Imagine you are an emergency physician working in a medium-sized community hospital.
It’s a busy day in the emergency department. You are the only physician on duty.
One of the nurses has called in sick, there is no tech, and the weakest unit secretary is on duty.
All the rooms are full, the waiting room is packed, the ambulance bay is jammed, and there are overflow patients waiting to be admitted.
There is a policy in the emergency department that the emergency physician shall review the 12-lead ECG of chest pain patients within 10 minutes of the patient’s arrival.
You are suturing a large laceration in a patient’s leg when a nurse walks in, holds up an ECG and says, “We have a walk-in chest pain patient in bed 4.”
It’s going to take you another 20 minutes to suture up the patient’s laceration.
What are your orders?
This patient was experiencing an acute inferior STEMI and reperfusion was delayed.
Those of you who predicted that the white and red electrodes were switched were exactly right. TheÂ frontal plane axisÂ is in the right superior quadrant (no manâ€™s land) which is unusual and should tip you off that thereâ€™s an error with lead placement.
Whatâ€™s really unfortunate about this case is that physical inspection of the leads would have shown them to be placed properly. Thatâ€™s because the leads themselves werenâ€™t misplaced.
The leads were â€œplugged inâ€ to the machine backwards.
The result was the transposition of the white and red electrodes.
In reality, you can still see the STEMI if you know what to look for. One of the â€œtricksâ€ I teach students to help them identify acute posterior STEMI is to ignore the limb leads for acute inferior STEMIs and look only at the right precordial leads (V1-V3).
This helps â€œtrain the eyeâ€ to see subtle signs of acute posterior STEMI and this case demonstrates why having a â€œtrained eyeâ€ could be potentially life-saving.
In this case, there is a slight downsloping of the ST-segment in lead V2.
Throw in the â€œclassicâ€ appearance of lead aVL (reciprocal change) and this 12-lead ECG is highly suspicious for acute inferio-posterior STEMI.
So, when trouble-shooting a 12-lead ECG remember to check both the leads and the connections!