Vagal nerve stimulation and heart rate variability with Exercise Physiologist Caelum Schild
July 20, 2025
Caelum Schild, a Senior Exercise Physiologist from Adelaide, Australia, specializes in POTS and related conditions. In this episode, he discusses tools such as transcutaneous vagal nerve stimulation (tVNS) and heart rate variability (HRV), sharing important research findings and his clinical experiences with these therapies.
Caelum's website: https://loftyhealth.com.au/
Episode Transcript
Jill Brook: [00:00:00] Hello, fellow POTS patients, and fabulous people who care about POTS patients. I'm Jill Brook, your horizontal host, and today we are interviewing Caelum Schild, who is senior exercise physiologist, and founder of Lofty Health and Wellness in Australia, and also a patient himself. With over 15 years of experience, Caelum specializes in managing complex invisible conditions such as POTS, ME/CFS, Ehlers-Danlos Syndrome, hypermobility, long COVID, fibromyalgia, you know, the whole batch. He comes recommended by the wonderful Australian POTS Foundation and works with them. And today we're gonna discuss some of the latest, greatest therapies Caelum is using to help get patients the best results. Caelum, thank you so much for joining us today.
Caelum Schild: Thank you so much, Jill. It's, it's great to be here. I am a really big fan of the, the POTScast and something that I listen to on a regular basis. So yeah, it's brilliant to be here. Thank you.[00:01:00]
Jill Brook: Well, it's great to have you and you know, it's fun that we were just discussing that your wife is your partner and she's an occupational therapist who also works with the same population, so I am guessing that means that you guys are probably always discussing both sides, so you probably have, you know, expertise in the occupational therapy side of things too.
Caelum Schild: Yeah, a little bit. Yes. Yeah. So, um, I, I typically sort of focus mostly on some of the non-pharmacological, um, strategies for POTS. And obviously exercise is a part of that, but yeah, there is a little bit of crossover with, with that in, in terms of aids to be able to help people as well. So it is something that, yeah, we often do talk about strategies for, for other patients, but also I guess she's been there right throughout my own journey as well as, as amazing support.
And I must admit, I've, I've sort of been someone who's kind of roped her into to working with this population group as well. And I guess, you know, some, [00:02:00] some therapists, I guess you are just sort of, uh, sort of made for, for working with this population group. So her empathy and understanding and all of those sorts of things is, is quite incredible and something that I've been fortunate enough to kind of experience firsthand myself, but then in a professional sense, yeah, it's something that, yeah, she's able to provide quite, quite significantly too.
Jill Brook: Yeah. Yeah. I always think it's fun how like, marrital osmosis makes you pretty knowledgeable at whatever your spouse is talking about all the time, so that's cool. But, okay, so let's, let's get to know more about you. Can you tell us more about your background and how you became an expert in Dysautonomia and all of these invisible illnesses and how you came to do what you're doing now?
Caelum Schild: Yeah, so I guess you've provided a really good summary before, um, in terms of my background, which is really, really nice to hear from a professional sense, and, and I'm really lucky [00:03:00] here, I guess, um, locally in Adelaide, in South Australia. We've got a POTS clinic that's set up specifically for, for treating POTS patients.
And it's something that I'm connected in with, with that clinic as well. So, and together with the clinic, we've obviously got the research group from Adelaide, and so I sort of touched base there too sort of professionally, which is, which is great in the small amount of, I guess, spare time that I have too.
But I guess like, particularly in Australia, like so many of of our therapists over here that work with POTS, my own personal journey, I guess is something that led me to, to working with this population group. So, I guess from quite a young age, so adolescence, I was always one of those kids that, um, would get quite dizzy when standing up too fast or particularly if standing still as well.
So, I guess it was something for me that I've always sort of recognized and I do [00:04:00] have quite a lot of the hypermobile traits, so I suspect it's probably linked to that. And so my first job, I remember like at the local supermarket where I would be quite dizzy getting up from sort of squatting down stacking a shelf and you'd get what we, I guess know as presyncope.
And yeah, quite, quite dizzy off the back of that. And and for me, I used to play Australian Rules Football, um, was my sport. And I guess the Australian listeners would understand, and I guess in, in the US it's there's some similarities with, with NFL football minus the helmets. And so concussions are quite common,
which I've had several of. And I, I wonder how much those concussions maybe play a role. But my first POTSy episode was during uni. So I used to park my car quite away from uni and walk in, and I was [00:05:00] walking one day and then stopped walking at the traffic light. And because I was standing stationary,
I didn't really know what it was at that time, but I had a, a very presyncope episode. So, um, yeah, essentially everything kind of blacked over and I started to have that real hyper adrenergic response. And the kind of catch 22 was with that, was that I was actually opposite our, our main hospital in Adelaide at the time, and I presented to ED and they kept obs and and administered a couple of bags of fluid and fluid's
amazing for POTS, isn't it? And so I didn't really sort of consider that too much I guess for another couple of years until we had quite a traumatic event in our family. So, my sister passed away when I was 21, and I guess the trauma associated with that was something that impacted my nervous [00:06:00] system quite substantially.
