[music] Alright welcome everybody to todays lesson on Hemodynamics. This is going to be Part 1 in our series of lessons on hemodynamics principals and monitoring. My name is Eddie Watson and I am going to be your presenter for this series of lessons. And so let’s go ahead dive right in. So really, ultimately, you might be wondering what exactly is hemodynamics? And if we take the word and we break it down in to its components, its broken down in to “heme” which means blood, and the second part of it is “dynamis” which is movement. So essentially hemodynamics is the movement of blood. And the importance of hemodynamics is something that plays a vital role in how our body works.

Essentially that movement of blood is what’s going to determine at the tissue level how much perfusion we are getting in order to bring in oxygen and nutrients as well as taking away any excreted waste products. And ultimately the purpose of this lesson is to really go through and talk about all the different basic principals that are involved in hemodynamics. We’re going to talk about your basic anatomy of the heart and how the blood flows through the entire system. We’re going to talk about the different components that we look at and what makes up our hemodynamics. As well as we’re going to talk about some of the monitoring techniques that we use in order to have an idea of what our patients hemodynamics are. And finally we’re going to talk about the different ways in which we can optimize a patients hemodynamics in order to really maximize the blood flow throughout their body. With all that said, let’s go ahead and jump right in to our first section. And in this section, we’re going to talk about the basic anatomy of the heart and the vascular system.

The purpose of this, because I know all of you have had this in nursing school. You all have an understanding of the heart and how blood flows, but this is mainly going to be a review just to make sure that we are all speaking the same language. So to start off I just want to go through and label a few of the key parts that are really going to be important as we talk about things here. So the first is going to be our right atrium then down here we have our right ventricle. Then kind of a little hidden up over here we have our left atrium. And then finally down here we have our left ventricle. And as we know these are our four major chambers of the heart.

Our atrium is what pumps and feeds blood in to the ventricle and then the ventricle is what pumps in to the vasculature and moves it do the various parts of the body, depending on what side of the heart we are talking about. And as we all know the blood will go from our right atrium to our right ventricle, from our right ventricle it’ll go to our lungs. From there it returns back to our left atrium, which then feeds in to our left ventricle. And finally the left ventricle is the one the pumps the blood throughout the rest of the body.

One important thing to be aware of is that, as we know, as the blood passes to and from one chamber of the heart it passes through different heart valves. These various heart valves are going to be really import for you to know because if someone has certain insufficiencies or problems with these valves it’s going to cause problems with the way that the blood is flowing and will ultimately impact our hemodynamics.

So as we go through and talk about our valves, as we talked about the blood starts in the right atrium. And the first valve that we are going to pass through is, this valve right here, and this is going to be the tricuspid. From there the blood is going to be in the right ventricle and when the right ventricle contracts it’s going to pump the blood out through this valve here, which is going to be our pulmonic. From there the blood will make it’s trip and come back in to the left atrium at which point the blood will then pass from the left atrium to the left ventricle through what we call the mitral valve. Sometimes you may also hear this referred to as the bicuspid valve. And then finally, once the blood is in the left ventricle, when it contracts it will enter the aorta through the aortic valve.

So again if we think about the path the blood is going through we’re going to go from the right atrium through the tricuspid valve in to the right ventricle. From the right ventricle through the pulmonic valve it’s going to pass along and end up in the left atrium at which point we are going to pass through the mitral valve in to the left ventricle. And finally out the aortic valve. And I know that the location of these particular valves can be confusing for some nurses, especially starting out. It’s really important that you just remember that series that they go through; tricuspid, pulmonic, mitral, aortic.TPMA. Tricuspid, pulmonic, mitral, aortic. Now, I’m going to talk about a few of the different vessels that play an important role in this flow of blood. First its going to be the 2 largest veins that are responsible for returning the blood flow to the heart. These you are going to find over on the left here. We have, up at the top, our superior vena cava, which is going to be returning blood from the head and upper extremities. Then we have our inferior vena cava, which is essentially returning all of the blood from the rest of the body.

