Understanding Blood Pressure



This session will be a crash course in understanding Blood Pressure for medical professionals. Attendees will learn the basics of how BP is maintained, the importance of monitoring their patient's BP, risk factors associated with high BP, and how medical professionals can use the "Share the Pressure" project to help reduce instances of high BP and cardiovascular disease among black African & Afro-Caribbean groups. Keeping with the theme, the session will take place through the medal platform and use an image of a playground and dinner ladies to explain the concept of BP.
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This series is for Healthcare Professionals from GP practices in the South East London Integrated Care System.

Please only register if you work in the London Boroughs of Bexley, Bromley, Greenwich, Lewisham, Southwark or Lambeth.

If you are interested in running similar events in your area, please email for more information.

Learning objectives

Learning Objectives: 1. Learn what BP is and why it is important 2. Learn the two key mechanisms in influencing BP (cardiac output and peripheral resistance) 3. Gain an understanding of how the circulatory system works and why certain measures are used to maintain BP 4. Become aware of the difference in BP progression between younger generations and those currently living 5. Recognize the assistance of the afterload in shaping BP and how it can be used to manage hypertension.
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Computer generated transcript

The following transcript was generated automatically from the content and has not been checked or corrected manually.

Well, good evening everybody and welcome to one of our share the pressure sessions my name's makayla nuttall, I'm a cardiovascular nous, and for those of us who are joining live, welcome welcome for those of you who are watching goes on catch up well welcome to you guys too, um I'm going to share my slides now, and whilst I'm doing that, for those, i want to catch up, you won't be able to use the chat function, but for those guys that are here and I can see people joining goes, use that chat function and let me know whereabouts in Southeast london, you're from and what your role is, so um here come the slides and for anybody who's already attending or watching the slides will be made available of their fault they are available, they've already been uploaded into medal um and you can access them after this event. So this is share the pressure, and this is the first of a series of webinars that we'll be putting on um around helping people to understand the BP. More now share the pressure, is a project, It's um it's initiative that is a, is a collaboration between the Race equality Foundation, Smart health solutions younger lives, and BP, uk and it's for debt funded by the Burdette Trust for nursing, I couldn't get the words out and I've said nurses, it's for nursing um and I'm a nurse and share the pressure is actually too addressed. High BP amongst black african and africa ribhi in people using a shared decision making tool and tonight session is one of the webinars that we are having to try and help this project along and so this one is about understanding BP, trying to learn a little bit more about just what BP is really sort of going right back to the basics as it were now, we're using medal for our for our event um and it for anyone that's new to medal. This is fantastic, you're going to learn to love it especially if you're brand new to it. It's a perfect way of being able to keep everything for healthcare professionals all in one place, so we get to watch and share our sessions here. Your handouts have already been uploaded after you do the evaluation in here. Your your certificate will be made available so um yeah and this one this this this whole bit, we're doing through, share the pressure is, just everything will be kept through here, so when you do do your evaluation. If this little toggle here isn't put across that, says, catch up content make sure you do that that means that you can get the slides. I've already put up and um toggle this one and this allows you to get your certificate. If anything goes wrong, you contact the guys here at medal that absolutely brilliant. It's been devised by a cardiothoracic surgeon during lockdown, just really for um medical and healthcare professionals education, but onto the session, why are we doing this project in um in Southeast london in specific people and really it's because we know ethnicity is a really significant risk factor when it comes to cardiovascular disease and people are disproportionately affected according to our ethnicity, leading to higher rates of stroke and end stage renal failure now. We also know that um these people people are already less likely, particularly your men less likely to come forward for screening and routine health checks and also less likely to have BP controlled, so it's a really important initiative, I think we've had to try and address those inequalities that we know is sitting out there and you know there's no getting away from Covid 19 It has made things just so much worse for us and actually it wasn't great in the first place, was it so um yeah, so now what I'm going to do though is really talk to you about BP and how it's maintained, and what it's all about, so we're going to start with let's think about this understanding, BP a little bit more and molly's put hi hi molly in