QRS complex

The standard STEMI millimeter criteria can miss a substantial subset of ACS cases.

And that's just because it's a very, very specific criteria where OMI looks at features beyond those traditional ST elevation thresholds and includes things like hyperacute T waves, pathological Q waves, terminal QRS distortion, as well as reciprocal ST depression and or T wave inversion.

It also picks up subtle ST elevation that doesn't quite meet the criteria and this is probably another thing we should have touched on in treatment is about doing reciprocal and repeat ECGs because what we want to do is look for those small changes that start evolving and become dynamic changes and then we can pick an occlusive MI up in the really early phases and identify it before it does turn into that really large obvious occlusive event.

And sometimes that might be something as subtle as we call them hyper acute T waves, but you might have hyper acute T waves in your inferior leads.

So if, you know, even if this patient didn't have an ECG showing an occlusive MI, I think the approach would be very much the same just other than that they, you know, aren't going to get that specific PCI treatment in the, in the immediate, they're going to get assessed, get things like troponins done and the like, but I would approach it fairly similar.

It's a pretty good standard of care to have.

And I think You know, we gave a lot away as far as history goes during this assessment, but it's just doing a really thorough assessment using, you know, your acronyms like OPQRST for pain, sample for your history and sticking with that, you know, ABCDE kind of approach.

Cool.

It was a non-inferiority margin, and the margin they chose was minus 10% points, and it was an intention to treat primary analysis.

Secondary endpoints were left ventricular ejection fraction, QRS duration, NT-proBNP symptoms, six minute walk, capture thresholds, and device implant measures.

Crossover was permitted.

So let's talk about the crossover part.

Now, let's shift gears to another cation, which is primarily intracellular, and it is called potassium.

Now, an oliguric child has severe hyperkalemia and a widening QRS interval on their EKG.

Which treatment protects the myocardium immediately? A, insulin with glucose.

B, intravenous calcium.

So basic metabolic panel is what carries a lot of our electrolytes when we're taking a look at it in there.

And certainly you see certain EKG findings that are characteristic of certain conditions, right? So we always learn about hyperkalemia, how it stretches out that QRS complex.

Eventually you can get a sine wave, right? in severe states.

Your EKG is very, very sensitive at picking up electrolyte abnormalities.

Okay.

I thought he was

asking something about the mic, but he was actually making a QRS and his fingers.

This is sodium, magnesium and potassium.

First up, EKGs and halters.

89% were in sinus rhythm or in atrial rhythm, and the authors state that in the final decade, meaning between 40 and 50 years post-op, 13% developed prolongation in the QRS duration to over 120 ms. Holter monitors showed some form of SVT in 69%, with the majority being very minor short atrial tachycardia runs.

However, AFib was seen in 2 or 4%, and non-sustained VT, defined as 3 to 10 complexes, were seen in 7% or 4 patients.

But there was no sustained VT in any patient.

So the P wave represents the depolarization of the atria, that initial spark spreading across the top chambers.

Then you have the QRS complex, that massive spiky mountain on the graph.

That represents the depolarization of the heavy muscular ventricles.

Finally, the T wave represents the repolarization or the electrical resetting of those ventricles.

Yeah.

And because the ventricles have so much more muscle mass, their electrical signal is huge.

The atrial resetting signal is just completely buried inside that massive QRS complex.

The machine simply can't see it over the noise of the ventricles firing.

That's our cardiac output.

Now, on the monitor, that shows up as a narrow QRS complex, that big spike that basically tells us, hey, the ventricles just squeezed.

Narrow is the key word here.

Narrow means that it was equal.

They squeezed.

They moved blood forward.

Narrow QRS is what we want.

Make sure to remember that.