Tuesday, June 21, 2011

Prehospital ST Elevation and pain resolve with NTG. ECG and Echo normal in ED.

The resolution of symptoms and the ECG in this case is similar to the last post, but the ST and T-wave morphology of the ECGs are quite different, and the outcome is remarkable.

65 yo male with h/o HTN, DM, and hyperlipidemia had onset of intermittent chest pressure and SOB at 2 AM.  He has never had anything like this and has no h/o CAD.  The pain is substernal and radiates to the left arm.  It is not reproducible, pleuritic, or positional.  It became much worse at approximately 1230 and he called 911.  Medics recorded this ECG with pain 10/10:
The computer calls this normal. The medics were worried about the ST elevation.  The ST elevation could be MI or early repol, though one should be skeptical of early repol in patients of more advanced age as it becomes much less common.  Additionally, there is straightening of the ST segments.  The early repol vs. MI "score," based on STE 60 ms after the J-point of 3.0 mm, QTc of 425 ms, and R-wave V4 of 17 mm, is 23.773 (greater then 23.4 is the best cutoff for MI).

He was given sublingual NTG, and his pain improved to 7/10 at 1303, to 3/10 at 1309, and to  1/10 at 1313 after a second NTG.

At each of these times, he had another ECG recorded by the medics, and the resulting decrease in ST elevation and T-wave amplitude is demonstrated here, with all of them side by side, including the 5th ECG recorded in the ED.  (I have also posted the entire 1st ED ECG, recorded at 1334, below this figure).

Here is the full 12-lead from the ED at 1334:
T-waves and ST elevation are subtly but significantly less pronounced.  ER vs. MI score is now 20.324 (STE V360 = 1.5 mm, QTc = 408, R-wave amplitude = 17)

A formal echo was done at 1349 which was entirely normal.  There was no anterior wall motion abnormality.  It was read by one of the most experienced echocardiographers anywhere.  Then his first troponin I returned at 0.18 ng/ml (0.10 is positive).

He was treated for NSTEMI.   Subsequent troponins every 4 hours were: 0.41, 0.90, 1.14, 1.18, 1.01, then 0.98.    Next day had angiography, which showed a 90% LAD stenosis (culprit) as well as severe 3-vessel disease.

He went for CABG on day 5, and this ECG was recorded after the operation:
There is new anterior infarction that has happened some time within the last few days.

A troponin I was measured at over 80 ng/ml, indicating that the infarct had occurred some time between admission and operation, probably before the operation.

1. Transient ST elevation is hazardous
2. Pay attention to ECG changes
3. After the ECG has normalized, the echo may normalize as well.
4. While in the hospital, such a patient should have continuous 12-lead ST segment monitoring.  It is likely that a repeat STEMI was completely missed while he was waiting for CABG.

No comments:

Post a Comment

DEAR READER: We welcome your Comments! Unfortunately — due to a recent marked increase in SPAM — we have had to restrict commenting to Users with a GOOGLE Account. If you do not yet have a Google account — it should not take long to register. Comments give US feedback on how well Dr. Smith’s ECG Blog is addressing your needs — and they help to clarify concepts of interest to all readers. THANK YOU for your continued support!

Recommended Resources