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"A Cold Case"

46-year-old male patient with a high BMI, known paraplegic secondary to old spinal cord injury, was found on the floor in the morning by his carer.

It was not clear how much he spent on the floor but probably it was for a full night.

He was very confused but vitally stable, & his blood tests showed Acute Kidney Injury (AKI), likely secondary to rhabdomyolysis because of the long lie on the floor.


This was his ECG,



Can you guess what the reason was for the abnormalities in this ECG?


Let's start analyzing the ECG,


The first abnormality in this ECG is the QTc, which is 523 ms, i.e. seriously prolonged.


QTc can be prolonged for the following reasons: (This is a must-know D.D)


1) Congenital:

  • Romano-Ward syndrome.

2) Metabolic: (all Hypo)

  • Hypo K.

  • Hypo Ca.

  • Hypo Mg.

  • Hypo Thermia.

  • Hypo Thyroidism.

3) Drugs:

  • Na channel blockers, e.g.TCA, Amidarone.

  • Antipsychotics, Antidepressants.

  • Antihistamine.

  • Ondansetron.

  • Macrolides Antibiotics.

  • Methadone.

4) Others:

  • Increased Intracranial Pressure (ICP).

  • Acute Coronary Syndrome (ACS).


"Here is a very common dangerous scenario that can happen in any Emergency Department"


A young patient who is known to have mental health problems presents with a chest infection & nausea. You would give antibiotics (likely Amoxicillin + Clarithromycin as per most guidelines), and you would also give Ondansetron for nausea (the most commonly used anti-emetic in most Emergency Departments).


This patient is almost guaranteed to develop ventricular tachycardia (VT) with this treatment considering that most mental health patients will be already on antidepressants/antipsychotics, & you have just added on top Clarithromycin & Ondansetron. With this number of drugs that prolong the QTc, the chances of having a bad outcome are really high, especially if you add on top that we don't routinely get an ECG for patients with a chest infection, so you won't know what the baseline QTc is!


Back to the ECG,


The 2nd abnormality here is an interesting wave at the end of the complexes.


You will notice that this wave is positive with positive complexes like this example



And negative with negative complexes, like this example



This is called "The Osborn waves (J-waves)”


  • These are positive deflections at the J point in most leads, and negative in aVR & V1.

  • They are usually most prominent from V2-6.

  • It was thought initially to be pathognomonic for hypothermia, but it is also seen in hyper Ca & increased ICP.


So this will leave us with only 2 out of the D.D. of prolonged QTc:


1) Hypothermia.

2) Raised ICP.


This will take us to the 3rd abnormality in the above ECG, the movement artifacts in leads I & III (shivering).


There is only one answer when you combine the long QTc + the J-waves + shivering artifacts.


The Answer:


This was a case of HYPOTHERMIA, this patient was found to have a temperature of 29 degrees due to the long lie.


Obviously, I am not advocating at all in diagnosing hypothermia using the ECG, as there are easier methods! But I thought it was an interesting ECG to see, plus it is a very common question in post-graduate exams for some reason!


ECG changes with Hypothermia:


1) Prolonged PR, QRS & QT interval.

2) Brady-arrhythmias (sinus bradycardia, slow AF).

3) Osborn wave (J-waves) - Can mimic a STEMI!

4) Shivering artifacts.

5) Ventricular ectopics.


Other Examples:


Here is another great example of hypothermia when it looks like STEMI, with all the above findings.


Courtesy to Tom Cromwell, UK.


Here is a 3rd example of hypothermia ECG changes, the temperature was 28 degrees.



For references & further readings about Hypothermia:



I hope you found this useful.

See you soon with the next blog.

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Guest
Mar 03
Rated 5 out of 5 stars.

Excellent!

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Guest
Mar 02
Rated 5 out of 5 stars.

Thank you, great explanation.

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Thee
Thee
Mar 02
Rated 5 out of 5 stars.

👌👌

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