Paroxysmal Supraventricular Tachycardia (Nursing)

00:01 Hi, welcome to our video series on the electrocardiogram.

00:05 In this one we're going to break down supraventricular tachycardia.

00:10 So there it is your old friend, the normal sinus rhythm strip.

00:15 Remember, you want to picture this in your mind as the standard, and then think about the strip that you're actually seeing and trying to interpret.

00:24 So let's quickly recap what an ECG strip looks like when a heart is beating in a normal sinus rhythm.

00:31 There's a P wave with a normal shape and duration preceding every QRS complex.

00:37 The P waves are positive and leads l and ll and biphasic in lead V1.

00:43 Also, the rhythm is regular, but remember that it can vary slightly during respirations.

00:49 Lastly, the rate is within normal range, which is between 60 and 100 beats a minute.

00:56 With that in mind, let's take a look at our next patient.

01:00 Now, it doesn't seem to be all that different.

01:02 The P waves look normal, and they proceed all the QRS complexes.

01:07 Also the rhythm seems to be regular.

01:09 The rate however, is not normal.

01:12 The heart is beating rhythmically, but faster than it should be, which means we could be dealing with a supraventricular tachycardia.

01:21 Let's take a closer look.

01:23 Supraventricular tachycardia refers to when the heart beats faster than its normal range, meaning faster than 100 beats per minute.

01:32 The electrical impulse originates anywhere above the ventricles, hence the name supra or above ventricular, meaning it can start in the SA node, the atria or the AV node.

01:45 SVT can also involve abnormal electrical pathways that bypass or corrupt the AV nodal checkpoint.

01:53 So as a result, the heart rate accelerates and the ventricles contract before they have properly refilled with blood.

02:01 So now we come to one of our question slides.

02:03 Hey, I put these in here intentionally to help you pause and recall and think about things that you're learning in the rest of the series.

02:13 So here's the question for you.

02:14 What is paroxysmal supraventricular tachycardia? Wow, I cannot believe I just got that all out in one take, because that is a really big word.

02:25 But what is it? Well take a look at the strip.

02:28 We start out there in beautiful normal sign is...

02:33 But what happens? It all speeds up.

02:37 Now the word supraventricular tachycardia, remember, it happens above the ventricle and tachycardia means very fast heart.

02:46 But paroxysmal means it comes and goes, it's not persistent.

02:53 So I think now you're really clear on why we call this PSVT.

02:59 It's just easier to say, than that big old set of words.

03:03 However, when you're just learning these concepts, looking at the words completely spelled out will help you remember what they mean.

03:12 So these are episodes meaning they start and stop a rapid heart rate, and they start in a part of the heart that's above the ventricles.

03:21 Now pause the video, you heard the definition I read to you, go back up and look at those big long words.

03:28 Paroxysmal, what does it mean? Supraventricular, what does that mean? Tachycardia, what does that mean? Spend some time jotting some notes down as you're doing that, that will help you remember that after you're done watching the video.

03:45 Now the R to R interval is shortened but it's still constant, consistent and regular.

03:50 What about the P waves? Yeah, because it's so fast, they're going to be hidden in there.

03:55 They're there but you're not going to be able to measure them.

03:59 They're what we call not discernible.

04:01 That just means you can't see them on the ECG strip, and you won't be able to measure them.

04:07 So think about your tachycardia.

04:10 Now there's different types.

04:11 Let's start at the very top.

04:13 Now don't get overwhelmed when you see all these things connected.

04:16 The best way to focus your mind is I would use a piece of paper to cover it or I would use my hand or you know that I love sticky notes.

04:26 You use whatever strategy works for you.

04:28 But we're gonna highlight things as we go through this.

04:31 So if it's tachycardia, that means it's fast.

04:36 So when I start with tachycardia, I asked myself a question, is it sinus rhythm? The answer to that question is yes or no.

04:46 Now if it's sinus rhythm, if the answer is yes, then it is sinus tachycardia.

04:52 Tada, we're done.

04:55 But now let's cover that back up and say, started tachycardia is it sinus rhythm? If the answer is no, then it's a tachyarrhythmia, that means it's fast, tachyarrhythmia, not normal sinus rhythm.

05:12 The next question you asked yourself is how wide is the QRS? So are you with me? We went back up to tachycardia.

05:20 We asked if it was sinus rhythm, we said no.

05:23 Now we're down to it's a tachyarrhythmia.

05:27 The next question is, how wide is the QRS? Now if the QRS is less than 0.12 then this is supraventricular tachycardia.

05:40 And it's either regular SVT or irregular SVT.

05:45 Okay, so this takes a little bit for you to walk through.

05:49 But if you slow down, pause the video after we walk through it together, and keep reviewing.

