ECG #22

A 59-year-old man presents to the emergency department with anaphylaxis from a bee sting. Describe and interpret his initial 12-lead electrocardiogram:

ECG 1

Solution to follow …

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ECG #21

A 67-year-old man presents to the Emergency Department with the onset of central dull chest pain, radiating down his right arm, whilst eating his lunch (onset ∼ 45 minutes ago).

Describe and interpret his initial 12-lead electrocardiogram:

ECG 1

Solution to ECG #20

Initial ECG

ECG 1

For the initial ECG (above) the precordial electrodes were misplaced over the right side of the chest whilst maintaining the correct placement of the limb electrodes. This has resulted in poor R-wave progression in the precordial leads with decreasing QRS amplitudes and T-wave inversion. The limb leads remain normal/unchanged.

Repeat ECG (with corrected electrode placement):

ECG 2

This is similar to the characteristic pattern seen in dextrocardia:

  • Right axis deviation
  • Inversion of aVR (global positivity)
  • Inversion of lead I (global negativity)
  • Absent R-wave progression in the precordial leads with dominant S waves throughout

Of note, reversal of the left and right upper limb electrodes may produce a similar picture to dextrocardia in the limb leads, but with normal appearances in the precordial leads. See LITFL for an excellent review on on the topic of limb lead reversals.

 

Solution to ECG #18

1st ECG – ? electrode misplacement

ECG #1

2nd ECG (below) is from the same patient repeated 30 minutes later with correct electrode placement. This confirmed left upper and lower limb electrode reversal:

ECG #2

  • Lead III becomes inverted
  • Leads I and II switch places
  • Leads aVL and aVF switch places
  • Lead aVR remains unchanged