There is one last little section here. I’m going to put it right about here. This is our coronary sinus. Finally this is the last bit of blood that is being returned to the right atrium from all of the coronary vessels. So after that the blood is going to be ejected from the right side of the heart by the right ventricle out through the pulmonic valve and it’s going to enter in to the pulmonary artery. Now an important distinction is here we are calling this an artery because the blood is going away from the heart. But this is still deoxygenated blood because it is on its way to the lungs. This is why we have it drawn blue in this section here. From here the blood is going to go to the lungs, pick up oxygen, deliver carbon dioxide. From there it’s going to return back through a series of vessels we call the pulmonary veins.

And again these are veins because they are returning blood to the heart, but at this point they are oxygenated so this is why we have it red here. And also note that we do have 2 sets of these pulmonary arteries and pulmonary veins. We have ones that are going to and from the patients left lung here, and then we have ones that are going to and from the patients right lung over here. So now the blood is in the left side of the heart, it will be ejected from the left ventricle via the aortic valve and from there its going to pass in to the aorta. This is where the blood is going to begin it’s travel to all the different parts of the body. Just as one big review of the whole flow of blood. We have the blood coming from the superior vena cava, inferior vena cava, and the coronary sinus which are emptying in to the right atrium. It’s then going to pass from the right atrium, through the tricuspid valve, in to the right ventricle.

From there it’s going to be ejected out the pulmonic valve in to the pulmonary arteries which are going to travel to the left and right lungs. From there the blood, the oxygenated blood at this point, is going to return via the left and right pulmonary veins in to the left atrium. The blood is going to pass through the mitral valve in to the left ventricle. Finally the left ventricle is going to eject that blood through the aortic valve, in to the aorta and throughout the rest of the body. Alright so let’s look at things a little bit differently and have a little different picture of the hemodynamics and the blood flow through the body. So here I have things set up a little bit different. We have our right side of the heart over here, so obviously our right atrium and our right ventricle.

And then over on the other side we have the left side of our heart, so again we are going to have our left atrium and our left ventricle. Again just to map out the flow of blood, so we have our superior vena cava which is feeding in here, also our inferior vena cava which is feeding up here and then lastly our coronary sinus which is also feeding in to the right atrium. And all this blood is going to move across our tricuspid valve in to our right ventricle. From there the right ventricle is going to contract.

It’s going to eject our blood out through the pulmonic valve in to the pulmonary artery. From there it’s going to travel to the left and right lungs. This is now where obviously our blood is going to pick up oxygen and travel back and enter in to the left atrium. From there we are going to cross the mitral valve in to the left ventricle. Then the left ventricle is going to contract and push the blood out the aortic valve and in to the aorta.

Now once the blood is in the aorta, theres really only 3 main ways that it can go. The first is to go up to our brain and upper extremities. It can also go and travel down and around to the rest of the body. And the last route that the blood can take, is in diastole, the blood will actually travel back and fill in to our coronary arteries in order to perfuse our heart. So then again, if we continue to follow the path of blood, from the aorta we’re going to branch off in to our arteries, and then we are going to branch off in to our arterioles, and those are going to turn in to our capillaries and capillary beds at the end of the tissues. And then once they come out of the capillary beds we’re going to come out in to our veinuoles which will turn in to our veins, which will then work their way back either through the inferior vena cava or if we are coming from the brain or the upper extremities, were going to come back in through our superior vena cava.

And this really gives a conceptual map or picture of the flow of blood, which ultimately is our hemodynamics. And it is important that you understand this flow, where the blood is going at different points. Like I said, know the valves that you’re going through. Know what vessels you’re going in to. This will all play a role in determining our patients hemodynamics and later when we get to talking about optimizing those hemodynamics, if you have a good understanding of this flow, then things will be much easier for you. So at this point, this concludes this lesson on hemodynamics and covering the anatomy of the heart and the vasculature that plays a role.

In our next lesson we will talk about the actual delivery of oxygen which is the whole goal of hemodynamics..