the chat, so why is it important when we know that hypertension affects one in four adults in England, it's the third biggest risk factor for premature death and disability, and the people from the most deprived areas the 30 times more likely to have high BP than those in the least deprived areas and it accounts for so much heart attacks and strokes. So we know that hypertension is a really big initiative at the moment across England and in fact, across the whole world because there was so so much we can do to help prevent, but what is BP and why do we need it well. This is an image of the circulatory system now we always see this is blue and red and we see the veins and the arteries and it moves blood around the body, and and we need a circulatory system that's how things get transported around our body. We have different systems as well that transport stuff, but this is our blood is a carrier of things that keeps oxygen nutrients flying around our body going to all the places it needs to go to and we have to have those arteries open. There needs to be a level of BP to keep those arteries open, so the blood can flow through and that BP so particularly when you're taking a BP and your feeling on the cuff, you're feeling it in those arteries and it's the blusher that's exerted on the inside of the arterial wall and here we've got some arteries here and now this is controlled by two main mechanisms, one is the cardiac output so that's when our heart contracts and that left ventricle pushes blood out around the body, that's one element of pushing blood into the circulatory system, and then we have our arterials which are really involved in that peripheral resistance that expanding and the contraction, allowing more volume or less volume to be there to to hold the BP in to hold the blood in, which helps to maintain our BP, so a really really clever system that we have there now. Um When I was a cardiac rehab nurse many, many years ago, I used to talk about BP, BP, and our arteries in the shape of these hose pipes, but actually are arterial system isn't like this at all okay. It's more like the blue hose pipes, it has the capacity to expand and contract down. You know and you'll know when it's a hot day and your baby dilating and you're all sort of widening out and then when you're cold, it all contracts back up again to try and keep warm thing well, it does the same to keep our BP up or try and lower it down okay, this expanding and contraction and really what we're going to look at is what helps to expand and contract those vessels and and why was it a system that was working so well that is now really not so good for us, so um oops let's have a look we have now obviously some of you are thinking oh okay like you're teaching me to suck eggs, but again, let's just go right back to basics, so we're all on the same page when the heart contracts and pushes blood out into the circulatory system that's pushing it uh that's doing sisterly, that's that contraction of the heart, it's pushing blood out that's the systolic BP that is the top number and then when the heart is relaxing and those left ventricles are filling again that those you've got two left ventricles that left ventricle is filling well that's that the diastolic that's diastole that's the bottom number that we hear when we take a BP and you can see, they're a perfect BP of 1 20/70 so there was something else though that is involved in blood pressure that we don't we don't always discuss enough, I think that's really sad, but we don't discuss enough and that's something called the afterload and the afterload is well imagine, your heart's got a contract and push that blood out into the circulatory system. How much pressure does it have to work against to actually push that blood out okay and that pressure that it has to work against that is called the afterload and it's important to know that because some of the things that we do affects the afterload, so the afterload, if it's made. If, if it's higher, then of course you can imagine the pressure that's going to put on the heart and some of the way that we manage hypertension is by helping to reduce the afterload as well riding. It quite back to this system to how our bodies were designed, and and actually you know our bodies weren't designed to last this long. We have been around on this earth for a very very long time, and a lot of systems in our bodies were designed to look after us when we were having different sorts of problems um so we were designed to last about 12 2030 years for the majority of our of our life. If you see here, we went back to the neolithic times, we lived to Iraq on average 20 to 30 In the Bronze age, we lived to be about 26 we didn't grow up old. You know for have enough problems to be able to get hypertension then with the advent of modern medicine and a lot of changes in the immunizations, vaccination, and antibiotics, um blood transfusions, a and e departments medicine. All of these things meant that we started to live longer and as we're starting to live longer and longer and you can see that you know, our laughed expects and see now is in the seventies. Um You know and that's our average one you know um that that now we're using our bodies for a lot longer, we're running into some more problems, the more that we've got these bodies around and partly because we're using them for much longer than they were designed to be used, but also because we're not really using them in the way they were designed