But it never really like, it, it, it never really, sort of changed too much, I guess. Like I was left with that, even with some of the emotional processing that comes with such a traumatic event, it was something that continued to have quite an impact on my, my body physically after that. And I guess that's when I really started to notice those really common symptoms of, of like headaches and brain fog,
and fatigue, were sort of my really big, symptoms at that time. And I remember keeping like a headache journal and it was how bad that headache was for six months so I could give it to the doctor. And there were rarely days without one. And finally got that diagnosis, which was initially sort of autonomic dysfunction and, and later on
POTS and it sort of required a lot of adjustments day to day. So I had to give up my, my AFL footy and, and took up mountain bike riding, which is something that I still do, and something that I can do. I still [00:07:00] have to manage what I do with that, but it's something from a movement perspective that I can, can do.
Um, and for me, diet has a massive impact. So I had to really overhaul the dietary component, which I know that you know very well. And, um, and I guess then the next stage for me is I didn't realize how well I was pacing until we had our children. So we're very blessed to have a couple of young kids.
And that next sort of flare or big change in my, my POTS was sort of after our second child was born, I didn't realize how much I needed to pace. And, and that's when I, I guess, transitioned from my typical exercise physiology work in the background for sort of the 10 years prior to that, to just working with, with POTS and co.
So I was doing a bit of both. So seeing people with POTS and co and in Australia we'll see people for [00:08:00] exercise physiology for things like diabetes or heart disease. But at that time I connected in with the, the POTS clinic here and, I was really fortunate to be able to just work in that, in that space, which I love.
And, and we've been doing it for three years now, um, or bit over three years, which is amazing.
Jill Brook: Wow. And that's fantastic that they have, you know, somebody who's really been there and understands that they can send all of their POTS patients to. That's phenomenal. So, I'm, I'm curious, so given that you've worked with sort of patients who have things like diabetes and cardiovascular disease, how are POTS and invisible illness patients different?
Like what kinds of challenges and goals do you help patients with now that you have this population?
Caelum Schild: Yeah, I guess with, with a typical population, like particularly as as an exercise physiology background, exercise legitimately is, and there's [00:09:00] brilliant research to, to suggest that exercise, and the more we do, the better, essentially helps to regulate that. And I think we all know, and I'm certainly personally familiar and I know you are as well, where there's our perfect amount of movement. That may not be structured exercise for some people.
But there's our perfect amount of movement and then it's a really fine line between not enough and too much. And that's where, I guess I love that investigative work behind that and helping people to find what that baseline is for them. And and so typically, sort of now I, I work with a really broad range of patients.
So, um, often they're between sort of bed housebound all the way through to elite athletes with, with POTS. So, the way that we manage that is very, very different in terms of what we do for, from a non-pharmacological standpoint, for, for their POTS and exercise.[00:10:00]
Jill Brook: So, so just for the people out there who are being still told in 2025 that their POTS is at least partially due to their own deconditioning, you are saying that you have elite athletes that still
have POTS. So for them, obviously deconditioning could not be any part of that.
Caelum Schild: Absolutely. Yeah. Yeah. And I guess where we do see, where, where the, the deconditioning component can come in is that secondary deconditioning. So something that I do talk about with people where, hey, if we stop doing that thing that we've normally done. Our body's not gonna be accustomed to doing that straight away again.
So there's gonna be that lack of ability to, to slot straight back into that thing. But yeah, it's, it's completely autonomic, like it's the autonomic nervous system or that automatic part of the body that responds to the movement. And then recovery from the movement or the demand on the person that [00:11:00] is gonna have much more of an influence than purely, I guess, how their heart functions, which is only an incredibly small part. So if we, if we look at it like there might be still maybe a percent or something like that of all the POTS patients that might legitimately present with that deconditioning, but it's so tiny, and particularly for the average POTS patient, if there is one, it's just not, not a consideration.
Jill Brook: So, you know, this is making me think of a question that I have had for myself for a long time, and I'm gonna assume enough other POTS patients have it that I'm gonna take the liberty to ask you. I find that doing the same exercise at 8:00 AM is so much harder than doing it at 3:00 PM. Is that a thing in POTS?
