Dawn's picture

This series of three ECGs is from a 75-year-old woman who came to the Emergency Dept. with chest pain.  The first ECG shows ST elevation in V1, V2, and V3, with generally low voltage in the QRS complexes. There is some coving upward of the ST segment in aVR, which can suggest a very proximal lesion of the left coronary artery (LCA).  She was taken to the cath lab, where it was discovered that she had a 100% occlusion of the midportion of the anterior descending branch of the left coronary artery, which was repaired and stented.  The second ECG, taken after the angioplasty, shows some Q waves in V1 and V2, with poor R wave progression in the V leads.   A 25% occlusion of the obtuse marginal branch of the circumflex artery was stented two days later. The third ECG was obtained after that procedure.  It shows that the Q waves have disappeared in the anterior leads (possibly due to different technicians performing the ECGs with different lead placement).  It also shows marked T wave inversion in I and aVL, representing ischemia in the lateral wall, and in all the chest leads, representing ischemia in the anterior wall.  The QTc is prolonged in this third ECG at 479 ms.  It is not known what medications the patient was on.  This patient also had a 50% proximal occlusion in the RCA and a 75% occlusion in the posterior descending artery.   This is a good example of a patient with extensive coronary artery disease who finally presented for treatment when she developed ST elevation M.I.  

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ekgpress@mac.com's picture

     This case is interesting for the changes in these 3 serial ECGs. It is also interesting in that we KNOW cath findings and find ourselves almost backward trying to correlate what we see on which tracing given what was found on cath ....

Remarkable findings in ECG #1 include:

  • Sinus rhythm with a PAC (7th beat on the lead II rhythm strip).
  • Low voltage - which IS relevant, as I believe the very low amplitude complexes in V2,V3,V4 reflect the ongoing anterior STEMI.
  • Marked anterior ST elevation in V1,V2,V3. Note that T waves are hyperacute in V2,V3 and probably V4 (disproportionately broad wrt the small amplitude QRS - and seemingly "trying to pull up" the ST segment more than it is).
  • There is also coved ST elevation in lead aVR. Although true that ST elevation in lead aVR often suggests proximal LAD occlusion (when there is anterior ST elevation) - I think it more likely in this case that the ST elevation in aVR is more of a reflection of this patient's diffuse multivessel coronary disease. This is because there is absolutely no ST elevation at all in lead aVL, which is usually elevated with LAD occlusion proximal to takeoff of the 1st Diagonal vessel.
  • Some reciprocal ST depression is noted in other leads - though one might have expected more ST depression given the acuity of ST segments in the anterior leads.
  • CATH showed mid-LAD occlusion - which is consistent with marked ST elevation in V1,V2,V3 but not in aVL.

ECG #2 - was obtained after cath and stenting of the mid-LAD 100% lesion. Remarkable findings include:

  • Significant reduction in the amount of anterior ST elevation. ST segments are no longer hyperacute.
  • A QS complex has formed in lead V2. That this IS significant can be determined from the loss of R wave between V1-to-V2. Given the amount of anterior ST elevation in ECG #1 - it is not surprising that infarction looks to have occurred (with development of the QS in V2).
  • Note persistence of ST coving and elevation in lead aVR (perhaps providing additional support to my theory that for this patient the ST elevation in aVR reflects diffuse severe CAD rather than acute LAD occlusion).

ECG #3 - was obtained 2 days later after stenting of a branch of the Circumflex artery (I'm not sure we know full circumstances of this - as normally a 25% lesion as is mentioned would not be stented ... ). Remarkable frindings on ECG #3 include:

  • Return of R waves in the anterior leads! Although possible that this is "technical" (due to lead placement) - my HOPE would be that it is a result of successful early stenting of the 100% mid-LAD lesion, suggesting that perhaps not that much myocardium was lost after all ....
  • There is diffuse precordial ST segment coving and deep, symmetric T wave inversion with QT prolongation - seen best in V2-thru-V4. While symmetric T wave inversion may indeed reflect ischemia - perhaps it is more a marker of evolution and reperfusion in the extensive anterior territory that recently infarcted. Although important to inquire about drug use with this new QT prolongation - it may be that the QT has lengthened as part of the evolutionary process. It sounds like acutely narrowed lesions have been treated (stented) - symptoms have resolved - and hopefully a good therapeutic result has been obtained given lack of anteroseptal Q waves on this 3rd tracing.

Ken Grauer, MD  www.kg-ekgpress.com   [email protected] 

Dawn's picture

So true, Dr. Grauer, the 25% lesion would not warrant another procedure. Alas, even though I took care of this patient in the recovery area of the cath lab, I can't remember all the details. On review of the notes I hastily wrote on the ECGs that day, the second procedure was shunting of the circ. I know her RCA had serious lesions, but I believe that was addressed at a later date. I will return to the cold, dusty vault, and see if I can find images of one or both caths. 

Dawn Altman, Admin

ekgpress@mac.com's picture

NOT a problem Dawn! I have too-numerous-to-count tracings "in the file" that years after are lacking in details of their occurrence. I just wanted to make the point that other circumstances (beyond a 25% lesion) must have been present to prompt the 2nd procedure. That said - this is a GREAT case, and so nice to be treated to serial tracings and definitive cath results. THANK YOU!

Ken Grauer, MD  www.kg-ekgpress.com   [email protected] 

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