ECG Exam Template

The following headings and prompts can be used as template for ECG-based exam questions, such as the FACEM Part II VAQs.

ECG type and recording

  • 12 lead vs rhythm strip, rate (normal 25 mm/s)
  • Calibration (5mm wide, 10mm high = 1mV)
  • Unusual leads – right, posterior, lead grouping format

Rate

  • normal 60 – 100/min; tachy/brady
  • -cardia (SA node) vs –arrhythmia (not SA node)
  • method: 300/RR interval (large squares) or number of QRS complexes x 6 (if 25mm/s)

Rhythm

  • Pattern – regular/ regularly irregular/ irregularly irregular
  • Seven step approach to rhythm analysis

Axis

  • Normal QRS axis -30 to 90/ LAD/ RAD/ NW axis
  • Rotation (clockwise/ anticlockwise)
  • Methods: 1. Quick look test (e.g. I And AvF) 2. Isoelectric line

P wave

  • Present? (esp check II and V1)
  • Amplitude + duration: normal <3mm high and wide (LAE/RAE/both)
  • Contour: normal — inverted aVR, biphasic V1, upright I,II, aVF, V2-V6

PR interval + PR segment

  • Duration 0.12-0.2s normal/ short/ long/ varying
  • heart blocks: 1st, 2nd type I and II, 3rd degree
  • Depression

Q wave

  • Normal: <25%R in I, aVL, AVF, V456
  • Pathological: V23 > 0.02s, other >0.03s + >1mm deep

R wave

  • Transition: normal V34, early: R>S in V1/2
  • Poor R Wave Progression: R <3mm V3

QRS complex

  • Duration: 60-110msec normal/ wide; R wave peak time
  • Amplitude: normal/ large voltage/ low voltage/ alternans
  • Morphology: notched/ RBBB/ LBBB

ST Segment

  • Displacement: elevation/ depression (J point vs TP interval)
  • Contour: horizontal /upsloping / downsloping

T wave

  • Amplitude: normal <2/3 R/ peaked/ inversion/ alternans

QT Interval

  • Duration: normal 390-450 or 460msec / long/ short/ QT dispersion
  • Method, 3+ QRS in 3+ leads, QTc formulae, caveats

U wave

  • normal 10%T or <1.5mm/ prominent/ inversion/ alternans

Additional waves

Chamber hypertrophy

Lethal – do not miss!

Other tricks and traps

Synthesis

  • Leave space to put this at the start of the answer
  • Unifying diagnosis, DDx, life threats
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