Caelum Schild: Absolutely. Yeah. And I'd say it's not there's, there's no typical, so we do see some people where they do cope with morning movement better. And there's a variety of reasons for that, I [00:12:00] think. But I guess from my insights, it can come down to that ability for us to build blood volume as we start the day.
Perhaps begin to use up some of that adrenaline, push some blood around the body. Um, I guess the, the physiology that's required for us to be sleeping looks and, and where our body has to push blood and what our autonomic nervous system does, is very different to what it looks like once we've been maybe up and moving a little bit, even if that is just from room to room for some people.
And then also we've got that, like that diurnal component of POTS of the fact that typically a typical presentation with things like orthostatic intolerance will look a little bit different in the afternoon compared to the morning. So basically it'll be a little bit more POTSy in the morning than the afternoon.
Jill Brook: Okay. Okay. Good to know. So you said something really intriguing a minute ago, and I was wondering if we could dig a [00:13:00] little deeper. You said a big thing that you do for patients is help them find that perfect amount of exercise for them where it's enough but not too much. Can you talk more about how you help people do that?
Caelum Schild: Yeah, so I guess first of all, with, with patients, it's about trying to sort of learn their goals for, for movement. So typical sort of goal for, for most of our POTSies will be just to improve that daily function and improve their POTS and, and EDS management as well. But something that we, that I often typically will use is technology that we have available now.
So things like heart rate monitoring devices and heart rate variability that can, I guess bring some of those invisible aspects that we have with POTS and autonomic dysfunction to make them a little bit more quantifiable or objective in nature. Um, and so it's something I guess, that I [00:14:00] typically will help people sort of to learn,
okay, where's that intersection between how our body's reacting, and then also what the data is saying for that particular day to help guide us. And then off the back of that, I'll tend to help people with sort of that full range of non-pharmacological strategies. So, that can look at things like salt and fluid.
We might touch briefly on diet, but we've got great dieticians and nutritionists here that are POTS specialists and aware, so I tend to tend to sort of refer those on. Vagus nerve stimulation as well. So things like breath work and, and similar and, and hopefully we can touch on some of the other vagus nerve stimulation strategies.
Jill Brook: Yeah. Yeah.
Caelum Schild: And then even trialing things like compression boots as well. So I know you've mentioned before on the podcast about, compression boots and how they may play a role for some people.
Jill Brook: And when you say compression boots, you mean the ones [00:15:00] that are inflatable and and like squeeze blood up your leg?
Caelum Schild: That's the one. Yeah. Yeah. And obviously I have quite a short short lasting effect, but it's something again that requires little effort to implement. So if someone can't, I guess, do the movement to be able to squish that blood mechanically back, or if there's a medication like Midodrin here in Australia which is a common medication prescribed to push some of that venous blood back up towards our heart and brain.
If they don't get along with that or they're already at a maximum dose, how could we look at other strategies to perhaps help with pushing that blood back for recovery and, and day-to-day function.
Jill Brook: Yeah, for sure. So, so, okay, so you have all kinds of cool technology that you use. Let's, let's talk about some of it. Where do you wanna start? You mentioned heart rate variability. We wanna cover
[00:16:00] that. Um, vagus nerve stimulation, we wanna cover that. And anything else you wanna talk about, but but yeah, where should we start?
Caelum Schild: Yeah, well, like maybe the vagus nerve stimulation side of things, if, if you like, 'cause that's something that I guess is really, it's really interesting the, the vagus nerve side of things. And I, I guess this is where sometimes it can be helpful having POTS yourself to be able to try things yourself before you, maybe before the evidence is there.
And also to kind of gain an understanding of what sort of impacts it might have on your body. And so for, for me, my first experience with particularly the, the transcutaneous Vagus nerve stimulation, um, which is sort of something relatively new in this space, was on myself because we didn't have the research there a couple of years ago.
And particularly on POTS, there wasn't the research and so it was something that, I [00:17:00] guess as an emerging strategy, I was like, I'll give this a go myself and see what sort of use it has. And yeah, from there it sort of developed into a tool that we can control with people. Would it be useful to maybe touch on what the vagus nerve does for, for people in this context?
Jill Brook: Give us, give us the whole, the whole spiel.
