An anonymous paramedic sent this.

A 60-something with past history only of colon cancer called 911 for non-specific generalized malaise.

The medics state that he was ill appearing.

They recorded an ECG:

What do you think?

This is extremely wide, and even if it is VT, it is so wide that there must be hyperkalemia or a severe Na channel blocking overdose.  The patient was not on a sodium channel blocker.

The paramedic knew instantly what it was (he credits his regular reading of this blog!)

The patient was only a couple blocks from the hospital, so there was no time for treatment before arrival.

K was 8.9 mEq/L.

Etiology was a combination of NSAID and obstructive nephropathy, with a Cr > 20 (!).  Estimated GFR of 2.0.

The potassium was brought down and the patient ultimately did well.