I saw this in a stack of ECGs and recognized it immediately. 

What do you think?

There is ST depression in the context of a normal QRS.  In other words, the ST depression is not secondary to LVH, LBBB, RBBB, RVH, WPW, or LV aneurysm.

ST depression with a normal QRS has a small differential:

1. Ischemia

2. Hypokalemia

3. Digoxin

4. Normal variant.

5. Anyone have any others?

Ischemia has a relatively long QT interval

Digoxin results in a short QT interval.

Digoxin is also associated with atrial fibrillation, as we see here.

Digoxin ST depression has a “scooped” appearance.  It has been likened to Salvador Dali’s mustache (see below)

This ECG is pathognomonic for Digoxin effect, NOT toxicity.  

Dig level was 0.6 ng/mL (0.4-2.0 is therapeutic)

The patient had non-cardiac chest pain.

Salvador Dali’s mustache