Caelum Schild: Yeah. Yeah. So, the vagus nerve is a refresher 'cause I know you've talked about it on the podcast before with people, but the vagus nerve essentially has quite a substantial amount of parasympathetic fibers, so about 75%, I guess they, they sort of indicate, and because of that it's got a quite a large role in
promoting more of that rest digest sort of parasympathetic nervous system state in our body. And the way that I often sort of describe this with people is if you can imagine a car where we've got an accelerator and a brake pedal [00:18:00] and in a car, our foot is usually on one or the other, but in our body we need really good balance between that break and accelerator and
one of the common things with POTS, I guess, is that our foot is a little less on the brake than it needs to be and a little bit more on the accelerator. And so we get a lot more of that sympathetic flight nervous system activity starting to shine through with, with a lot of people with POTS. And,
I guess that's where the vagus nerve stimulation comes in is it helps us to kind of dab that brake pedal a little bit more, to get a bit more balance between the two and more optimal sort of function of that vagus nerve. And other types of vagus nerve stimulation typically are, are things like breath work that we kind of touched on before.
There's some broader research around things like laughter and humming and gargling and those [00:19:00] sorts of things as well.
Jill Brook: Can I ask a question about that?
So I have tried all of those things 'cause I definitely am a person where like, as you make this metaphor about having the foot on the gas too much and not enough on the brake, I'm laughing because in my head this metaphor ends in, you know, crashes. But, but, so I've tried a lot of those things and I've never felt a difference.
Like, do people feel it when it's working? Like, do you know, and like, I've tried a couple of the different devices and I've tried the gargling and the laughing and I don't know if I haven't done it enough or if I haven't found the right device, or if you just, it's something that works without you necessarily feeling anything.
Caelum Schild: Yeah. And so for some people, what we are learning with some of the basic research that they've done on TVNS especially is that for some people it actually, they won't notice a difference. But for the next person they have a profound sort of or they can notice a profound difference [00:20:00] or profound impact on their function.
And for some people that can be immediate, where they notice improved blood flow to the brain. So they feel like they've got clearer thinking. They feel like they've got more of a calm, nervous system. They can feel like they've got more energy in some instances as well. But in others, they, and I guess in that research that we'll touch on in a moment if you want to cover that, is even with the TVNS, they found that as a, as a group,
they didn't notice a, a, an impact on their symptoms as a whole. But when we actually went and discussed with the researchers around it, which our team in Adelaide was fortunately enough or fortunate enough to be able to discuss with them, they found some really profound impact in some people, but in others, even though their standing tests improved and their
heart rate variability improved and [00:21:00] their inflammatory markers improved, they didn't actually notice any difference.
Jill Brook: Wow, that's so interesting.
Caelum Schild: Yeah. So I wonder if that might be a similar thing in, in your instance as well. And that's where, I guess what I still encourage for people is like, we can try all of these different vagus nerve strategies and there's a set amount that we can try and it's not anything that you've done wrong necessarily if you haven't noticed a difference.
It's just your nervous system in terms of how it responds.
Jill Brook: So, um, for how long do you typically have people try it before they give up? Like a week or six months, or?
Caelum Schild: Yeah. So, um, oftentimes, are you talking about the vagus nerve that some of those other strategies that you've tried or the, the, the TVNS.
Jill Brook: Well, whatever, whatever you tell people to do.
Caelum Schild: Yeah. Yeah. So, um, I guess for all of those different strategies, I mean, if we're not starting to notice a difference within a couple of weeks, like generally for most [00:22:00] people, it's enough time to, I guess, ride out those normal ups and downs that we see in POTS. And so if our body is in more of a parasympathetic state on one day or a more of a sympathetic state on another day,
there is potential that our body could respond a bit differently to those, and so it lets us have enough data points to be able to give it a really good go to see what sort of impact it's having on our body.
Some of the other vagus nerve strategies that we talked about before, we've also, in recent times, been using things like TVNS, so that's called transcutaneous auricular, which is ear based, um, vagus nerve stimulation.
And for short it will be called either TVNS or T-A-V-N-S is some of the acronyms. Um, and I [00:23:00] guess where I see it can be quite appealing for people is for people who don't have the energy to be able to try some of those other strategies that we talked about, 'cause even breath work requires some energy, um, for us to do.
And so for people who are quite bedbound and unable to maybe try some of those active strategies, it can be useful. And essentially what it is, is a low grade electrical stimulation of the vagus nerve through the tragus of the ear. And so we clip a little clip, a special clip onto the ear, and that electrical stimulation is at a level that's a bit less than the sensation threshold.