to be used, So there are some systems in our bodies that is there to protect us and one of those systems is what maintains our blood pressure, so let's I'm just changing my slides, let's have a look, so we want to think about how is that BP maintained. Now, there's really complicated ways that that we have and one of the things I try and do is make those complicated things a little bit easier and so we have systems and I've put dinosaurs there because I want you to think about it was so long ago that these systems in our bodies were designed and I've put dinner ladies up there because um you've got dinner ladies in your body now. When I was younger to me, the dinner ladies were just those nice women who used to be um in the school playground, hanging around usually chat to their mates, I just thought and uh and just keeping an eye on things but what I didn't realize is actually they were doing something specific. There's dinner ladies, they were in the playground in high footfall areas where there might be a bit of trouble really keeping an eye out on things, watching what was going on, and if there was ever problem, they blow their whistle and something would happen okay, a teacher would come running or other dinner ladies would come over. We have dinner ladies in our bodies okay. We have things in our bodies that are just hanging around looking to see if everything's going okay, we're all right, and if you've got slight problems they will create you know, they'll blow a whistle, whatever that what that sort of whistle is and that system is fantastic. It was designed to look after us and a lot of the stuff around BP is really thinking about getting blood and oxygen to everywhere. We need to get it, so you know if we need to exercise, we need to run fast or put more oxygen to our set of legs for those muscles to be able to exercise but the most important organ we've got in our body um and as a cardiovascular unless you know, sometimes struggle to say this, but it's our brain and lots of systems in our body are designed to protect this brain um And you know because we can live without an arm, we can live without a leg. We can you know get rid of a kidney, you can chop your liver in half, you can have a heart transplant, but we can't live without a brain. We don't do a head transplant okay, so it's so important we have lots of systems and one of the systems we have, is making sure that our brains get enough blood and enough oxygen okay and that's this barrow results. I've said the magic where this baroreceptor cysts the baroreceptor system that sits, those, have a couple of different systems with our chemo receptors as well, but baroreceptor is what we're really going to focus on tonight, is really thinking about how that BP is maintained, and I'm going to you know try to make it as easy as peasy as possible, so the barrel receptors were there, so I want you to imagine hopefully you can see this. I've got little piglet here, so when we're lying flat, gravity doesn't do a lot to us then when we stand up, right, gravity kicks in and blood starts to pull down and there are systems in our bodies, the barrow receptors, the dinner ladies that will kick in momentarily and do things to push our BP up so they actually help us to be upright, okay, they allow us to do everything we need to do and keep us conscious and stops that gravity from pulling the blood down into our legs. Now. Of course, we get some people whose blood does pull down to their legs and their people with sort of orthostatic hypertension, so that's not what we're looking at today, we're looking at hypertension, so but we want to think about how those barrow receptors work, so let's have a look there, you are out one day playing and you're actually playing with your favorite dinosaur. This is how long ago this body system was designed, so you're out playing with your favorite dinosaur and oops that favorite dinosaur gets you by the leg and not only do they get you by the leg, they bite your leg off, so you've got your leg bitten off there's blood going everywhere now. We know as we start to lose blood. Our BP will start to come down because we've just got less volume in our circulatory system, so that BP will come down and that's when our baroreceptor start to notice, so they're hanging around parts of our bodies. You know in our aortic arch up in our carotids, top of our kidneys, just think of them as dinner ladies waiting to see as the blood pressure's gone up a bit, and that's not what we're looking at in this accidents were looking at the BP dropping down. This is our protective mechanism right so you're losing all this blood and the dinner ladies there and they're gonna blow their whistles and those whistles is which, which tickling the autonomic nervous system, so you're a, n s the thing that we the thing that our body does without us having to think about it and um and that you know it's all coming up here to do with our brain, which makes things work, so the dinner ladies blown their whistle and away it goes so one of the things it might do is say let's make that heart okay. We're going to do something with the heart. It's responding here and what we're going to do is let's increase that cardiac output, so now the way to increase cardiac output is either increase your stroke volume or your heart rate now, let's imagine, if you haven't if you've had your leg bitten off, then you can't increase your stroke volume, so you've got to increase your heart rate and that's the