Wednesday, December 16, 2020

Extreme widespread ST depression, with ST Elevation in aVR. What do you think?

 I was texted this ECG without any other information.  The question was posed: "Activate the cath lab?"


What do you think?

What was my answer?












There is diffuse ST depression due to widespread severe subendocardial ischemia.  The ST elevation in aVR is reciprocal to that ST depression.

Smith answer: "Of course there is severe ischemia.  But the question is: Is it due to acute coronary syndrome?  What is the clinical situation?"

Clinical history

This is a young homeless intravenous drug user who presented with chest pain, nausea and vomiting, chills and a left foot wound.  He was hypothermic with a blood pressure of 98/19.  

What do you think now?

With the wide pulse pressure and extremely low diastolic pressure, aortic regurgitation (insufficiency), probably from endocarditis, was immediately suspected and confirmed with bedside echo with doppler.  Other etiologies of low diastolic pressure and high pulse pressure include anything that causes severely decreased systemic vascular resistance, though few such entities are this profound.  

Remember that the coronaries are perfused by diastolic aortic pressure. During systole, the LV intraventricular pressure is high and prevents perfusion. (The exception is the right ventricular coronary branches, which are perfused in systole as well because RV pressure is lower than systolic pressure).  Aortic regurgitation greatly decreases diastolic aortic pressure, and increases diastolic LV pressure, so that there is very little flow in the coronaries with such a low diastolic pressure, and the worst location of that ischemia will be adjacent to the LV cavity, which is the subendocardium.

In spite of maximal medical therapy and planning for immediate surgery, the patient died.

This case was obviously not ACS, and my partners knew it all along.  They just wanted to see what my reaction to the EKG would be.

Learning point

Most widespread ST depression, with STE in aVR is NOT due to ACS.  See 2 papers referenced below.

The differential diagnosis for widespread ST depression with STE in aVR is anything that can cause supply demand mismatch.  So anything that   Some important ones are listed here:
1. Valvular disease
2. Severe anemia
3. Severe hypoxia
4. Hypotension, especially diastolic hypotension
5. Hemoglobinopathies or cellular toxins
6. Severe LVH or HOCM, which prevents adequate perfusion
7. Extreme tachycardia
8. Extreme hypertension
9. Lesser degrees of any of the above, if combined with fixed coronary stenoses.

Acute coronary syndrome.  Severe Left Main stenosis (not occlusion!) or LAD, or single vessel ACS with 3 vessel disease.

The ECG does not differentiate the above etiologies, it simply signifies that there is severe diffuse global supply-demand mismatch, whatever the etiology.

LVH, LBBB, RBBB, and RVH may manifest ST depression without any ischemia

Other cases:
Aortic Stenosis:


An elderly man with sudden cardiogenic shock, diffuse ST depressions, and STE in aVR

Literature

1. Knotts et al. found that such ECG findings (STE in aVR) only represented left main ACS in 14% of such ECGs: 

Only 23% of patients with the aVR STE pattern had any LM disease (fewer if defined as ≥ 50% stenosis). Only 28% of patients had ACS of any vessel, and, of those patients, the LM was the culprit in just 49% (14% of all cases).  It was a baseline finding in 62% of patients, usually due to LVH.

Reference: Knotts RJ, Wilson JM, Kim E, Huang HD, Birnbaum Y. Diffuse ST depression with ST elevation in aVR: Is this pattern specific for global ischemia due to left main coronary artery disease? J Electrocardiol 2013;46:240-8.

2.  Now there is a paper published in 2019 that proves the point beyond doubt, though makes it clear that this pattern is associated with very high mortality.

https://www.sciencedirect.com/science/article/abs/pii/S000293431930049X
Harhash AA et al. aVR ST Segment Elevation: Acute STEMI or Not? Incidence of an Acute Coronary Occlusion.  American Journal of Medicine 132(5):622-630; May 2019.

Here is the abstract:

Background
Identification of ST elevation myocardial infarction (STEMI) is critical because early reperfusion can save myocardium and increase survival. ST elevation (STE) in lead augmented vector right (aVR), coexistent with multilead ST depression, was endorsed as a sign of acute occlusion of the left main or proximal left anterior descending coronary artery in the 2013 STEMI guidelines. We investigated the incidence of an acutely occluded coronary in patients presenting with STE-aVR with multilead ST depression.

Methods

STEMI activations between January 2014 and April 2018 at the University of Arizona Medical Center were identified. All electrocardiograms (ECGs) and coronary angiograms were blindly analyzed by experienced cardiologists. Among 847 STEMI activations, 99 patients (12%) were identified with STE-aVR with multi-lead ST depression.

Results

Emergent angiography was performed in 80% (79/99) of patients. Thirty-six patients (36%) presented with cardiac arrest, and 78% (28/36) underwent emergent angiography. Coronary occlusion, thought to be culprit, was identified in only 8 patients (10%), and none of those lesions were left main or left anterior descending occlusions. A total of 47 patients (59%) were found to have severe coronary disease, but most had intact distal flow. Thirty-two patients (40%) had mild to moderate or no significant disease. However, STE-aVR with multilead ST depression was associated with 31% in-hospital mortality compared with only 6.2% in a subgroup of 190 patients with STEMI without STE-aVR (p less than 0.00001).

Conclusions

STE-aVR with multilead ST depression was associated with acutely thrombotic coronary occlusion in only 10% of patients. Routine STEMI activation in STE-aVR for emergent revascularization is not warranted, although urgent, rather than emergent, catheterization appears to be important.




9 comments:

  1. There is st elevation on v1 and st depression on v3. V2 is almost isoelectric which may be ommitted by counter forces of elevation and depression. Why dont we consider acute posterior and right stemi in this case? This may be a septic emboli Sure emergent cath lab activation may be mandatory and patient may have lmca lesion

    ReplyDelete
    Replies
    1. It is the clinical situation which illuminates the ECG. The ECG must always be interpreted in the clinical context, and this clinical context and ECG point to aortic insufficiency.

      Delete
  2. Wow! Thank you for this post. Will be sharing the case with my Cardiology colleagues. Great to have the references too.

    ReplyDelete
  3. Have you considered coronary embolism?

    ReplyDelete
    Replies
    1. Great idea, from endocarditis. But the diastolic pressure explains everything, unless both are happening at the same time.

      Delete
  4. V3 looks to have max STD. This would have stumped me and I would have probably ventured down the trail of posterior MI simultaneously in the presence of subendocardial ischemia.

    ReplyDelete
    Replies
    1. I think it is max in V4. Nevertheless, I agree it can be confusing.

      Delete

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