PVCs vs ST Segment Depression on EKG

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Hi everybody, I'm a current nursing student and I hope this isn't a stupid question. How would you be able to tell the difference between a premature ventricular contraction and an ST segment depression. I know that PVCs can be multifocal and don't always occur at the area of the ST segment but how would you know if it does?

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Specializes in Emergency Department.
Hi everybody, I'm a current nursing student and I hope this isn't a stupid question. How would you be able to tell the difference between a premature ventricular contraction and an ST segment depression. I know that PVCs can be multifocal and don't always occur at the area of the ST segment but how would you know if it does?

I'm not going to tell you the answer but I will at least point you in the right direction to find the answer for yourself. You'll learn this stuff more concretely this way.

First off, these things are two completely separate things, aside from the fact that they can be seen on an EKG. ST segment deviations (elevation or depression) only refer to what happens to the ST segment. The ST segment is only part of the entire complex from the start of the P wave through the end of the T (or sometimes U) wave. A PVC a different appearing complex on an EKG that shows that the ventricles "fired" prematurely. It is possible for a PVC to have ST segment changes because the other complexes also have that same ST segment change.

Now that I have started things off for you, I suggest you review your EKG material because this stuff should all be explained in depth to you. If this still doesn't make sense to you, there are lots of resources around to help you understand this. Nurses that do EKGs or Paramedics (because they all do it) can also be a resource to help you understand this stuff.

Don't get me wrong, I'm not saying that this is a stupid question. To me, this shows that you're confused about something and you need help to figure this stuff out. That , to me, says that this is a great question for you, and I'm glad you're asking it! For a lot of us, it is a very basic thing but once upon a time, we didn't know this stuff... I hope this gets you started down the path of discovering the subtle world of the EKG.

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Now that I have started things off for you, I suggest you review your EKG material because this stuff should all be explained in depth to you.

You give school way too much credit. There is no "in depth" with this material in school.

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smf0903, you are very right. There is no absolutely no "in depth" in school.

To the OP, I suggest reading Dubin's "Rapid Interpretation of EKG's." You can get it very cheap on amazon and it is a fantastic resource.

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Specializes in Critical Care and ED.

The two things are really very different. A PVC is a premature ventricular beat that has a broad QRS complex. Often it just looks like a blip so you can't really measure it although you can look for patterns. For example:

• Bigeminy - every other beat is a PVC.

• Trigeminy - every third beat is a PVC.

• Quadrigeminy - every fourth beat is a PVC.

• Couplet - two consecutive PVCs.

• Triplet - three consecutive PVCs.

You usually only measure an ST segment on a properly formed PQRST segment in sinus rhythm. An ST depression is very specific and you would look for that in someone that has at least a small segment of sinus rhythm as you need to be able to gauge which leads the depression is showing up in. To find an ST depression look at a regular lead and see if the ST segment is below the baseline. It's an indication of a NSTEMI. A PVC doesn't necessarily indicate anything specific.

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Specializes in Ambulatory Care-Family Medicine.

Go to YouTube and look up EKG interpretations. There are several videos explaining how to interpret them and what each part means. Some go more in depth than others. I could never understand EKGs by just reading about it but once I saw a video explanation it all became more clear.

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Specializes in Stepdown . Telemetry.
smf0903, you are very right. There is no absolutely no "in depth" in school.

To the OP, I suggest reading Dubin's "Rapid Interpretation of EKG's." You can get it very cheap on amazon and it is a fantastic resource.

Best book ever!

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Thank you everyone for the replies, I really appreciate the help. EKGs are a little daunting but I feel like I just need more practice.

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You might find the following sites helpful. Although the latter two include 12 lead ECG information, the basic information concerning rhythm identification, wave analysis, etc. is appropriate.

Life in the Fastlane ECG Library

ECG Learning Center Characteristics of the Normal ECG

Analysis and Interpretation of the Electrocardiogram

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Specializes in OMFS, Dentistry.
smf0903, you are very right. There is no absolutely no "in depth" in school.

To the OP, I suggest reading Dubin's "Rapid Interpretation of EKG's." You can get it very cheap on amazon and it is a fantastic resource.

FANTASTIC book!!

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