Transcript for:
Heart Failure Overview Lesson

[Music] all right you guys welcome back to another video lesson from ICU advantage and this lesson is gonna be the first lesson in a series lessons in which we are gonna talk about heart failure and in particular in this lesson we're gonna go over all of the basics of what exactly heart failure is and so we're gonna break this down fully and really give you guys some good information on what exactly is happening with your patients when they do have heart failure but before we begin if this is your first time to this channel and you'd really be interested in more in-depth critical care education content such as this video then please do subscribe to our channel below make sure though you hit that notification bell that way you'll be notified as soon as our new lessons become available to you guys and I really do value your subscriptions the likes the comments that you guys leave they really go a long way in helping to support this channel here and for that I do want to thank you guys and my name is Eddie Watson and I'm gonna be presenting this lesson for you so like I said this is gonna be the first part in a series of lessons that we're doing covering heart failure it's really important that you guys have a good understanding of what's happening with your patients when they have heart failure because this is something that you guys are gonna see all the time and particularly a lot of the management of heart failure when it progresses to a certain point will only be possible in an ICU environment we will eventually get to that information in a later lesson and kind of talk about some of that management and treatment that we do but these are gonna be patients that you are going to be taking care of and needless to say as things progress to more advanced stages of heart failure your patients can end up pretty sick as a result when their heart is not really functioning like it should be and so to start out what we're gonna do is really give you guys a good overview of what exactly heart failure is and to do that I really want to start with a quick overview of what the responsibilities of our heart is to do and essentially the main job of our heart is to move blood throughout our body and so to do a quick recap of this process we have deoxygenated blood that's coming from our body and it's going to be entering in through these two veins into the right side of our heart over here that blood is going to move through out into the pulmonary arteries it's gonna be carried to the lungs in order to be oxygenated once that blood is oxygenated it's gonna move back in through the pulmonary veins into the left side of our heart it's gonna go through here and out through the aorta and ultimately on to the rest of the body I know it's a bit of a review but it's important to know that the right side of the heart is going to the lungs to oxygenate and the left side of the heart is distributing that blood to the rest of the body and obviously this is oxygenated blood at this point and so like I said the hearts job is to move this blood throughout our body throughout this system and as we're gonna talk about here in a bit heart failure is essentially when this is not happening the way it's supposed to the heart is not able to pump and get this blood throughout our system like it's supposed to really before we begin though I do want to go over some quick facts regarding heart failure and heart failure is one of the most common conditions that we find especially in our elderly population and in fact to really try this point home we estimate that probably more than five million people are living with heart failure and every year we're diagnosing another 550,000 people with heart failure and of all these people living with heart failure we see about two hundred and eighty-seven thousand people die each year so I mean this is just an astronomical amount of people that are ultimately dying as a result of this condition when we look at people's hospital stay this is the most common diagnosis and patients who are over 65 we do find equal rates between men and women although we do see in african-americans that they have about 1.5 times more likely of a chance of developing heart failure so like I said truly a big problem it's definitely something you guys are going to come across in your practice and it's important that you know what's going on so like I had mentioned earlier essentially heart failure and in general term is something that describes and paired cardiac function and this impaired function can happen on the left side the right side or in fact it can even happen in both chambers and this is something that we call by ventricular failure and so essentially what's going on is we have the heart and it's not able to meet the metabolic demands that's going on in the body and so if we think about it our body has our oxygen demands that it requires and these demands will go up or down depending on what we're doing activity or other things like that and normally what will happen is we'll get our heart to compensate so it's going to attempt to accommodate to these changes in demands that our body is requiring so in order to understand how our heart meets this change into man we have to think about the cardiac output equation and I actually have a really good video that I've done on this already which I'm gonna link to in the cards up above as well as down in the notes below but as a quick recap we know that our cardiac output is equal to our heart rate times our stroke volume so if we want to increase our cardiac output we have to increase either our heart rate or our stroke volume or possibly even both and so our heart will do that and attempt to compensate for this increase in demand but like we just talked about in heart failure the heart's not able to meet these demands and the reason for this is because in heart failure we have this decreased stroke volume that's just a byproduct of the failing heart and so as a result we don't have that ability to really increase our cardiac output in response to our body's needs and so in order to understand why this is we're going to talk a little bit about the pathophysiology of heart failure and this pathophysiology