Pericardial Effusion and Cardiac Tamponade: Pulsus Paradoxus

00:01 Now, let’s go on here to just a little bit, make sure that were clear. And we are able to identify everything that’s according here. Now, what I wish to point out to you is – well, pressures.

00:13 You see LV, Left ventricular pressure. You see RV, right ventricular pressure.

00:18 What are we gonna do? What kind of maneuver are we going to then perform? And which we are going to see differences in pressure based on the pathology of pericardial effusion.

00:31 This is called pulsus paradoxus is where we are. Now, before we move on though you must understand the normal physiology, so that this makes further sense to you.

00:40 Otherwise, you’re going to completely, completely answer incorrectly.

00:44 You don’t want that.

00:45 So what’s happening? Upon inspiration, quickly walk me through this. What happens to the man of blood returning to the heart? Increase or decrease? Increase. Right? Remember, in inspiration the diaphragm contracts and moves downwards the thoracic portion decrease and becomes a vacuum. And there is more blood coming into the right side of the heart.

01:02 Granted? Great.

01:04 Remember, well upon inspiration, what then happens to S2? Upon inspiration, S2 gets further apart doesn’t it? A2 P2, what’s that called physiologic split.

01:15 Is that clear? So far so good.

01:15 Where is the more blood right now? You tell me, there is more blood where, on the right side.

01:20 And how you can confirm that’s physiologic splitting of S2? In addition, can you tell – let me ask you a question.

01:26 Upon inspiration, what may happen to your heart rate? Any idea? And this, you will probably have to memorize.

01:31 Upon inspiration your heart rate increases. So they might be a slight tachy. Alright a slight tachy, upon inspiration.

01:36 So there is a things that we’ve talk about, and you’ve known about. But just continue with this.

01:42 Upon inspiration there is more blood on the right side. and so therefore – I want you to think about that, Interventricular septum, the wall, it thus separating the right side from the left side.

01:52 Where is the more blood with inspiration? Where, where, where? Right side. Good.

01:58 What is going to do to the wall? What wall? Intraventricular septum for example.

02:02 Its going to push it to the left side, right? Its gonna push it to the left side. Why? Because there is more blood in your heart. Why? Because of inspiration. Why? Diaphragm moves downward. It's pulling more blood in to the heart.

02:14 Are you with me? Good.

02:17 So where is there less blood? Transiently upon inspiration. Where is there a less blood? Less blood on the left side, because there is less space.

02:27 That’s one reason as to why is there less blood on the left side. What quick me here? Where else may happen? You just put more blood into the right side upon inspiration, I’m going to bring in physio here, we have too.

02:41 Now, with inspiration, I need you to work with me and along with that compared to exercise.

02:47 An exercise, how much more blood is coming through the right side? Obviously more. Aren’t you increasing cardiac -- Close your eyes, you got this. Don’t memorize it.

02:55 You know, when you exercise obviously your gonna increase cardiac output, correct? The only way you can do that is to then a veno constrict. So far inspiration exercise more blood in the heart. Good.

03:07 Next. Right ventricular output. Increases because of more blood. Right? So now, you are increasing cardiac output from the right ventricle, Where are you going? Where are you going? Don’t go to the bathroom yet. Stay here.

03:20 You are gonna inject into the pulmonary artery from the right ventricle, clear? So there is more blood in the pulmonary artery. How do you think that the pulmonary capillaries are going to respond with more blood? Dilate or is it going to constrict? Remember this in physio an important, important point has to be and you can automatically apply this to exercise as well.

03:40 When there is more blood that has been kick out from the right ventricle, obviously, the pulmonary capillaries are going to dilate, has to think about exercise, don’t you need more oxygen? It makes no sense for you to constrict your pulmonary capillaries. That doesn’t happen.

03:55 So, so far, inspiration exercise, more blood in the heart, increase cardiac output form the right ventricle pulmonary artery.

04:01 We have vasodilation. So far so good? Okay.

04:03 So when we have pulmonary capillaries, which are vasodilated now, its inspiration, the point is, it doesn’t want to move forward because its pulling the blood in the pulmonary capillaries.

04:14 In addition, with inspiration, you are also moving the septum to the left side.

04:19 The combination of increase pulling pulmonary capillary and moving the wall to the left side therefore causes decrease with inspiration, decrease amounts of blood in your left side.

04:31 How can you confirm that? How can you confirm that? Your systolic blood pressure with inspiration normally may drop; drop 10 millimeters mercury by definition that is the limit, that is the full capacity at this point.

04:49 It should not drop great than 10 – I said drop, you should not drop great than 10 millimeters mercury.

04:55 But it will drop them because there is less amount of blood in the left side.

04:58 And you are measuring your blood pressure cuff in the brachial, right? So therefore, your blood pressure would drop now. What happens here with effusions? So now you’ve understood? Now you’ve understood the physiology. Let’s put in our effusion.

05:12 So now your effusion with pericardial cavity. That means that you have your heart which is more restricted And therefore, upon inspiration, you are gonna go through the same physiology.

05:25 But now at this point, upon inspiration, you see that, you see that arrow on top? The arrow on top is then dropping the systolic blood pressure, upon inspiration greater than 10 milliliters mercury.

05:40 We have a problem, this is called Pulsus Paradoxus. Are they just gonna come out in a stem of a question? or attending and just tell you, that’s pulsus paradoxus.

05:50 No, because that is actually not the most act who have name isn’t it? Its not at all a paradox.

05:56 It’s just an exaggeration of the normal, is that clear? Now, if it isn’t, I would like for you to go back and review the basic concepts that I just lay down the foundation for.

06:07 So that at any time you encountered the concept of pulsus paradoxus, you’re absolutely clear.

06:13 In pericardial effusion because of the restriction of the heart, upon inspiration, you will have a greater than 10 millimeters mercury drop of systolic blood pressure. And that is not normal. And that is what that arrow indicating.

06:27 Lets move on please.