Wednesday, November 18, 2015

Formula positive for LAD occlusion. But echo shows no wall motion abnormality! What is it?

Dr. Josu Abecia Valencia, from Spain, asked me my opinion on this case.  He has a great Spanish language blog.  You can find this case in Spanish at his blog here: https://urgenciasbidasoa.wordpress.com/2015/11/16/caso-201-varon-de-35-anos-con-dolor-toracico-de-10-horas-de-evolucion/

He gave his permission for me to post it here.

A 35 year old complained of typical substernal chest pain:
What do you think?
My opinion is below.
Notice the computer reads early repolarization.
















Here is my response:

Dr. Abecia,
This is highly suspicious for LAD occlusion, though not diagnostic.
Have you used my formula?
ST elevation at 60 ms after the J point in lead V3 = 4 mm
computerized QTc = 405
R-wave amplitude in V4 = 14.5 mm
Formula value = 23.9, which is > 23.4 which is pretty specific for LAD occlusion.

I would do frequent serial EKGs, every 15 minutes, for several hours.
I would do an emergent formal contrast echocardiogram.


If still non diagnostic, consider immediate angiography.

What was the outcome? 


Here is the outcome (slightly limited because I don't read Spanish very well):

Time zero: Troponin T drawn, returns later at 43 ng/mL (slighlty elevated)
Serial EKGs unchanged.
Thoughts: myopericarditis vs. early repolarization vs. possible MI
Time 5 hours: Troponin T returns at 151 ng/mL.
Still thinking myocarditis
Time 11 hours: Troponin T returns at 350 ng/mL
Echo shows EF of 67% and no Wall Motion Abnormality

But symptoms persisted, and with the positive troponin, they sent him for angiogram.  Here are the results:
Occlusion of the very distal LAD.  So in this case, it was a small infarct territory.
The thrombus was suctioned out and it was stented.
Symptoms resolved.



The formula to differentiate benign ST elevation from LAD occlusion worked perfectly, even though it was a small anterior MI.  It outperformed serial ECGs and formal echocardiogram.

One might argue, with good rationale, that such a small MI can wait until the next day for angiogram.  I will not oppose the argument strongly, but the patient did have ongoing chest pain that was relieved by intervention.  

2 comments:

  1. Hello Dr. Smith,

    I am really curious about and needed to clarify a point: This patient has acute chest pain, ECG is pretty diagnostic for the readers of this blog, your formula indicates anterior STEMI, yet you commented "This is highly suspicious for LAD occlusion, though not diagnostic"... "Formula value = 23.9, which is > 23.4 which is pretty specific for LAD occlusion." and I puzzled to read that "I would do frequent serial EKGs, every 15 minutes, for several hours."

    Why did you render this ECG suspicious but nondiagnostic ? Is it nondiagnostic according to general ACC/AHA 2 mm STE criteria or according to your gestalt ? I am asking because you have brilliantly presented so subtle cases to date and advocated to press on these subtle findings. But many of the readers will be really hesitant in such circumstances, if you yourself say "I would do frequent serial EKGs, every 15 minutes, for several hours."

    I really would like to learn and greatly appreciate it if you could give a general outline (may be a short lecture) of YOUR diagnostic criteria (readers of these blog would not care about usual ACC/AHA criteria). I saw some examples in this blog in which you seemed to be sure about the diagnosis from the very beginning, but searched for more evidence (may be to prove it to your interventionalists?). For what extent and for which subtle findings would you render an ECG sufficiently diagnostic or highly suspicious and needs more evidence (Of course, pretest probability is important, but just focusing on ECG). If you mind considering a post about general classification (high specificity (no need for more evidence) and moderate specificity (needs more evidence)) of these subtle findings (readers of this blog would know what are they), we would be really grateful.

    Thanks in advance

    ReplyDelete
    Replies
    1. Emre,
      All good questions.
      It all depends on:
      1. one's own confidence in the diagnosis
      2. the responsiveness of one's interventionalist/cardiologist
      3. the pretest probability of the patient (age, type of symptoms, etc.)
      4. Also, with subtle occlusion, one is not bound to a short door to balloon time, but has a bit more time to be certain of the diagnosis. There will always be false positives and if you have one, and your cardiologist don't trust you, their trust in you will fall off quickly.

      If I think it is an occlusion, I activate. But my cardiologist trust my opinion more than their own.

      thanks!
      Steve

      Delete

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