A 60-something year old man with chest pain and a wide QRS

Written by Pendell Meyers, with edits by Steve Smith

A man in his 60s with history of CAD s/p PCI, HTN, presented with chest pain which started while doing construction on his house several hours prior to arrival.

Here is his ECG on arrival at 2052:

What do you think? Should you activate the cath lab?

Yes, because there is an acute coronary occlusion causing OMI of the inferior wall. This is evident based on the LBBB with excessively discordant STE in leads II, III, and aVF, with reciprocal findings in I and aVL.

But the current guidelines do not use the modified Sgarbossa criteria, but rather the original Sgarbossa criteria. Because the STE in the inferior leads does not meet the 5mm threshold, it is negative by the original Sgarbossa criteria, as there is no concordant STE or STD.

The patient was given ASA and NTG drip with improvement but not full resolution of pain.

Initial troponin T was undetectable.

Troponin T at 2200 was 0.10 ng/dL (elevated).

Here is his repeat ECG several hours later at 0022:

There has been interval marked improvement of OMI findings, implying the artery has reperfused.

 Another repeat at 0248:

Still no signs of reocclusion.

Troponin T at 0306 was 0.80 ng/dL.

Troponin T at 0649 was 1.60 ng/dL.

The patient was admitted to cardiology for urgent cath.

1629: Cath shows an acute thrombotic ostial RCA in-stent restenosis culprit, 95% stenosed at the time of cath with TIMI 3 flow. Stent placed with good angiographic result. He also had a 70% chronic mid LAD stenosis, as well as 30% LCX.
Left main, LCX, and LAD, no large vessel occlusions.
LAD lesion described above.
RCA showing 95% ostial stenosis immediately after the tip of the catheter.
Another view showing the ostial RCA stenosis.
Intervention on ostial RCA lesion underway.
Post intervention with good angiographic result.
Troponin T peaked at 3.75 ng/mL the next morning (large MI). The characteristics of this lesion and the highly elevated troponin meet our definition of acute coronary occlusion surrogate criteria (when the angiogram is not performed at the time of the occlusion) used in the derivation and validation of the modified Sgarbossa criteria studies.

I looked back in the chart and found an almost identical presentation 4 years prior. He presented at that time with chest pain.

Presentation ECG at 2317:

Even more obviously positive for the modified Sgarbossa criteria with very excessive discordant STE in II, III, and aVF, with reciprocal findings in aVL and I. Notice how the original Sgarbossa criteria are falsely negative in this case both times.

0124
Cath showed a 90% in stent thrombosis in the proximal RCA, described as “severely thrombotic.” TIMI flow was increased from 2 to 3 after intervention.

0253

Findings resolving.

0937

Ongoing resolution with a hint of terminal T wave inversion in the inferior leads.

Serial Troponin T rose from undetectable to 3.63 ng/dL over the course of about 16 hours.

Learning Points: 

Use the modified Sgarbossa criteria to look for OMI in LBBB. The modified criteria are more sensitive than the original criteria as evidenced by cases like this.

Just because there is not complete occlusion at the time of cath does not mean there wasn’t complete occlusion at the time of the ECG prior to cath. This is why we have criteria for OMI when the angiogram is not performed at the same time as the ECG evidence of occlusion. Finally, complete transmural ischemia (what happens when there is OMI without collateral circulation) does not even require complete occlusion. A near-occlusion with TIMI 1 flow without collateral circulation may result in similar amount and speed of myocardial loss, and therefore similar benefit of immediate reperfusion therapy until proven otherwise.

Unlike most diagnostic tests, the modified Sgarbossa criteria are also more specific than the unweighted Sgarbossa criteria.  It is unusual to find a test that is both more sensitive and specific than the original test, but this is one.  
Here is the table from the validation cohort:
Compare lines 1 and 4

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