ST Depression Seen While scrolling through ECGs -- What is it?

This is a good one for residents and students! 

I was reading ECGs on the system and saw this one.

What do you think?

When I subsequently went into the chart, what do you think I was looking for?

This ECG is all but diagnostic for Digoxin effect.  There is atrial fibrillation, which explains why the patient would be prescribed Digoxin.  There is scooped ST depression in multiple leads, nearly pathognomonic of Digoxin, and the ST depression in accompanied by a short QT interval.

So to confirm, I went to the chart and, sure enough, he was on digoxin.  

These findings are seen at therapeutic levels. The ECG findings are not suggestive of digoxin toxicity.  

Then I realized that this patient was in triage, complaining of weakness. 

I ordered a chem panel and a digoxin level.  The creatinine returned elevated, raising suspicion of digoxin toxicity (as it is cleared renally), but the digoxin level returned at a therapeutic level.

In the setting of a normal QRS (no LBBB, no LVH, no RVH, no RBBB, no WPW), ST depression is a result of 4 categories:

1. Ischemia (Subendocardial or reciprocal to STE elsewhere -- including V1-V4, reciprocal to the posterior wall)

2. Hypokalemia

3. Digoxin

4. Benign baseline

Only Digoxin has a short QT interval

See other cases of Digoxin effect here: 

http://hqmeded-ecg.blogspot.com/search/label/digoxin