05:56 You can also use strips, lay this slide right next to your strip, ask yourself those questions.

06:02 And that's going to help you reinforce that learning.

06:04 So how do we diagnose sinus tachycardia? So show me where you would start? And how would you get to a diagnosis of sinus tachycardia? How would you get from a diagnosis of tachycardia to supraventricular tachycardia? Now what are the two types of supraventricular tachycardia? Regular and irregular.

06:33 Good, all right.

06:34 So you're learning to use this algorithm.

06:37 Now just following along with me won't guarantee you that you keep this information in your long term memory.

06:42 So if you understand it as we're going through it, do you know when the best time is to review this? Right after the video, correct.

06:51 You're going to get the biggest bang for your buck.

06:53 And honestly, who wants to study more than we have to? So reinforcing that information right after you looked at this video, and then again, revisiting it over time or after some space, you repeat what you study.

07:08 That's what spaced repetition is.

07:11 So we've gone from tachycardia to SVT.

07:13 We've gone from tachycardia to sinus tachycardia.

07:18 Now let's look at wide complex tachycardia.

07:22 That is referring to the QRS.

07:25 So start at the top, tachycardia.

07:28 You ask yourself, is it sinus rhythm? No, it is not.

07:31 So it's a tachyarrhythmia.

07:33 Now here is where we kept going straight down last time, but we're gonna take a turn here.

07:38 So how wide is the QRS? Well, in order for it to be SVT, the QRS has to be less than 0.12.

07:47 If the QRS is greater than 0.12, this is called wide complex tachycardia.

07:55 Now, this is not good.

07:56 This could be ventricular tachycardia or SVT with aberrancies.

08:03 Trust me, we don't want a patient to be in ventricular tachycardia.

08:08 That's a bigger deal than periods of SVT.

08:12 Now, let's look at the left side.

08:16 I didn't even start there, did I? No, because now I want to go back through and look at this all over again.

08:24 What is the first question on the left side of our graphic? It asks you are there P waves before each QRS? Is the P wave upright in lead ll? Okay, so remember, that's going to tell us what is going on in the atrium portion of your ECG strip.

08:45 So as long as you're able to follow through, you should be able to reinforce this learning, but it's going to take effort and some extra study on your part.

08:55 Okay, let's look at some examples of SVT with a regular rhythm.

09:01 Now, you may not start off with all of these rhythms if you're in a basic ECG course.

09:06 I just want you to have this information as you progress through nursing school and into practice so you've got it all in one place.

09:13 So we're talking about SVT (supraventricular tachycardia) with regular rhythms.

09:19 That means is real fast and it started somewhere above the ventricles.

09:24 Sinus tachycardia does qualify as an example of SVT.

09:29 Now look at that other one.

09:32 That is a weird one, isn't it? Hang on to that for later, we're not even going to delve into it for here.

09:39 But let's jump down to atrial flutter.

09:42 Yeah, you know that one with the sawtooth waves, that is also considered SVT.

09:49 Now you have ectopic atrial tachycardia and junctional tachycardia.

09:55 So we'll talk more about those rhythms in other video series.

09:59 But I just want you to be aware that you have a listing of all the examples of SVT in one place for your learning.

10:08 You look at the typical rate that you see in that, and you see the response to a valsalva maneuver or the medication adenosine.

10:17 So look at the different responses.

10:19 Now, we're not going to go into detail, but we wanted you to have this information as you continue your studies.

10:27 Atrial fib, look how this just messy.

10:30 Does that bother your OCD when you see something like that? It does get to me.

10:34 With atrial fibrillation, this is a rhythm that we have studied in this course.

10:39 And you see it there as an example of SVT.

10:43 Now, multifocal atrial tachycardia means it's boo, boo, boo, boo.

10:48 It's coming from multifocal or different areas of the atrium, you end up with this multifocal atrial tachycardia.

10:57 And that's why the P waves look different than what you see.

11:01 Atrial flutter with variable block.

11:04 Hey, we just talked about atrial flutter.

11:08 We did but look at what's different about this slide.

11:12 Notice that between some QRS complexes count the number of sawtooth and then look at others, they're together the QRS complexes are closer.

11:23 Ah, there's fewer sawtooth waves.

11:26 So this we would describe as atrial flutter, but it has a variable block, because sometimes you see differences 3 or 4 or 2 different types of flutter waves in between the QRS complexes.

11:41 Now, here's something unusual.

11:43 PSVT is one of the only arrhythmias or dysrhythmias which can occur in a normal heart.

11:50 Now, sometimes it'll stop spontaneously with vomiting.

11:53 Now, why would that be? That seems weird because we wouldn't really recommend that as a treatment, right? But if you stimulate the vagus nerve, that's going to slow down the heart rate and we'll stop PSVT.