Wednesday, July 12, 2017

An 82 year old with syncope

An 82 yo male stopped for lunch after cycling. Witnesses reported a syncopal episode lasting approximately 30 seconds. He has a history of prior MI with 3 stents placed. There was no other significant hx. 

The patient denied any chest discomfort, dyspnea, or n/v or any complaints and did not wish to go to the hospital.  However, he did not protest transport.  

BP was 134/66, and heart rate remained around 60, which he said was normal for him. 

A 12-lead ECG was recorded:
Sinus rhythm, rate 64.
There are features here that one can recognize in retrospect, but in a patient with no current symptoms, it is all nonspecific.
For instance, there is a long ST segment and negative T-wave in lead III.  But the QRS axis is also negative, so not truly T-wave inversion.
Lead aVF has a very subtle up-down T-wave
There is a sagging ST segment in lead V3

The medic is very good at recording serial ECGs, and did so this time at 9 minutes even though there were no new symptoms (patient asymptomatic).
Sinus rhythm.
Note there is new ST elevation in lead II, aVF, V5, and V6.
There is also increased sagging of the ST segment in V1-V3.
The computer surprisingly reads "Meets STEMI critiera" !!

The ECG does not, strictly speaking, meet STEMI criteria: note on the side there are measurements of ST elevation at the J-point: it is correctly reading more than 1 mm ST elevation in 2 leads (II and V5), but these are not consecutive leads. STEMI criteria require the findings to be present in at least 2 consecutive leads. 

The medic was now very worried in spite of absence of symptoms, and recorded another ECG 6 minutes later:

Now the T-wave in lead III is much less negative.
There appears to be LESS ST elevation in II, V5, and V6

The medic noticed these dynamic findings and activated the cath lab!  

They were headed to a non-PCI center, so activating meant activating a transfer.  But they were too close to bypass the smaller hospital, so they stopped and the patient had an immediate ECG in the ED, still with no symptoms!!:
Atrial flutter with slow and variable conduction
Obvious inferior - posterior - lateral STEMI
Note that inferior T-waves have "pseudonormalized" (become upright)
See here for more on pseudonormalization

The patient was immediately transported to the PCI hospital, where an ostial RCA 95% thrombotic occlusion was found and opened and stented.


Should we get serial ECGs on asymptomatic syncope patients?  Maybe.  The literature on serial ECGs, which is pretty old, would say that among patients who are unlikely to have ACS, or at least dynamic ACS, it takes more resources than it is worth.  One should clearly get serial ECGs on a patient with ongoing chest pain, but for a single episode of syncope without ongoing symptoms?  

But in the ambulance, the ECG leads may remain attached, so why not record multiple tracings?

In contrast, in the ED, there is much demand for the ECG machine and tech, and it is more use of resources to keep the machine attached and record multiple tracings, so I would not advocate for that.

Learning Points

1. If it does not strain resources, record serial ECGs whenever there is any suspicion for ACS.

In this case, suspicion was very low but the medic is an incredibly skilled ECG reader (I know him) and he noticed these slight abnormalities which made him record more and then activate the cath lab.

2. In this case, the computer was very sensitive for STEMI.

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