So we actually don't need to feel it to be effective. And it's quite similar, the machine that they use to a TENS machine that some people might have heard of for pain. Um, [00:24:00] and some people including myself will use a TENS machine, but I guess it's really, really critical. So if anyone goes down that pathway, you just don't have to make double sure that
it's actually set up appropriately because you don't want it to cause complications because it's not set up appropriately. And the reason that the tragus is ideal is that it's quite close to where the vagus nerve passes through. And so I guess that is a whole giving you sort of a summary of what the TVNS
does. The, the study that they conducted and published on by Stavrakis and colleagues in 2024, where they took 26 people and they randomized them. So they got half the group to hook it onto the tragus and then the other half to hook it onto the ear lobe.
Jill Brook: Okay, so two different parts of the ear. So they thought they were getting [00:25:00] the transcutaneous vagal nerve stimulation, but they weren't, they were just having a clip on their ear that was vibrating a little.
Caelum Schild: Yeah. Yeah. Yep. So really interesting. So I guess from, from a study design perspective, it was great 'cause, um, we're going to see quite, quite meaningful
results. And it was only small, so like a lot of POTS, POTS, papers, it was only 26 participants. But they did that vagus nerve stimulation for an hour a day
in that particular study, which clinically use of vagus nerve, uh, stimulation, doesn't need to be that long, is, is what we find for, for individuals. And the frequency that they had, their stimulator set up was 20 hertz and 200 microseconds. And they followed them for a couple of months. And what they found was, like I sort of touched on [00:26:00] before improved orthostatic tolerance with a standing test.
They saw reduced autoantibodies as well with in terms of their blood markers and inflammatory cytokines, um, and increased heart rate variability. But as I mentioned before, unfortunately as a, as a group, they didn't all see that impact in terms of function.
Jill Brook: Wow. But you're making me think that for those of us who have a vagal nerve stimulator sitting around anyway, we should probably use it. For, um, my next question is gonna be how many minutes a day?
Because if it, if it reduces, especially for those of us who know we have some autoimmunity, 'cause if it reduces autoantibodies and helps your your other markers, cytokines, you said, so inflammation, that sounds like that's gonna pay off some way somehow, even if you're not feeling it.
Caelum Schild: Yeah. And potentially, and that's the thing, I guess, and that's where we are really [00:27:00] fortunate to have our local research group that I contribute to, um, Dr. Celine who had a conversation with, with the researchers about, well, what did we notice, and there were some people that were like, give this thing to me.
It's, it's amazing. It's, it is changed my life so much. And then others in that same intervention group that just didn't notice anything. And and I guess that's where every individual is going to then potentially determine, well, is it a good use of my time having this thing clipped onto my ear if I don't feel anything?
But it may help some of that, those autoimmune markers. And, and I guess that's what our clinical experience has been as well. So, um, I've, I've used it with, oh, probably between 200 and 250 patients now, where we will trial it in clinic, some of them just for a session or two or some people it's in their own home if I'm seeing them there.
And from [00:28:00] that, we'll then decide is it worth a longer trial of a couple of weeks to see what sort of impact? And some people don't notice any benefit until we withdraw it and stop using it and they're like, oh, actually this is having an impact on my sleep, or something of that nature.
Jill Brook: So how long do you usually have your patients do it for per day?
Caelum Schild: Yeah, so typically because there is such variation in terms of response, 'cause we can, we can hit that brake pedal too hard for people as well. Um, so going back to that analogy of for some people we can overstimulate the vagus nerve and that can ironically present as feeling too parasympathetic, so too lethargic, too heavy.
So what we typically do is start off with, for, for someone who's really, really sensitive, it could even be one minute per day. But typically, depending on how people are tolerating things about five minutes [00:29:00] a day. And then they can slowly titrate it up if they feel like they're not hitting the brake pedal too hard.
And that can gradually increase really until people start to notice some sort of improvement. And I guess a good clinical compromise if someone doesn't feel that improvement in terms of symptoms, but they may want to use it for other means, a good compromise might be between 15 and 30 minutes per day of seeing some of those benefits with some of the, the inflammatory markers, but not having the time to be able to do something that may not improve their symptoms.
Jill Brook: So that's great. And so you provide that to your patients so that they don't have to go out and spend a few hundred dollars and buy one. They can try yours first and see if they're benefiting.
Caelum Schild: Correct. Yeah. Yeah. So we've got a few different ways that we can do that, but we, we will just do it during an [00:30:00] appointment for people, if I'm seeing them face to face. It's a bit more difficult to do that if I see people via telehealth, unless they have a device themself. But yeah, we can try that a few times.
We're looking at starting a little bit of a program that we can provide some education around what vagus nerve stimulation is, help people with that, and then provide them with a loan machine for six or eight weeks so they can actually give it a go before they go and then, and purchase it as well.
