http://hqmeded-ecg.blogspot.com/2010/01/deep-and-widespread-st-depression.html
However, because of a new article, I want to post it again.
The patient presented with chest pain and had this ECG which is a very high risk situation. There was a severe ostial LAD thrombosis that was very close to the left main. He went for emergent bypass that evening and had a good outcome.
ST elevation in aVR is often thought to represent left main occlusion. However, it really just signifies widespread and diffuse subendocardial ischemia which could be due to left main or 3-vessel disease, or severe proximal LAD disease. Left Main occlusion generally causes rapid death; most who survive left main ACS have some flow and thus often have widespread ST depression.
There is an important recent article relevant to this:
Kosuge M, Ebina T, Hibi K, et al. An early and simple predictor of severe left main and/or three-vessel disease in patients with non-ST-segment elevation acute coronary syndrome. Am J Cardiol;107(4):495-500.
They show that if there is not at least 1 mm STE in aVR, then ACS is highly unlikely to be due to severe 3-Vessel disease or Left Main. Why is this important? Because if such severe CAD is present, the patient is likely to need CABG. If they need CABG, then the surgeon will usually be unhappy if the patient received clopidogrel.
So, here is a potential strategy: if there is no STE in aVR, then you can safely give clopidogrel to this NSTEMI patient. If there is at least 1 mm STE in aVR, then a GP IIbIIIa inhibitor should be given instead.
In his publish book from 1992 "The ECG in Emergency Decision Making", Dr. "Hein" Wellens (Wellens Syndrome) and Mary Conover write in chapter 2 "ECG Identification of High-Risk Patients With Unstable Angina" on page 34:
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If there is St segment elevation in V1 and aVR plus ST segment depression in eight or more leads in a pateint with unstable angina, the chance of having severe left-mainstem or three-vessel disease is very high (71%).
In a study involving 125 patients with left mainstem disease, of the eight leads with St depression, the most frequenly involved leads were V3 to V5. Lead V4 showed the greatest amount of St depression (67% of patients).(1988)
Note: 25% of patients with as much as 91-99% occlusion of the left main coronary artery have a normal ECG when they are pain-free! It's therefore important to record the ECG during chest pain.
There are many studies since Wellens' wrote that, and the bottom line is that STE in aVR has different meaning in STEMI than it does in NSTEMI, that in NSTEMI (as in this case), it is not independent of ST depression, that it is an easy single ECG finding to look for, that it confers higher risk, higher mortality than patients who do not have [STE in aVR, ST depression], that it is associated not just with left main but also with 3 vessel disease (one cannnot tell the difference, nor is there a need to), and that it correlates with the need for CABG.
ReplyDeleteST elevation also in V1 besides aVR, but V2 appears normal. Could it be due to ST depression in V5 / V6?
ReplyDeleteV1 is opposite V5/V6 and therefore can show reciprocal ST elevation. V2 not so much.
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