Review of Electrical Conduction System of the Heart (Nursing)

by Prof. Lawes

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    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.

    About the Lecture

    The lecture Review of Electrical Conduction System of the Heart (Nursing) by Prof. Lawes is from the course Review: Anatomy and Physiology of the Cardiovascular System (Nursing).

    Included Quiz Questions

    1. The SA node, with the AV node and bundle of His as backups
    2. The AV node, with the SA node and bundle of His as backups
    3. The bundle of His, with the AV and SA nodes as backups
    4. The SA node, with no backup pacemaker nodes
    1. Electrical impulses are generated, but the muscles do not contract
    2. The ventricles contract spontaneously
    3. A lack of oxygen triggers spontaneous, irregular myocardial movement
    4. The AV node sends retrograde signals to the SA node
    1. Purkinje fibers
    2. The bundle of His
    3. The SA node
    4. The AV node

    Author of lecture Review of Electrical Conduction System of the Heart (Nursing)

     Prof. Lawes

    Prof. Lawes

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    Amazing style
    By Neuer N. on 17. September 2020 for Review of Electrical Conduction System of the Heart (Nursing)

    Please provide notes as well so that we revise our topic in brief as well