But yeah, that's something that I, I guess I'm really big on because it's really costly to, to live with POTS with all of the strategies that we have to implement. So if we can try something before we have to buy it, it's, it's a, it's a big win in, in my books.
Jill Brook: Amen. Very cool. Okay, so is there anything else to say about the vagal nerve stimulation before we move on to the next therapy?
Caelum Schild: Yeah, so probably the only other thing to mention just [00:31:00] for people, I guess a bit like yourself, where you're like, is this something that may or may not help for me of, I guess clinically what we tend to notice of, is there a difference between people who might respond and may not respond without actually being able to trial?
What we notice from a, from a clinical sense, so it's not research, but certainly clinical observation of people who have more of a hyper adrenergic presentation with their POTS, are people who we typically will notice perhaps a little bit more benefit from something like the, the TVNS than others who may have a slightly different presentation with their POTS.
And obviously no one person with POTS is typically sort of bound by just the hyperadrenergic presentation, so how much of a factor that is for people will be very will, will vary as well, so.
Jill Brook: But that's great, great information. Fantastic. Okay, and so you had said one of the things that the vagus [00:32:00] nerve stimulation was found to affect and improve was the heart rate variability. Do you wanna talk about what that is and how you use it?
Caelum Schild: Yeah, so that's another area that I love working with, with people. A bit like I sort of touched on before, it, it gives us something objective to be able to look at, at home essentially. To be able to give us a bit of an understanding or more of an understanding of how a nervous system might be responding
I guess uniquely for that particular day, but also as a whole, over a lengthy period of time as well. So as we start to implement changes, what sort of trends are we seeing and, and those sorts of things. So heart rate variability, I guess in this instance is something that we're looking more so at the time domain. And so that is very small changes in each beat and the time [00:33:00] between each beat of our heart. And the thing that obviously impacts that quite profoundly is our autonomic nervous system.
And they're so small, those changes, that they're measured in milliseconds. So they're, they're really, really small and, um, HRV as a, as a mechanism is something that's really personal. So your HRV will be quite different to, to mine for instance. So it's really difficult to compare heart rate variability between people or even POTSies.
But something that we can do is look at our own heart rate variability compared with our own personal baseline to give us some insight into our nervous system.
Jill Brook: And the thing that always sort of seems counterintuitive to me is I think higher variability is better, like right, like you don't actually want your heart rate to be perfectly uniform. You [00:34:00] want it to be a little like irregular from beat to beat.
Is that right?
Caelum Schild: Yeah. Yeah. So, and this is one of the things, I guess. And it's so interesting to, to look at. And the reason for that is because our autonomic nervous system is constantly interpreting information that's fed through all of our senses and and determined by our brain. And so because we are biological systems, our bodies need to respond to all of those different bits of information quite quickly.
And that is partly driven by the autonomic nervous system. Um, and they did a study on POTS, a review study, might have been 2019, looking at heart rate variability as a POTS group as a whole, and a healthy control as a whole. And saw the POTS group had a reduced heart rate variability and I guess that has left a lot of people when they look at HRV of, oh, I just [00:35:00] want to get it higher.
And as we'll hopefully chat about a bit more, when our HRV is higher for a particular day, it may not actually always mean that we feel great. It might mean that our body is in actually an overly freeze or parasympathetic nervous system state for that particular day. As we see those changes in the nervous system occur by the body, trying to maintain that, that homeostasis what we can see is that the body, particularly if our body is having quite a, an overly sympathetic response for a period of time, that's really exhausting on our body and uses a lot of resources and energy and the body will try and like push us towards a more of a parasympathetic state to be able to help with recovery.
And that's when we will often start to feel, yeah, really heavy. Um, a lot more lethargic fatigue rather than that real [00:36:00] wired tired sort of fatigue. And oftentimes, I know me personally, those overly parasympathetic days compared to my baseline are the ones where I feel a lot worse because my heart rate is usually lower and my blood pressure's also really low.
So we get heaps less blood coming back up and together with that really heavy lethargic often for me it's, it's flu sort of symptoms as well on those days for people. It's quite a common presentation across the, the people that I work with where for that day, if, if we're seeing more of a parasympathetic state, it may not always be an ideal state for our body.
Jill Brook: So can you talk a little bit more about how you use this in the clinic and how you measure it? So, do you have people wear like a, a device that is giving you real time feedback or how, how does it work and how do you use it?[00:37:00]
Caelum Schild: Yeah, so I guess that's where it's come from historically. So historically with things like ECG devices and Holter monitors is where it is, is the only way really that we could get heart rate variability insights. But where it's much more useful clinically is with some of the technology in recent years.
