Every once in a while you wonder if people actually understand what they are dealing with and whether or not they really understand what's going on. A recent encounter with another physician perplexed me.

A patient is brought to the ER because he or she is found unconscious by a family member. It turns out the EKG looks "scary" and they call cardiology. What the ER thought they saw on the EKG was an entity called "ST Elevations" which typically means someone is having an acute heart attack and needs to go to the cath lab to get the artery opened up.

We arrive. It turns out the patient is in acute renal failure, with a creatinine of 3.5, the potassium is over 8 (which gives you a similarly bizarre EKG pattern), and has a blood sugar of over 1300, and a bicarbonate of 5. The ER also ordered a troponin which was indeterminant and a BNP which was 1300.

The patient on paper looks like he is in Diabetic Ketoacidosis, dehydrated as hell, and has gone into acute renal failure from the severe dehydration. Yes, the elevated potassium is very high and at such high levels you get EKG changes which look very abnormal. A potassium over 7.5 gives you wide QRS complexes, wide T waves (the QRSs and Ts look similar), lack of P waves (or very blunted), bradycardia. 

We rehydrate the patient, his potassium quickly comes down (as is expected, because they are really potassium deficient), treat his DKA, and over the next few days his kidneys resume normal function.

A few days later one of the physicians from the ER saw me in the hallway and asked me, "Hey, how do you explain the CHF in that guy?"

I asked, "CHF? Why do you think he was congested? You think he is volume overloaded?"

"His BNP was like 1300"

"He was in acute renal failure."

"So, why was he volume overloaded?"

"He wasn't. He was about as dry as they come. You coulda given him 10 Liters and he'd be fine."

"And the BNP?"

"You can't really evaluate a BNP with renal failure. Nor troponin for that matter. Just toss those two out the window."

Sometimes you just think to yourself, "Wow!" Sometimes things that you think are common knowledge may not always be. We can't rely on merely tests and numbers. We can't be robots. We have to understand what happens behind the numbers.

Medicine humbles you every day! There isn't a day that goes by that I don't learn something new.

One of the most important things to learn about medicine is how to know when someone is really having a heart attack. Especially, a STEMI (ST Elevation Myocardial Infarction). Those are the deadliest and heart muscle has died and is dying as we speak.

If you learn anything in all of medicine, please learn to recognize a STEMI. Why? STEMIs have to go to the cath lab and the artery needs to be opened up within 90 minutes. That saves heart muscle and saves lives!

 Below is a quick review of all the various parts of an EKG. We are mainly looking at the ST segment.

So what is a STEMI?

STEMI criteria:
The ST segment of an EKG will be elevated by more than 3 mm in the precordial leads and by more than 1 mm in the limb leads. Further, in the precordial leads, the shape should be convex up (like a tombstone). The shape matters more than the amount of elevation in some cases. You may have minimal elevation, but the shape is convex up, that could be considered a STEMI.

In the limb leads, the shape does not matter, just the elevation. Anything more than one small box, and you have a STEMI! Pretty straight forward. Unless, of course, it is an early repol!

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