An 80 year old woman with Left Bundle Branch Block (LBBB) and pleuritic chest pain

This case was sent by Amandeep (Deep) Singh at Highland Hospital, part of Alameda Health System.

The patient presented to an outside hospital

An 80yo female per triage “patient presents with chest pain, also hurts to breathe”

PMH: CAD, s/p stent placement, CHF, atrial fibrillation, pacemaker (placed 1 month earlier), LBBB.

HPI: Abrupt onset of substernal chest pain associated with nausea/vomiting 30 min PTA.  She reports associated SOB but no dizziness or LOC.  She was given NTG at home before coming to the hospital.

 

This was the ECG obtained at triage.

This ECG was recorded and was reviewed remotely by a cardiologist:

What do you think?

Deep saw this later and thought this was clear inferior-posterior-lateral OMI.

He sent it to me with no other information and I wrote back "100% diagnostic of LBBB with inferior-posterior-lateral OMI"

---There is atrial paced rhythm with Left Bundle Branch Block (LBBB).  

1. There are hyperacute T-waves in inferior leads, with depressed ST takeoff (inferior de Winters -- yes, de Winter's can manifest in any territory and, yes, it can manifest in the presence of LBBB.)

2. There is concordant ST depression in V3.  It only takes one such lead to fulfill the 2nd criterion of the Smith Modified Sgarbossa criteria.

3. There are hyperacute T-waves in V5 and V6.

The Queen of Hearts agrees:

Here the Queen explains why:

However, it was not interpreted correctly by the providers:

ED interpretation of ECG: "paced rhythm, LBBB but no STEMI pattern."

Repeat ECG @ 30 min:

"no dynamic change"

1st Troponin (contemporary troponin I) below the limit of detection.

Case was discussed with cardiology who recommended admission, but did not want transfer to a PCI capable facility.  Cardiology documents their interpretation of ECG in their consult note - “atrial paced with old LBBB”

 

The patient stayed at outside hospital (which does not have cardiac cath capabilities).

Hospitalist assessment/plan - initial trop negative without ECG abnormalities; will admit to Floor bed with telemetry monitoring.  Next trop in AM.

 

1st trop – undetectable

2nd trop (11 hours after arrival) 31.281 ng/mL —> The elevated Troponin prompted cardiology re-eval and transfer to Highland Hospital.

Peak trop 257.97 ng/mL.  

Smith: This is an enormous myocardial infarction.   Most large STEMI have peak troponin I in the 20.0 ng/mL - 80.0 ng/mL range 

 

At Highland Hospital (prior to Cath)- 

Patient became altered.  She was noted to be tachypneic and hypoxic.  This was treated with furosemide and BIPAP initially but she soon required intubation for respiratory failure and to facilitate cardiac catheterization.

 

Cardiac catheterization occurred around 1pm (18 hours after arrival).  

The cath report showed: Significant stenosis with subtotal occlusion (99%) in the prox to mid Lcx, culprit of ACS, TIMI flow 1.  This was stented with a 2.25 x 38mm stent, post dilated with a 2.75mm balloon proximally.  

Additional findings included CAD in the distal LMCA (45%), patent prior stents in LAD and RCA, with mild restenosis in the LAD stent (25%) and moderate restenosis in the RCA stent (60%). 

 

Echocardiograpy

Normal global LVEF 50-55%

Mild concentric LVH

New regional wall motion dysfunction - basal/mid inferolateral, basal/mid anterolateral, apical lateral compared to ECHO 1 month earlier

Case discussion

Deep brought this case up for review at their cath lab QRC as an example of occlusive myocardial infarction that could have benefitted from earlier cardiac catheterization.  He remarked “Every cardiologist in the room disagreed with me.”  Several of them remarked that this ECG pattern could be a normal variant; and they also thought ‘cardiac memory’ could be at play (neither of which is true).

Smith: this ECG cannot represent a normal variant.  It is diagnostic of OMI.

Inability to recognize OMI in LBBB led to a poor outcome

Learning points:

1. Learn the findings of OMI

2. Learn the findings of OMI in LBBB (Smith Modified Sgarbossa criteria are most sensitive and specific) (1, 2)

3. Use the Queen of Hearts

4. Most cardiologists are not skilled at interpreting subtle OMI, even when the ECG is absolutely diagnostic.  If they do not see it, they will usually say that the ECG is "nonspecific".  This is only because their own interpretation is nonspecific.  NOT because the ECG is actually nonspecific.

1. Lindow T, Mokhtari A, Nyström A, Koul S, Smith SW, Ekelund U. Comparison of diagnostic accuracy of current left bundle branch block and ventricular pacing ECG criteria for detection of occlusion myocardial infarction. Int J Cardiol [Internet]. 2023;131569. Available from: http://dx.doi.org/10.1016/j.ijcard.2023.131569

2. Khawaja M, Thakker J, Kherallah R, Ye Y, Smith SW, Birnbaum Y. Diagnosis of Occlusion Myocardial Infarction in Patients with Left Bundle Branch Block and Paced Rhythms. Curr Cardiol Rep [Internet]. 2021;23:187. Available from: http://dx.doi.org/10.1007/s11886-021-01613-0

If you are wondering about the Barcelona rule, then you should read the above paper by Khawaja et al. and the following post.  The Barcelona rule was only derived, and the methods were incorrect.

Barcelona Rule on Left Bundle Branch Block: Lots of Issues.

 

The Queen of Hearts PM Cardio App is now available in the European Union (CE approved) the App Store and on Google Play.  For Americans, you need to wait for the FDA.  But in the meantime:

YOU HAVE THE OPPORTUNITY TO GET EARLY ACCESS TO THE PM Cardio AI BOT!!  (THE PM CARDIO OMI AI APP)

If you want this bot to help you make the early diagnosis of OMI and save your patient and his/her myocardium, you can sign up to get an early beta version of the bot here.  It is not yet available, but this is your way to get on the list.

https://share-eu1.hsforms.com/18cAH0ZK0RoiVG3RjC5dYdwfyfsg