So sort of the last decade to two, we've started to see chest strap heart rate monitors, and even smart watches and apps built into our phones that analyze blood flow in the context of apps and and smart watches and chest straps monitor the heart rate itself in terms of electrical signals.
What we can then do is, is with an app is to start looking at what someone's personal baseline might be. And once we've established someone's personal baseline, we can then [00:38:00] get a, get some feedback either from their HRV overnight with say, a, a watch, a smart watch or a morning check in at a really standardized time, in a standardized way to be able to capture their heart rate variability and then provide them with some insight into where their body is for that day.
Jill Brook: And so, for example, I know some athletes, my, my hearing about this is not that, that recent, so this might be out of date by now, but I know for a while I was hearing about athletes who would measure their heart rate variability, and they would, on a day where their heart rate variability was high, they'd say, okay, I can do a really hard workout today.
But on a day when their heart rate variability was low, they'd say, oh, I should take it more easy today. Is that valid? Is, is that something that you do? Or how, how do they think about it now?
Caelum Schild: Yeah. Yeah. So that's essentially what what we'll look at. And that was actually my [00:39:00] own personal experience with it as well of like my first experience with this chest, chest strap, heart rate monitor is what we had at the time. I guess probably 12, 12 to maybe 15 years ago when I was still attempting to partake in sport and monitoring this, and obviously seeing these wild swings between sympathetic and parasympathetic.
But yeah, in more recent times what we've been able to do is adapt some of that, that use for athletes across to using it for invisible illness and I guess how we look at it with invisible illness rather than low HRV, back off and high HRV is sort of go, is with invisible illness oftentimes it's, if it's within our personal baseline and context is really important for POTS.
So, and that person is feeling like they're not having a, a horrendous day as well, so it's really important to, to consider symptoms [00:40:00] that we can then probably proceed, proceed forward with, say plan A. If we're looking at, say, uh uh, like a plan of strategies, and then if their heart rate variability is actually lower than baseline, we might look at a plan B.
And then if that HRV is much higher than baseline, we might implement a plan C. So it really helps us kind of individualize and personalize that that approach for the day.
Jill Brook: Do you see, or do you know of any findings around people with post exertional malaise or myalgic encephalomyelitis and what their heart rate variability does?
Caelum Schild: So there was a paper looking at that as well on heart rate variability as a cohort, which was almost identical to POTS. So as a cohort, their HRV was lower than the healthy controls. And so really similar in terms of how we look at that and approach that, as what we look at [00:41:00] with POTS. And I guess that that low heart rate variability finding is not necessarily unique in the context of invisible illness.
So if we look at a lot of chronic illnesses, so even looking at research such as MS, which obviously has a lot of autonomic overlap as well. Some cancers as well. They've looked at heart disease and a lot of those do also indicate lower heart rate variability compared to, to the general population.
So whether that is because of some of the inflammation associated with these conditions or the autonomic impacts. That's the tricky thing with HRV is it's not super specific, but it's really sensitive.
Jill Brook: And, and that's so interesting. And so I wanted to ask you, it seems like we hear about some POTS and invisible illness patients who make these great recoveries and then we hear about others [00:42:00] who they do all the right things and they put in the time and the effort, and they don't improve very much. Do you clinically notice anything that predicts which of your patients tend to have better comebacks or...
Caelum Schild: I, I don't and, and it's really hard. Like I wish, I wish I, I did. And I think it is a broader reflection of that heterogeneity of POTS and, and how individualized, I guess, each person with POTS is. So I guess if you've met, although we all have overlaps, if you've met one person with POTS, you've sort of met one person with POTS and the next person will present a little bit differently.
And and I guess as an example, a couple of examples of that, like there are some of the elite athletes that I've worked with over the years that unfortunately they can only return back to maybe very minimal light exercise and had a lot of [00:43:00] difficulty getting past that. And then on the flip side, we have some people who have been bedbound for years and make incredible improvement once we've sort of been able to understand fully what's happening with their body and, and really exhaust and try all of those strategies.
So it's, yeah, I guess, over a lengthy period of time though, if we can accumulate those things in our toolkit by learning and trialing things and, and understanding how they may be helpful or not helpful and place them in our toolkit or exclude them from that toolkit or maybe to retrial in the future, we can see improvement.
But yeah, unfortunately we still see people where they can't get back to, to reaching those goals that they would would want to.
Jill Brook: So let's end with something really optimistic. Can you tell us a story of one of your POTS patients who was like what you just said, where they maybe were, were sort of home bound or [00:44:00] even bedbound and ended up being able to recover quite a lot. Like
what did you do? What were they able to do at the beginning and at the end?