only formula that works to get more blood into the system more blood back into that circulatory system, so, and this was a classic sign that you know if anyone that works in surgery, then you looked for bleeding and I remember, I mean I never did surgery as well. It is a student nurse and a cardiothoracic nurse, but a sign of bleeding. You know you saw it that that that BP pot, dropping and the heart rate going up, but I don't think anybody fully. I don't think I I mean I knew that's what happened, but I didn't realize why it was all happening. All those you know 30 years ago or something so so that's one way now another way that those barrow receptors do is they tickle your adrenal medulla. Now these are a couple of little chaps that sit on the top of your kidneys and this is where we have the rent an angiotensin system, so those that adrenal medulla okay. They produce aldosterone and aldosterone helps to balance out the salt. It's looking really dark in here, I'm sorry, it's this time in the evening isn't it just feels like it's getting darker and darker. Um I thought I had enough lights but clearly not okay, so aldosterone you have all heard of aldosterone and it's a hormone that's in our body and it helps to balance out that salt and water level, so we've got a bit more salt we have to keep a bit more water in. If we lose the salt, we have less water being being able to be re absorbed, and that's all about controlling the volume of blood that's there and here we go, so this is our win in angiotensin system and we can see here where I've done this little little zigzag thing the elder steam in there is to either create more volume or make volume be less of blood that's there now the rennin angiotensin system. I'm going to start up here because it's an important one to remember that happens in in the context of hypertension and it's a fantastic system that's there, but sometimes it can be a little bit tricky to remember or to remember what the thing's do so. Let's start at the very beginning and let's start for angiotensinogen okay now that's produced in the liver and to me angiotensinogen well. It's just like the the old fashioned wimpy disney princesses, so the new modern disney princesses are totally kick it, that's I don't know why I think that's kick ass, but there's kick ass, disney princesses, whereas uh the old fashioned ones like snow white, it's just a bit wimpy, she's lovely but a bit wimpy sitting around waiting for prints charming to turn up that is angiotensin durgin okay, just floating around and. Then when when we have a problem, the kidneys kick in they produce renan and renan, is our prince's charming okay print's charming, comes along and boom together renan angiotensinogen boom. They make angiotensin one, an angiotensin one is full of potential, doesn't do anything but full of potential and it's only in the presence of an ace, so an angiotensin converting enzyme does it then create angiotensin two, which is full of axion, and that axion is that powerful vasoconstriction, but they also tickle the adrenal glands a little bit, which produces the aldosterone, which helps us to absorb more water because we're keeping that salted fantastic system and look the the barrel receptors those dinner ladies, they do directly affect this rennin angiotensin here, so they directly tickle those kidneys which the kidney will produce a bit more renan that renan print's charming coming along to meet angiotensinogen snow white together, they create angiotensin one, full of potential, gets converted by an angiotensin converting enzyme and ace, in the lungs to create an angiotensin two full of potential full of actions sorry, and that axion is a very powerful vasoconstriction, pushing that BP up okay, just creating less volume for that blood to circulate in fantastic system, and then of course they tickle down here that peripheral vascular resistance, which is keeping those little arterials nice and tight up, so a fantastic system that we have in our body absolutely perfect for when your leg gets bitten off by a dinosaur okay and when that happens, we you know this is what it's there, so this system was designed to look after us and now it's working against us and it's giving us so many problems so I'm really sorry, this looks blurry. It's great when I'm on the set of slides and then I turn them into a PdF and it goes all a little bit weird I'm sorry, but but that BP that raised BP that we have gives us so many problems and this is why we really want to get on top of BP. So for example as part of our work up, we looking at people's eyes, hypertensive retinopathy, and that's where that raised BP can actually cause damage to those little vessels we have in the inside our eyes and and we end up with hypertensive retinopathy and we see that as those little little fuzzy cotton wool areas, we do e. C. G. S, and that's looking for that thickened myocardium. We're looking at that thick and left ventricle where it's had to work hard to overcome the afterload okay, pushing that blood back out into the system. We'll keep an eye on the kidneys okay. We keep an eye on the kidneys because that BP well only is it bad for those big vessels. It's really bad for our tiny little vessels and our kidneys are precious creature's you know we've got two of them, each of them have got about 750,000 nephrons in and nephrons of those bits that you know, imagine the vessels getting that small down really causes damage and we know for people who are black african