Welcome to Dr. Warrick's podcast channel. Warrick is a practicing cardiologist and author with a passion for improving care by helping patients understand their heart health through education. Warrick believes educated patients get the best health care. Discover and understand the latest approaches and technology in heart care and how this might apply to you or someone you love. My name is Dr. Warrick Bishop and welcome to my podcast channel or videocast channel. Welcome also to the Healthy Heart Network. Today I'd like to talk a little bit about cardiac failure. Well, first of all, let me say that I think cardiac failure is a term that really seems quite, well, quite overwhelming if you ask me. We tell people they've got cardiac failure. Of course, you would imagine immediately they're thinking about an engine, a heart that's just not doing the job. I think it's quite a foreboding term to use for a heart that's not working. And my personal preference is that we should run, instead of heart failure clinics, we should run dicky ticker clinics or clinics for hearts that just aren't doing the job properly. So I think heart failure is a term that carries with it some fear, concern and uncertainty for patients. It is the term that we use in medicine and we recognise that it's a broad term and represents a degree of dysfunction from a minimal amount to really quite a lot. So we do use the term cardiac failure and I will use that term although... my preference in speaking with patients is to use different terminology because it's less confronting, at least in my opinion. Cardiac failure is a really important condition. We know that it affects over 38 million people worldwide. There is a lot of it out there. It affects 10% of people over 75 years of age. The condition, therefore, is broad spread. It has an impact on individuals. It has an impact on families. It has an impact on communities. And, of course, because of the cost of treatment and care, it has an impact on economies. So this is a really important subject to cover. It's a really important condition. Well, what is cardiac failure? How do people turn up with it? Well, it's a complicated condition. The heart is a pump that supplies all organs in the body. So if we think about it, if the heart's not working, it's quite possible that the circulation to all the other organs may be compromised in some way. One of the most common ways that people present with cardiac failure is shortness of breath. And this is most commonly during exercise. It can occur. at rest, and may even occur at night when asleep, waking people from their sleep. I'm going to talk about that a little bit more in another episode. It's also quite possible that cardiac failure may be associated with swelling. Swelling because of fluid retention. I'm going to talk about that in just a moment, because there is an interesting link where fluid retention fits in. to cardiac failure in the circulation, just not doing the job it should. Importantly though, because the heart supplies every organ in the body, we find that people with cardiac failure may represent features that include fatigue and lethargy, tiredness, inability to undertake their activities of daily living. They may be depressed. They may have renal impairment. Sometimes their liver function can stop working so well. Sometimes their legs and their muscles in their legs can be tired and easily fatigued. This is a complex condition that can affect not just the heart, but every organ and every function of the body. Well, what I'd like to do is take you back several million years to our ancestors and explain to you. a little bit about the reaction or the responses of the body to a heart that's not working properly. What I'd like to do is take you back several million years and ask you to imagine one of our ancestors who's just been bitten by a saber-toothed tiger. And our ancestor has got away, but they're bleeding and they've lost blood. Maybe a litre, maybe more. Not enough to die. but enough to really make a difference to the circulation. Well, here's the thing. Our evolution, millions of years ago, means that our bodies have mechanisms to assess how well the circulation is working. So our ancestors had evolved receptors, indicators within the body to constantly assess. the effect, the efficiency, the adequacy of the body's circulation. This included receptors in the heart, receptors in the major blood vessels of the body, the carotid, arteries and the aorta, and also receptors in the kidney. These receptors would constantly feed back, making... an assessment of the integrity of the circulation. If the circulation was inadequate through blood loss, say the tooth tiger example, then those receptors would sense that there was a lack of volume, a lack of blood in the circulation leading to that problem. And those receptors would trigger a number of actions. a number of responses, principally through the kidney, and I'm going to talk about this in a little bit more detail in another episode, but these receptors would trigger a response principally through the kidney to retain fluid, to rebuild up, replenish that circulation. Now, this was a fantastic thing to do if you've just been bitten by a saber-toothed tiger and you've lost a litre of fluid. Because what you wanted to do was put the body into a mode where it stored fluid to replenish that circulation, to get the blood pressure back up, to get blood flowing properly through all the organs. Makes perfect sense. Fast forward two million years with the same evolutionary tools on board, the same evolutionary receptors on board, the same evolutionary responses still intact. Now, no saber-toothed tigers in 2019 or 20. No saber-toothed tigers here today. But let's imagine that the heart, for whatever reason, stops working as well as it should. Let's imagine there's a degree of cardiac failure. That cardiac failure means the circulation is compromised. It means the circulation, the blood flowing to the organs within the body, is not what it should be. Well, guess what? Those receptors that have worked so well for us for millions of years start to realize there's a problem. The receptors in the heart, the receptors in the great blood vessels, and the receptors in the kidneys start to notice that there's just not enough blood volume, not enough blood pressure, not enough circulation. There's something wrong. And their response... which is what they've learned to do over millions of years is start to retain fluid. That fluid gets retained in the setting of cardiac failure and it is that fluid that can contribute to the swelling we see in cardiac failure and can contribute to the shortness of breath we see in cardiac failure as some of that fluid can actually end up collecting in the lungs. We're going to cover this in more detail, but it's a fascinating idea to think that The consequences of cardiac failure, the shortness of breath, the fluid retention, are really a consequence of a physiological response, a preservation response that worked particularly well in a different setting, working badly for us in this setting. This is a really interesting concept to get your head around. It's a really interesting idea to start to understand because it'll also give us some insight into how we're going to manage. cardiac failure in the longer term. So that's a little bit about what cardiac heart failure is. It's a complex mix of symptoms related to the heart not getting blood to all the organs of the body properly. There is a feedback, which is an evolutionary feedback, which is, if you like, misplaced to some degree in the setting of cardiac failure, but based on an evolutionary past where loss of circulatory pressure, loss of fluid within the system results in a response to retained fluid. What we're going to do over the next series is talk more about cardiac failure, how patients will present with signs and symptoms related to it, how we diagnose it and figure out what may be causing it, how we can be best placed to then deal with treating it, in regard to the body's response to it, and then what to expect in the longer term. There's a lot about heart failure, cardiac failure. It is a complex issue. It's one that I'm really looking forward to sharing more with you about. I'm going to wrap it up there. I hope you've got something from today's presentation. As always, if you have any queries or questions, please drop us a line. We'd love to hear from you. If you have any ideas for a podcast or a topic that you'd like us to share, please also let us know that. Until next time, I'd like to wish you the very best. I'd like to wish you good health. So goodbye for now. You have been listening to another podcast from Dr. Warrick. Visit his website at drWarrickbishop.com for the latest news on heart disease. If you love this podcast, feel free to leave us a review.
