = Hypertrophy – apply the *criteria of LVH (please note some authors utilize slightly different criteria; for clarity, we will use the following below.)

As follows:  LVH present if…. S + R > 35 mm where…

S = Tallest S-wave of V1, V2, V3

R = Tallest R-wave of V4, V5, V6


R-wave > 12 mm Lead avL

*applicable only if age > 35 years

PEARL:  The criteria above does not apply in the presence of LBBB, LAFB or WPW.

E = Extent of Intervals – measure the intervals PR, |QRS|, QT

NORMAL Ranges as follows:

  • PR = 0.12 – 0.20 sec
  • |QRS| ≤ 0.10 sec
  • QT < 1/2 of RR (if not tachy or brady)

A = Axis – Calculate the frontal electrical axis

The axis is normal if———Leads I and avF are positive

Consider LAFB if axis ≤ – 45 degrees (more negative than – 45°)

Left Axis if:  Lead I positive and Lead avF negative

R = QRS- ST Analysis – look for significant Q-waves, transition zone, ST-elevation, ST-depression,R-wave progression

Normal if:

  • No significant Q-waves
  • No ST segment changes
  • Transition zone occurs between (V2, V3, V4) inclusive
  • R-wave progression normal

T = T-wave – look at all T-waves in search of ischemia/infarction

All T-waves are upright(except maybe in Leads V1, avL, avF or III)

If otherwise inverted, consider ischemia

Consider Hyperacute if: tall, peaked broad-based, symmetrical

Now click “MARK COMPLETE” or “NEXT”.