or african caribbean, much more problems with chronic kidney disease. Unfortunately, and then of course we end up with strokes, heart attacks, aneurysms, abdominal aneurysms, lots and lots of problems can happen as a result of that hypertension, so how do would the drugs work okay. My colleague joe, is going to do one of the sessions aren't really looking at how we manage and which tablets were used and the names of the tablets, but I sort of, give you a general overview of how the medication works because it sort of fits with that rennin angiotensin system, so this is taken from um so the your Clinical effectiveness Group for southeast london kessel have fantastic guidelines if you haven't looked at them already and I'll tell you where to go at the end to be able to come and look for them um. And I've just taken one bit of the kessel guidelines just to show you that for people who are hypertensive without type two diabetes, if you've got type two diabetes and that's a different matter but I wanted to see what are the tablets are and how do they work. So, if you're black african or african, caribbean, or if you're over 55 then we start you on a calcium channel blocker, So how does a calcium channel blocker work um well, let's go back to our system, So do you remember when I spoke about things that were powerful, vasoconstrictor well That's not what a calcium channel blocker does okay, doesn't do anything there what what the calcium channel blocker does is um literally reduces the amount of calcium, I'm missing a slide, we reduces the calcium and that moves between the cells now though sorry, I I giggled all my slides before, so I want you to imagine you've got your heart muscle and to be able to have your heart contract calcium has to go between the, in the cells and that's how each cell in our heart is able to contract to make the heart contract. You know, it's not like when we uh move our arms and those tendons and muscles and things okay. Heart cells contract in a different way and so if we block those calcium channels that are the calcium chart that the calcium is gonna flow slower through and less strong through those calcium channels. When the heart is still contracting, but instead of being sore, really strong heart contraction, it's going to be a little bit more relaxed, it's going to take some pressure off that myocardium when we take that pressure off that myocardium, then the heart muscle is gonna ask for lex, oxygen, so it just takes pressure off from all of it, but it also does the same in our arteries and our arterials, so remember our arterials can expand and contract up well. If we reduce the calcium passing through, If we slow that down a bit passing through the calcium channels, calcium channel blocker okay well, then what that do it would allow our arterial system to just relax a bit okay, so the relaxing a bit is a bit of a ok, there's just a bit more give in the system. It's a bit more which means when the heart's pushing blood out again, it hasn't got so much of a force to work over this just a bit more gift, that's there, that's how the calcium channel blocker works, so what about the next, in line, so the next in line is would be an ACE or an arb, however, so that's angiotensin receptor blocker or a um ACE inhibitor yet we can see here on the guidelines that actually first like well. The next step that we would do here is more is an ob because we'd be worried about other things. Um When we've when rather than an ACE inhibitor is first line here, so how does that work, so it's about you know doing these things of an evening. When you've done meetings all day, does make your brain go a little bit sort of all over the place, but uh but it's good to have you guys all here, we're here with me, so how does that work well, the ob, okay, the ob imagine go back to the beginning and you're tense energon, snow white meat, renan print's charming, makes angiotensin one, all of potential but not doing anything yet in the presence of an ACE, becomes angiotensin two, and that is a really powerful bas, oh constrictor, so an angiotensin receptor blocker means it's already been allowed to get to angiotensin two, but we block the receptors inside of our arterial walls, so it can't do the same level of vasoconstriction that it would do so that's where when OB works, whilst we're here, we'll just look at how an ACE work, so that works in a slightly different way, so, an ACE, back to angiotensinogen, snow white renan prints charming get together angiotensin one, full of potential oh we've just blocked this ace, this angiotensin converting enzyme blocker, an ACE inhibitor stops that means we're reducing the changing from potential into axion, and that axion is the powerful vasoconstrictor, so again got less powerful vasoconstriction all getting to lower our BP and then third line for the majority of people, will be a thiazide like diuretic and how does that work, will just be more water out okay. We just be more water out If you are getting to that point and you are going to move further on well, that's a different space and that's where joe will pick you up there, but I just wanted to go back to that when an angiotensin system to remind ourselves where it's at so share the pressure is this project and we're doing this little professionals and maybe community workers across southeast london um extra training and extra availability of of different resources that's there to compliment what is already happening and if you don't know