ECG of the Week: ECG of the Week - 24th September 2018

Wednesday, 26 September 2018

ECG of the Week - 24th September 2018 - Interpretation

This ECG is from a 15 year old male who presented with episodes of symmetrical hands turning cold and blue (symmetrically) which lasted for a few hours before improving. No prior past medical history, no regular medications. Very fit and active.

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Rate:

60 bpm

Rhythm:

Regular
Atrial activity present but inverted P wave leads V2 & V5

Axis:

Extreme

Intervals:

PR - Normal
QRS - Normal

Additional:

T wave inversion leads II, III, aVF, V1-2, V5
Abnormal R wave transition in precordial leads

Negative QRS leads V1-2
Positive QRS leads V3-4
Negative QRS leads V5-6

Complete lead inversion V2 & V5 (Negative P, negative QRS, negative T)

Interpretation:

The combination of abnormal R wave transition, complete lead inversion leads V2 & V5 plus extreme axis should always alert us to the possibility of lead reversal.
This is clearly not a 'simple' reversal i.e. only 2 leads misplaced but far more complex. The odds of every lead being attached to a patient incorrectly is very small but the connection between the leads and the machine is much easier to misconnect especially when old and worn. This what happened in this case with the connecting terminal for all the leads was placed upside down into the ECG machine with resultant lead swaps as below.

Expected lead Actual lead
RL RL
RA V6
V1 V1
V2 RA
V3 V5
V4 V4
V5 LA
V6 V2
LA V3

LL LL

Once corrected the patients subsequent ECG was entirely normal !

References / Further Reading

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