Review of Electrical Conduction System of the Heart (Nursing)

00:00 Hi.

00:01 I am so excited to share this session with you.

00:04 Because this is the reason I almost quit nursing as a student.

00:09 No, really.

00:10 They made me take a dysrhythmia course and I cried through the first three or four days of it.

00:16 because it just didn't make sense to me.

00:18 It looked like it was all over the place.

00:20 Then, the night before the exam, something clicked.

00:25 And that's what I want to share with you.

00:27 I finally realized, I could be a nurse, so can you.

00:31 It's really straightforward.

00:33 Once you understand the hearts electrical system, then dysrhythmias are going to make perfect sense to you.

00:40 So you're ready? I'm going to share with you what I wish I would have known as a student at the beginning of that course that I took.

00:48 So let's start with a fun question.

00:51 I know, I've got a weird sense of fun, but...

00:53 do you think your heart can beat without the brain? Well, it can, for a little while as long as it has oxygen.

01:03 You see the hardest autorhythmic See the headline up there? That means self rhythm.

01:09 Because the heart has its own pacemaker.

01:11 It can function independently of the brain as long as it has...

01:16 right.

01:17 Oxygen.

01:18 So the SA node is called the natural pacemaker.

01:21 And it also has the AV node in the bundle of His as back-up systems.

01:26 Now, they don't work as efficiently.

01:28 But the pacemaker of the heart, the main one is the...

01:32 right, SA node.

01:33 That's the natural pacemaker.

01:35 But the AV node and the bundle of His are back-up systems.

01:39 Now, thought about what is a heartbeat? It's just electrical impulses from the heart.

01:46 The hearts natural pacemaker or an implanted pacemaker causes the muscles to contract.

01:52 So in order to have a heartbeat, I have to have both electrical impulses and a response in the muscles.

02:00 P-E-A as Pulseless Electrical Activity.

02:03 That means boy, electricity is going through the heart, but it's not contracting.

02:07 It's why it's a pulseless.

02:09 But we're thinking about a heartbeat.

02:11 It's both the electrical impulses and the contraction of the muscle of the heart.

02:16 So feel your own pulse, pick a spot.

02:19 Easiest one, might be right here at your neck.

02:21 But when you feel the pulse, yeah, that's the part of the cardiac cycle where the ventricles are contracting.

02:31 So when you check your pulse, or your patient's pulse, that's what you're feeling the contraction of the ventricles.

02:41 Now, let's get down to the really important stuff, the hearts electrical system.

02:46 Its got a big slide there, but we have so many cool drawings for you in this.

02:50 This one is your basic startup one, but I'm going to break it down for you in a way that's going to make sense I promise.

02:56 So every heartbeat an electrical discharge passes.

03:00 through the hearts entire electrical system.

03:03 Don't even worry about memorizing all these right here.

03:06 I'm going to break it down for you.

03:07 but you can see overall it's going to start the SA node, AV node, move on down through the heart into the Purkinjie fibers.

03:15 Those are deep in the muscle of the heart.

03:18 So, let's get started.

03:20 I love the drawings that we have for you here.

03:24 If you just think of the heartbeat, right.

03:27 Boom, boom, those ventricles contracting.

03:29 I want you to think of it as a relay race.

03:32 So think of the electrical system as the heart, as a rewrote.

03:35 Is these got the runners handing off a baton to the next carrier.

03:40 So you got it? That's why there's a track on the left side, and you've got the heart on the right side.

03:46 Okay, let's break it down.

03:49 So we've know that we're in a relay race.

03:51 We're going to start with the SA node because that's the natural pacemaker of the heart.

03:56 The SA node carries electrical symbols down to the atrial ventricle node.

04:01 So think of it as starting in the SA node.

04:04 And moving toward the next relay point, which is the AV node.

04:08 So see where the red marker is there, and it's going to hand off to the AV node.

04:13 All right.

04:14 Now the AV node sends the signal to the bundle of His, watch the red marker as we move forward.

04:21 Bam.

04:21 Okay, so we've gone, SA node, AV node, bundle of His.

04:26 Next up in our relay race? The bundle branches carry the signal to the Purkinje fibers.

04:31 Now, you can just say Purkinje fibers, or you can say Purkinje fibers.

04:36 because I just think that's such a cool name.

04:39 And you've got the left and the right.

04:41 Now, these are deep in the heart of the muscle.

04:44 Pun intended. Sorry.

04:46 I said, "Heart of the heart muscle." but its deep within the tissue.

04:51 Now, they're going to carry it across the finish line because that's what Purkinje fibers do.

04:56 They are the ones that are the last stop to make those ventricles actually contract.

05:01 All right.

05:02 So look back now where you have the red mark.

05:04 See if you can trace it back from SA node, AV node, bundle of His, right and left, Purkinje fibers.

05:10 See, it's really not that difficult.

05:13 When we start talking about what the strip's look like, each one of those stops, makes it a little bit different waveform on a strip.

05:23 That's it.

05:23 That's dysrhythmias.

05:25 Now, we'll get a little pickier about how long they are in sizes.

05:28 But I promise you if you can follow us with that heartbeat relay race, you can do dysrhythmias.