Step 5: Examining the ST Segment (Nursing)

00:01 Ready for step five? We're going to look at the ST segment.

00:05 Now the ST segment is the early repolarization of the heart's chambers.

00:10 So look at the isoelectric line.

00:13 Remember depolarization is contract, repolarization is relax.

00:19 So we're looking at the ST segment, we've gone through the P wave, then the isoelectric line for a little delay, QRS and now we're talking about the ST segment.

00:33 So this segment lets us know how the heart has repolarized, it's the early part of that.

00:39 Let's remember the interval of time between the ventricular depolarization and repolarization.

00:46 That's what's reflected as the ST segment.

00:48 And because during this amount of time, there is no impulse activity in the heart, the segment should be reflected in the ECG strip as a flat isoelectric line.

00:58 Now, elevations and depressions of the ST segment could be a sign of cardiac problems, like myocardial ischemia.

01:06 Okay, I have a 12-lead here again, because I just want to remind you, if you see an elevated ST segment when you're doing a regular ECG, lead II kind of strip, then you know, the next step will be to order a 12-lead ECG.

01:22 You want to take a look at that, because they're going to want to look at the heart in all different kinds of leads.

01:28 So why is everybody getting so excited about that ST segment elevation? because it's an indication that the patient could be having a myocardial infarction.

01:38 You'll hear people call it a STEMI.

01:41 STEMI is not the news anyone wants to get about themselves or their patient.

01:46 STEMI stands for ST-elevated myocardial infarction, and NSTEMI would be a non-STEMI or a non ST-elevated myocardial infarction.

02:00 So all you have to keep in mind for these beginning stages of understanding ECG is that if something looks odd with that ST segment and it is elevated above that isoelectric line, You need, to the next step you need to call a physician, the practitioner, we need to find out what is best to do for this patient.