that we see resulting in heart failure in our patients is really the result of two primary dysfunctions although we can have a combination of both the first of these is what we call systolic heart failure and so as we know if we look at our normal heart here in the middle normally we have a very forceful and strong contraction that takes place and this is able to pump that blood throughout the body but what happens when we have systolic heart failure is the heart loses that ability to pump effectively it ends up with decreased strength and therefore it cannot eject enough blood with enough force to get it throughout our body effectively and the reason it's unable to do this is because we end up with weakened and smaller muscles with these enlarged chambers so if you take a look at our muscle wall here compared to the muscle wall on our healthy heart you can see that it's much thinner but at the same time this space and the chamber has expanded out so you end up with this big chamber with this weak heart and it's just not able to pump it's harder for the heart to be able to squeeze and eject that blood out while at the same time it also has more blood in there and so in fact in the next lesson in this series I'm gonna do a good breakdown on the difference between our systolic and diastolic heart failure but for now this is that the basics that I want you guys to know in order to understand some of the differences that are happening but essentially you guys can think of our problem with systolic heart failure as being a problem with contraction and so now the other type of dysfunction that you're going to see is something that we call diastolic heart failure and if you think about diastole is that time in which our heart is filling with blood in between each contraction and so you can really think of this as a problem with filling and essentially what that means is we end up with these larger heart muscles so as you can see if you compare this to not only our normal heart but our systolic heart failure you can see that these muscles are much bigger and since there's so much bigger they end up taking up more space and this causes the ventricles to decrease in size in order to accommodate for that larger heart muscle and so it's gonna happen as our heart's not gonna fill up with enough blood and so even if we have a strong contraction we're just really not going to be able to eject a lot of blood out of here again manifesting itself in a state of heart failure now like I just mentioned a little bit ago you can have heart failure that affects the left side of our heart or you can have heart failure that affects the right side of the heart or you can also have both sides of the heart that fail and this is what we call our biventricular now usually the heart failure will begin on the left and it then can progress to bright sided failure but this can't happen the other way around and you can start with right-sided failure and then that can progress to by ventricular failure and it's important to know that you can have both a systolic or a diastolic failure that's happening on either the left or the right side and you can even sometimes have a combination of both and really the symptoms that you're gonna see in your patient are gonna depend on what type of failure they have which side of the heart it is that's failing and those will manifest themselves in different symptoms again which we will talk about in a later lesson here so like I said this is a quick rundown to give you guys an overview of this pathophysiology and so that you understand what these two dysfunctions are that you're gonna see in your patient as well as how they're gonna manifest themselves but we will talk in much more detail about this in a little bit now next I do want to talk about some of our causes for heart failure and an important thing to know is this is usually a secondary condition and what I mean by that is it's typically going to be caused by some sort of other underlying disease process that has already impacted our patients cardiac output and again we will talk about these causes more in depth in these future lessons but the main takeaway I want you guys to know is that the heart failure is a manifestation of this damage that has already been done to our cardiac muscles these causes though they can be the result of either lifestyle choices or even underlying disease processes but over time ultimately these result in the death of cardiac muscle and by having this muscle die off the heart loses its ability to pump blood effectively so as these cells die the heart will become weaker and like we talked about when we lose that cardiac output the heart is going to attempt to compensate again either increasing our heart rate or increasing our stroke volume and in fact we are going to talk about this compensation that's going on here a little bit further in just a minute but in the early stages of heart failure for our patients these compensation mechanisms they're able to make up for this loss pumping ability and as a result you're not can't really see any symptoms or problems manifesting and so over time we're gonna see these cells they become overworked and as a result they're gonna need more oxygen but since we have a problem with our oxygen supply in heart failure they're not going to get the oxygen that they need and once again they begin to die off and so again this causes a decrease in our stroke volume and makes the heart failure worse and so you can really see that as we go through this this is a cyclical progression of this disease and so like I said I do want to talk further about this compensation process here and like we said our decreased cardiac output is what's going to lead us to this compensation mechanism and so when we look at this compensation there's really three types that we're going to see the first is going to be from our sympathetic nervous system and so by activating this system we're gonna see a couple things we're going to see an increase in our heart rate and we're gonna see an increase in our force of contraction and both of these are going to come as a result of activation of the beta receptors in our heart but what happens over time if we continue to activate this