And like, what, what um, therapies did you use with them?
Caelum Schild: Yeah, I've got a couple of quicker stories, um, that kind of come to mind immediately. One, one really recently that I've that I've reviewed and, and ironically somewhat, this person had quite a flare. I was working with them beforehand, but they had quite a flare around the time of our POTS conference here last year, so that was March, 2024.
And now we fast forward a bit over a year and they had a substantial flare to where they were back in bed. Their management was, was all over the place and they had to have some, some adjustments medication wise. And we went back to sort of basic non-pharmacological management. This person's goal was to get back doing some running.
And bearing in mind at that time, they couldn't walk, um, [00:45:00] really from room to room. And so we had gradually sort of worked on that and stabilizing with their cardiologist over, over a period of time. And they've actually just completed a half marathon a couple of weeks ago, which is quite
incredible.
Um. So, yeah, and, and in that case it was a combination of everything. So it wasn't just my input obviously, it was some of the medications that needed adjustment and really touching on the, the salt fluid diet and, and support. And yeah, they, they were able to get back to doing that half marathon, which was quite incredible.
And I guess the other one that comes to mind as well, if I can quickly touch on it, is someone who, again, quite, quite incredible progress, um, where this person was bedbound for quite some period of time with an ME/CFS diagnosis, but then wanted to explore a POTS diagnosis a little bit further to see how much that might be an influence for them.[00:46:00]
And we've implementing all of the POTS management strategies. Um, so salt, fluid, compression, the movement, pacing and the addition of a few medications as well as person over a good few years has progressed to the point where they've been able to get back to uni, study, and now into the workforce and, and looking at getting into a, a house of their partner and moving to, to a different place.
And so it is given them a whole new lease on life, which is quite incredible.
Jill Brook: Oh, that's great. I mean, yeah, it's, it's absolutely amazing how different every POTS patient is, and it's funny because I, I realize that people like you, you could have taken probably a much easier professional route and worked with a community where it was just cookie cutter, do the same thing every time.
And I, I know that the POTS patients don't make it easy for you every time you have to really think.
Caelum Schild: Yeah, but that's what I like, I guess. For me, that's what I love, like that investigative [00:47:00] work that we have to do with POTS is, is so, I guess, rewarding for myself, but it's something that I do find actually really enjoyable and, and and fulfilling. And even those small gains, I mean, those couple of instances there were, were, were quite remarkable examples.
But even the small gains that we all see every day are, are incredible and we need to celebrate those as well.
Jill Brook: That's a good point. When I was at my worst, I used to always remind myself that going from zero to one is the only time you get a boost of infinity and going from nine to 10, that's, you know, that's almost nothing. Going to zero to one is the real, is the real
Caelum Schild: A hundred percent. Yeah, zero to one, and then it's double from one to two, and it gets that little bit easier each time from there. But yeah.
Jill Brook: Yeah. Well, thank you so much. We're so, um, we're so excited to get to know you and to see how knowledgeable and dedicated you are to this community and to have you as a resource. Do you have any final thoughts or parting message for people?[00:48:00]
Caelum Schild: Yeah, I guess from, from my side of things is just continue to, to find that team around you and surround that team or surround, uh, yourself with that team that is going to work with you. They don't need to be a POTS expert necessarily. And I know you've mentioned that numerous times of just finding those people around you that are willing to work with you and to, to help do that investigative work and, and to help support you along the way.
And I guess the fact that like POTS is a really challenging condition to live with and, and for us as health professionals as well to, to manage, but I guess going back to that toolkit analogy before of if we can keep putting things in that toolkit that we can call on, we can see some really steady progress over time.
Jill Brook: Awesome. Awesome. Well, thank you for always looking for the next good tool. Where can people find you online if they want to learn more about your clinic.
Caelum Schild: Yeah. So, I guess our, our website is probably a good spot, so [00:49:00] that's just loftyhealth.com.au. We've got Facebook and an Instagram. It's not overly used, but we, we do have the, the socials there. And for me personally, I guess more so professionally if people want to connect, I am on LinkedIn as well.
So just through my name Caelum Schild. But yeah, thank you so much, Jill. It's been amazing to chat with you today, so good.
Jill Brook: Well, likewise, thank you so much. We'll put all those links in the show notes, so if anybody wants to find you easily, they can just go there and click. So Caelum, thanks a million. It's been great talking to you. And okay, listeners. That's all for today. We'll be back soon with another episode, but until then, thank you for listening, remember you're not alone, and please join us again soon.