Thursday, April 14, 2011

Marked ST depression refractory to maximal medical therapy

This 62 year old man, heavy smoker, with no previous medical history, presented after 2.5 hours of substernal chest pressure.   He stated he had been having chest pressure with exertion for one month.

His prehospital ECG (I cannot find them) showed marked ST depression in V2-V6, with 1 mm ST elevation in aVR.  He received 3 sublingual NTG in the ambulance with improvement of pain, but no resolution.  He received a 325 mg aspirin.

On arrival, BP was 130/70.   A nitro drip, heparin bolus and drip, and eptifibatide bolus and drip were started.

This is his second 12-lead ECG.  I will shortly post his initial ECG which I have had a hard time locating.  Here there is less ST depression than in the prehospital ECGs and less STE in aVR.  But there is ongoing ischemia.

Sinus rhythm with slightly wide QRS, ST depression in V2-V6 (less than prehospital ECGs) and 1 mm ST elevation in aVR.
You can read more about STE in aVR.

If there is at least 1 mm of STE in aVR, 3-vessel disease or left main disease is likely, and CABG is the likely outcome.   Therefore, do not give clopidogrel which results in unacceptably high CABG bleeding risk for 5 days.

After titrating IV nitroglycerin to 180 mcg/min, the chest pain was gone and the BP was 100/60. However, there remained ST depression:
Sinus rhythm with slightly wide QRS, ST depression in V2-V6 (less than prehospital ECGs) and now minimal ST elevation in aVR.

Chest pain is not a sensitive indicator of ischemia; the ECG established ongoing ischemia in spite of resolution of chest pain.


Thus, the patient had ACS with ischemia refractory to maximal medical therapy.  It is important to note that aVR does not count as an ST elevation indication for thrombolytic therapy.  But refractory ischemia is an indication for emergent angiography with possible PCI.  I called the interventionalist and he agreed, however the patient refused to go.

He was admitted to the ICU.  His troponin peaked at 7.0.  He continued to have ST depression the next AM, at which time he agreed to cath, which showed 100% RCA (probably chronic), 99% LAD, and 95% Circumflex disease.  A balloon pump was placed, with subsequent resolution of ST depression.  He went for 3 vessel CABG, and immediately after coming off pump, his ejection fraction was greatly improved, the balloon pump was removed, and he is doing well.

Here is the postoperative ECG:

4 comments:

  1. Interesting that he had so much stenosis yet only relatively minor ECG changes!

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  2. They weren't quite as minor on the prehospital ECG, and one must remember that ST depression > 2 mm carries very high mortality. In the years before PCI, ST depression of at least 2 mm in at least 2 leads had a 30-day mortality of 35%, higher than that of untreated anterior STEMI!

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  3. Dr. Smith,

    I read an article linking elevation in aVR with STD in I, II, and V4-V6 is highly sensitive for three vessel disease or an occlusion of the LMCA. Almost all patients required CABG. It had 81% sensitivity, 80% specificity, and 81% accuracy.

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  4. Yes, I posted the reference to that article in this case discussion: http://hqmeded-ecg.blogspot.com/2011/04/st-elevation-in-avr-with-widespread-st.html

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