sympathetic response is we're going to end up with down regulation of these receptor sites and as a result this is going to lead to a decreased response and so what happens is if we continue to activate the sympathetic response is these beta receptor sites are gonna down regulate and they're gonna decrease in the number that there are and therefore when we go to activate them again there's not going to be as many and we're not going to see as much of a response now the second type of compensation that we're gonna see is by increasing our preload and so really we can think about this as increasing the volume of blood that's gonna be available in the ventricle before contraction this is what we call our preload by doing this we're gonna end up with an increase in the stretch and as a result we're gonna end up with a more forceful contraction so again if you think about the frank-starling law if we increase the filling of those ventricles they're gonna stretch out more and you're gonna end up with a more forceful contraction as a result and so really one of the best analogies for this is if we think about a rubber band so I'm sure we all know that if we stretch that rubber band out a little bit it's gonna snap back but then if we stretch that rubber band out even more it's gonna snap back even more forceful and this is essentially the basic principle behind the frank-starling law now the way our body is going to increase this volume of blood is going to be through the use of specific hormones and in particular we're going to be looking at our antidiuretic hormone or ADH as well as our aldosterone antidiuretic hormone I think is pretty self-explanatory but the aldosterone is really part of that renin-angiotensin-aldosterone pathway that we have in our body again I'm gonna link in a card up above as well as down in the notes really great less than they did on this talking about this system within the series on shock but the important thing to know is that both of these hormones are going to stimulate our body to retain fluid and by retaining this fluid we're gonna increase our blood volume but unfortunately for our patient with heart failure this increased contraction that we're gonna get is going to mean more oxygen demand therefore more blood that's needed and once again we're dealing with a patient who has decreased blood supply we're not able to meet the demand and so once again looking back at that cycle that we go through muscle cells are gonna die off and we're gonna further progress our state of heart failure now finally the third type of compensation mechanism that we're going to see is going to be what we call myocardial hypertrophy and essentially what this means is we're gonna see both a growth in the size as well as the amount of muscle cells within the heart so we're gonna increase the number of muscle cells that are there but we're also going to increase the size of the muscle cells that are still left and this is going to be an attempt to make up for those that have died off but once again back to that cycle of heart failure this then means that we're gonna need more oxygen therefore more blood supply but we're not able to get that so once again more cells are gonna die off and we're gonna continue in that cyclical progression in addition to this because we have more volume of muscle cell going on this can lead to the diastolic heart failure that we talked about in which we end up with the decreased chamber size and less room to fill and so really all these points that I keep going back to are going to take us to one last thing that I want to talk about and that's what we call decompensation and so what happens is we have this overuse of compensation mechanisms and this can lead to those negative results that we were just talking about and this is what we call d compensation so while these compensation mechanisms are intended to do our body good in the long run in our patient with heart failure we're actually gonna progress and worse in the symptoms of heart failure and in fact these compensation mechanisms by worsening the symptoms of heart failure they ultimately will lead to this state of decompensation and really these compensation mechanisms they also feed into each other and so as an example if we have this myocardial hypertrophy going on this could lead to an activation of our sympathetic nervous system which ultimately will continue to progress our decompensation but the body will attempt to compensate by let's say increasing the preload and so all of these work together and feed into each other and again can really contribute to that decompensation that we see in our patient alright so at this point I'm gonna stop this lesson we did cover quite a bit in this lesson it really gave you guys a good overview of what exactly is heart failure we did a quick overview of what the heart's job is and moving that blood around the body as well as we went over some of the stats on how often you guys are gonna see this we then moved on do a quick overview of the pathophysiology and the differences between our systolic and diastolic failure as well as talking about the fact that we can have left-sided right-sided or by ventricular failure and then concluded things here talking about some of the causes but really talking about that cycle of progression as our body begins to try to compensate ultimately leading to worsening of our heart failure and ultimately decompensation in our patient and so with all that said I do want to thank you guys for watching this lesson I really hope that you guys were able to get something out of this and have a little bit better understanding of what's going on in your patient that is having heart failure if you did like this video or you found it useful please do leave us a like down below as well as leave us a comment and tell us what you thought about it in the next lesson we're gonna go deeper into talking about our differences in this pathophysiology as we talk about the differences between our systolic and our diastolic heart failure in the meantime though head on over and check out our last lesson that we did in which we talked about the Glasgow Coma Scale as always I want to thank you guys for watching and we'll see you in the next lesson