Third Degree AV Block (Nursing)

00:01 Third degree AV block is called complete heart block.

00:05 Okay, this is a big deal.

00:08 This is like the atria and the ventricles are no longer communicating.

00:12 I will never forget the patient that we got to call, there's going to be a direct admit, from the doctor's office building that was connected to the hospital.

00:21 We expected the patient to be over in like less than 10 minutes.

00:24 We waited, we waited, we waited.

00:28 It took her hours to get there.

00:30 When she finally rolled into the unit, we thought, "Well, maybe she isn't in third degree heart block." We hooked up to the monitor.

00:36 For sure, she was in third degree heart block.

00:40 We said, "Ma'am, where have you been?" And she's like, "Well, I wanted to do some laundry and clean the house before I came into the hospital." We were like, it was crazy.

00:50 But you know, some people are we want to be in control and keep our lives in order.

00:55 But she legit was in 3rd-degree AV block.

00:59 Now let me explain to you what we knew as nurses and she didn't really see as a problem as the patient, otherwise she wouldn't have gone home and done laundry and housework before she came to us.

01:11 Now look at these P waves.

01:15 Okay, if you plot them across.

01:19 Boy, they will plot out equally that P is just happening with equal distances between P to P.

01:26 If you look at the QRS complexes go R to R to R to R.

01:32 Yeah, they're going fine, aren't they? But yet, there's not a P wave for every QRS.

01:40 They're completely not communicating.

01:45 So you may hear people say, the Ps march out meaning same distance, same distance, same distance, same distance.

01:51 Ours do the same thing.

01:53 Same distance, same distance, same distance, same distance, but they are not working together, they are like disconnected.

02:03 Because in 3rd-degree AV block, it's a complete failure of the AV node to conduct any impulses from the atria to the ventricles.

02:13 That's what makes this one different, and obviously, much more serious for your patient.

02:19 So we call it complete block.

02:22 3rd-degree is complete block because there is a total failure.

02:26 The AV node doesn't conduct any impulses from the atria to the ventricles, and this is what makes 3rd-degree block so serious.

02:36 Now, sometimes you may hear someone call it AV disassociation, meaning they are disconnected, not talking to each other.

02:43 This patient is at the highest risk for ventricular standstill, It can end up in sudden cardiac death.

02:50 So while she went home and got her house in order, she could have gone into sudden cardiac death at home, which would have been horrible.

03:00 Now I tell you that story, because she ended up being fine.

03:03 She went through treatment, and she went back home to clean her house again and to do her laundry.

03:08 But this is what could have happened.

03:11 But she's really good at talking her husband into taking her home first, and then bringing her back.

03:18 Now when we're looking at the blocks, sometimes they can look a little different.

03:21 So we wanted to show you this.

03:23 Key point: No association between the atria and ventricle.

03:27 But look, it can be on either side of the AV node.

03:31 So if it's on the distal side, then we can get a wide QRS complex.

03:36 But if it's on the proximal side, the QRS complex is more narrow, like you see in our illustration.

03:43 So we want to make sure you understand that there can be kind of two locations.

03:47 It can be on which two sides.

03:51 Right, we refer to that is distal side and proximal side.

03:57 Now look at the difference in the QRS complexes.

04:01 Which one tends to have a wider QRS? Beautiful, all right, you're really doing good tracking with us.

04:13 Wow, this is overwhelming.

04:15 All the possible causes of 3rd-degree AV block.

04:19 But in addition to teaching you the causes, we're going to teach you a strategy on the most effective way to study when you have 12 points to remember.

04:28 We're going to show you visually how to chunk information.

04:32 So we know causes of 3rd-degree AV block when we look at these, let's see if we can chunk them together.

04:38 First, pause the video and I want you to read through all 12 bullet points, then come back and restart the video.

04:52 Okay, now here's an example of how you could chunk information.

04:56 You see that first bullet point? Well, that's something that happened problem in the conduction system probably caused by coronary artery disease.

05:05 That's kind of a big segment, then down on the bottom to a congenital disorder and underlying structural heart disease.

05:14 we can chunk those together as direct issues with the heart muscle itself.

05:20 So we've shown you how to chunk these first ones together, what I want you to do is to look at the second side and look at how you would group those together.

05:32 Now, this is really tough for students.

05:34 But this is what helps you be successful in nursing school.

05:38 First of all, your expectation that you're going to remember, all 12 points won't happen.

05:44 You want to remember the most important points.

05:47 So see how we've got the first category, the first bullet point or we're saying a direct damage to the conduction system.

05:55 Is there anything on that right side that would also be direct damage to the to the conduction system? No, not really, in my mind.

06:04 But what about the structural damage from heart disease? Well, I could kind of group together things like post-cardiac surgery, and cardiomyopathies.

06:14 That would be one chunk.

06:16 Now see, is that visualized on the screen.

06:19 Cool. All right, we're starting to eliminate some of our points.

06:23 Now, a congenital disorder means I'm just born with something, I could also throw that into an underlying structural heart disease, meaning anything that kind of changes the actual heart itself.

06:37 So now, we've reduced our 12 points down to much fewer.

06:42 Now we've got a lot of other things in there like Lyme disease, rheumatologic disease, autoimmune disease, amyloidosis, sarcoidosis, muscular dystrophy.

06:51 I wouldn't be able to remember all those diseases, I would chunk those together as some diseases.

06:57 If you can remember those, that's great.

07:00 But know that this is how you're successful in nursing school, you don't just try to memorize everything, you chunk information together with understanding.

07:11 So now, you know, when you see a test question or you see a patient, hey, if they've had anything that could damage their conduction system, if they've had anything that could damage their structure of their heart, muscle, and then some various and assorted diseases, then I know that this patient is an increased risk for 3rd-degree AV block.

07:32 So there you go.

07:33 You can't memorize everything.

07:35 But if you chunk intentionally with understanding, when you see it in a test question, you'll know if there is damage to the heart, possible damage to the heart, be worried about 3rd-degree AV block.

07:48 Now when we treat AV block its pacing, because the patient has the significantly increased risk of ventricular standstill and sudden cardiac death.

07:59 So back to our chart.

08:01 Third degree is the complete failure of the impulse from the atrioventricular node to the ventricles.

08:08 So there's this AV disassociation and these weird escape rhythms.

08:12 They could be junctional or ventricular, but it's pretty bizarre looking.

08:17 How do we treat it? It's an internal pacemaker.

08:21 Now we've talked about our strategy and covering up the slides and then asking yourself questions.

08:25 Here's some examples.

08:27 So let's pretend you had all of these covered, you can just look away for that.

08:31 Which one is technically not a true block? Right.

08:37 1st-degree.

08:40 Which type of block is usually benign? Good.

08:46 2nd-degree type I.

08:50 What is another name for Wenckebach.

08:55 Good.

08:56 2nd-degree type I.

09:00 Thank you for watching this part of our video series.