Young man with Gunshot wound to right chest with hemorrhagic shock, but bullet path not near heart. A case of irregular accelerated idioventricular rhythm (AIVR)

A young man presented with a gunshot wound to the right chest, with hemo-pneumothorax and hemorrhagic shock.

He got a chest tube and intubation and massive transfusion and stabilized.

CT of chest showed the bullet path through his right lung but nowhere near his heart.

But he did get an EKG:

What is this?  There were times when it would be usurped by sinus tachycardia, then return to this rhythm.

There is a wide complex.  It is irregular.  It is not fast (cannot be VT).  There is no atrial activity to suggest atrial fibrillation.  

There are what could be interpreted as delta waves if, and only if, there were P-waves or other atrial activity preceding the QRS (pre-excitation can only happen when there is an impulse originating in the atria).  Therefore, these are NOT delta waves and this is NOT pre-excitation!

I could only conclude that this was an irregular accelerated idioventricular rhythm.  I concluded that it is safe and did not require treatment and to leave it alone unless it became too slow, at which point atropine would be indicated to increase the sinus rate to let that sinus rate take over.

AIVR should never be treated with anti-dyrrhythmics!!  It is a stable rhythm.  Atropine is ok to improve the sinus rate if the heart rate is too slow.

All troponins were negative.

Formal echo was normal.

Here are 4 more ECGs recorded over the ensuing hours:

Another irregular AIVR

Back to sinus rhythm

This is a normal regular AIVR

Another normal regular AIVR

On that first ECG, I was not entirely certain, since I have never seen nor heard of irregular AIVR, nor can I find a report of it in the literature.  But I have seen AIVR in young people with trauma (see case below)

So I sent it to Ken Grauer and here are his comments:

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For clarity — I've reproduced in Figure-1 the ECG that Dr. Smith sent me (Ken Grauer, MD — 3/7/2024).

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Figure-1: The ECG sent to Ken Grauer (showing some semblance of "group" beating).

Hi Steve. This looks VERY bizarre … I don’t see P waves. With a GSW to the chest and what certainly looks like abnormal ST changes (including marked ST elevation in I,aVL) — there is presumably significant cardiac injury that could cause weird rhythms.

• The QRS is VERY wide — and the very wide Q in lead I (showing marked axis deviation) certainly suggest a ventricular etiology. Lots of leads almost look like delta waves — but I hate to diagnose delta waves when there are no P waves.
• This does NOT seem irregularly irregular enough for AFib … Instead — there is almost “group beating” with “Wenckebach periodicity”. That is, R-R intervals are decreasing within groups — and the pauses (ie, between beats #3-4; 8-9; and 13-14) are less than twice the shortest R-R interval. 
• My guess is this is an irregular Accelerated Ventricular Rhythm (which can occur when there is “triggered” activity) — perhaps with Wenckebach conduction out of the ectopic ventricular focus.
• That said — it is not impossible for AFib + complete AV block to manifest Wenckebach conduction out of the AV nodal escape (We used to see this when Dig toxicity was common … ) — but my guess in this case is “triggered” activity irregular AVR … 
• In any event — I don’t think I’d try and treat this rhythm given the reasonable ventricular rate (and I’d hope the rhythm improves as the GSW to chest is treated … ).

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I had a previous case of an adolescent with trauma and chest pain who also had AIVR:

An adolescent with trauma, chest pain, and a wide complex rhythm

From this blog post: "AIVR is NOT common in otherwise healthy children. I’ve attached an article and an abstract (that article is in Japanese unfortunately … ) that do document that you CAN however on occasion find AIVR in otherwise healthy children — and I suppose that IS what we have here. Perhaps the circumstances surrounding the ED visit cause slight acceleration in the ventricular escape rate to allow this all to happen."

Here the full text of the article:

Accelerated Idioventricular Rhythm: History and Chronology of the Main Discoveries