Monday, 8 November 2010

47 year old female CC: Chest pain - Discussion

Obviously, this is a scary looking ECG because there is significant ST-elevation in the precordial leads.

However, this ECG also meets the voltage criteria for LVH.

Could it be a strain pattern (typical secondary repolarization abnormality)?

No.

It's difficult to tell with the wandering baseline throughout this ECG, but if you line up the point at which the PR-segment hits the QRS complex in leads V1, V2, and V3 you can see that each of these leads shows approximately 4 mm of ST-elevation.



You will recall that with a "strain pattern" the degree of ST-elevation is proportional to the depth of the S-wave in the opposite direction! So the lead with the deepest S-wave should have the most significant ST-T wave abnormality in the opposite direction.



It's not easy to tell the exact depth of the S-wave because the complexes are running together, but these measurements are probably fairly close.

There's no way that a typical strain pattern would show the same amount of ST-elevation in one lead with S-waves that are 22.5 mm deep and another with S-waves that are only 6 mm deep.

Here's the most disturbing finding, in my opinion.



There appears to be reciprocal behavior between the inferior leads and the high lateral leads.

So, if this is a STEMI mimic (for example, benign early repolarization superimposed on top of left ventricular hypertrophy) it's a darned good one!

So what should the hospital do when they are in receipt of a patient like this?

I asked Stephen Smith MD from Dr. Smith's ECG Blog and here's what he said.
"If I were the ED physician, I would aggressively treat the blood pressure with NTG (up to 250 mcg/min or even higher) until the BP came way down. I would do a bedside cardiac ultrasound and look for anterior wall motion. If pain did not go away, and echo did not definitely show good wall motion, I would activate the cath lab."

It's always nice to get Dr. Smith's perspective! I've learned a lot from his blog over the past 2 years. If you're not familiar with his website you should take the time to check it out! His case studies are top notch!