Could it be uni224f, "Difference Between"?

I have next to zero knowledge of cardiology and/or mathematics, but I've never seen this either. What does it mean here? Just "beats at" or something more specific to fibrillation? Does it appear anywhere else? Is there a table of symbols?

Edit/Afterthought: maybe it's a clever representation of a P wave on an EKG? :)

I think it just means "approximately equal to" -- an alternative to the probably more commonly used ≈. (But there may be some subtle distinction of meaning between them that I'm not aware of.)

It's 264e, Libra. Unless it has an obscure usage in cardiology, it is probably being misused for 2245 (equal with a tilde over it) or 2250 (equal with a dot over it), which are other common "approximately equal" symbols.

Great stuff, thanks everyone!
I would never have figured this out on my own.

I'll get my client to check with the professor/s who provided the copy.

Based on the meaning of the text, it should probably be "less than or equal to": ≤

If the text was originally handwritten by a doctor, and there was no pharmacist available to interpret, that would explain the discrepancy.

Yes, of course, Libra! Good catch, I knew I'd seen this somewhere before :)

Nick: The symbol appears twice in the picture (scroll to the right!), and in the first sentence "more than or equal to" would make more sense. So it's probably just "approximately equal to".

Right. Copy this Jabez: ≈

Got it, thanks!

I went back to the client with the various suggestions.
No explanation was offered as to how it happened, but Cerulean got it right! Thanks for the rescue, everyone.

It was ≅2245. (Approximately equal to)