what's happening, then go and get involved, mass is going on in your area um for different different initiatives, whether it's open lamberth, an amazing community staff or in bexley all the way all the way around, everyone's doing their own bits of really trying to get to grips with finding hypertension and managing it and this is what we're doing, we're helping to add to the sweet of things that is available to you, so this is one of the webinars that we've done and we've already done the welcome event where you've if anybody's watched that you'll have met well. Obviously, you have met me, you have met my colleague, joe, uh are good colleague david koro um on being able to be the team from Smart health solutions in being able to deliver this training aspect. Other sessions, we have coming up will also be well. They've been announced in case you haven't already been able to start watching them start signing up for them, so we've got one on using Heart age and that's the real critical bit of share the pressure that's a decision making tool, where just as it says it's heart age, it's getting people to understand the impact of their hypertension on the cardiovascular risk and we do that using heart age, we started to record some podcasts and two of them are available, so uh one is about understanding BP, so we reinforce this a little bit more, we don't go into quite the same detail, but we talk about why it's important um and we start to think about why it's important to think about heart age in the context of different communities and how it's uh really quite straightforward to um to understand as a concept. We're also building on our Resources Center, which is bringing in some quizzes soon, so they should be out the next week or two. We're gonna have quizzes for healthcare professionals and quizzes for patient's so we can really hoping that you'll be able to take on board a lot of what we're trying to get to and of course, we're always going back to what going on locally in your area and the guidelines from kessel are absolutely brilliant to be able to use and if you haven't looked at your local guidelines, there's one for each borough and um it goes into so much and I know that kessel have been quite active, so um yeah, that's pretty much me done. I would say so I want to just say that understanding BP whilst it's really important only one step on the journey, and I think if you can understand BP a bit more then we can communicate it better with patient's and therefore hopefully patient's can understand that more or people with high BP can understand it more to be able to improve future outcomes so that just is for me to say, thank, thank you for joining us tonight. I brought it in exactly on the half hour, I've got time for some questions if anybody has got any questions, but I don't feel that you have to because uh for anybody on catch up it's uh entity in the evening. Now when we're recording this, one again, we win our sessions live, and we're recording them in case anybody wants to be able to take part on catch up um the other bit for people who are on the session now, I'm going to click the feedback form and that means you can fill that in directly now, and um yeah, so I'll pause here for a second in case, anybody's got any questions but I am just going to natter on for a moment about some of the other stuff that's coming up so um oh shadow wants to know how, does all those static hypotension occur so what to do with hypertension, but it goes back to this bit here so when you're lying flat, gravity doesn't do anything, and when we stands up, then we don't have we have a bit too much give in the system, is it, where are blood starts to pull down here, and if our barrow receptors aren't kicking in and quite the same way or our our vessel, I don't have that same snapping back elasticity, which we know happens as we get older, and we also there's quite a there's quite a I want to say common, but it's not common condition, but it's becoming more frequently known about which is postural orthostatic tachycardia, um so pots for short, and that's exactly when we stand up, the BP goes down and blood pools in the down here in the legs and the tachycardia kicks in and that's happening more and more now, particularly through long Covid, so um and it's because our bodies just unable to respond in the way, it's supposed to respond to push that blood up. I hope that helps you there shanna and if you want to know more about pots, postural cardio syndrome pots uk have a wonderful website, um I'll just declare my interest, it's um I'm a trustee at potts uk, which is exactly the opposite of the rest of my cardiovascular world. Okay, that's so so people who are on the, who are joining on catch up, can't say that I'm chatting now to Shana, who said, thank you, or Sanha, who said, thank you for that, so, hopefully, that was a useful insight there, so I'm going to leave it here, I'm going to leave it here. Um Please do, I hope that was useful and please do get involved do your evaluations and for anybody is watching on captor. We do these sessions a bit chatty, join us on some more you're allowed to watch this things as many times as you want to. We'll be repeating this understanding. Hypertension. Understanding BP, we call this part one again next month and then they'll be on demand all the time and we'll also probably putting on a few more sessions too, so it just says good night and I wish you all well and good luck with hypertension in Southeast.