Number Check: Heart Rates and Children with Rashmi Rao, MD

Podcast Transcript

John Horton:

Hey, there. And welcome to another Health Essentials Podcast. I'm John Horton, your host. Do you know your child's heart rate? For parents of previous generations, the answer was probably a resounding, no. Today, though, gizmos and gadgets that track biometric statistics often put that kind of information a click away on an app. Heart rate data is just, well, there for parents or any young athlete to look at. What do those numbers really mean, though? And is there a point where you need to worry about whether your kid's heart rate is spiking too high?

Questions like that deserve answers, which is why we asked pediatric cardiologist Rashmi Rao to join us today. Dr. Rao is one of the many experts at Cleveland Clinic who visits our weekly podcast to help us better understand health data and what it means for us. So, let's make some sense of your child's heart rate so your mind can rest easily while they play.

Dr. Rao, welcome back to the podcast. Always great having you on.

Dr. Rashmi Rao:

Hi, John. Thanks for having me.

John Horton:

So, before we start getting into our topic today, let me ask you: What drove you into pediatric cardiology and wanting to work on young hearts instead of old tickers like mine?

Dr. Rashmi Rao:

Well, I always knew I wanted to do pediatrics. That was something that I always enjoyed. Working with kids is really a passion of mine. But I'll be honest, until I started my training, I wasn't clear on really wanting to pursue cardiology. But when I rotated through cardiology during my pediatric residency, it really just spoke to me. I understood things, they made sense. And I really enjoyed a lot of the learning and discovery that happens in our field.

John Horton:

Well, we're glad you're in it and we're glad that you're here to help us learn a little bit. So today, our topic is on heart rates - which, I think, is talked about a lot more, probably because everyone's got these watches on now that tracks it. Do you get a lot of questions from parents about their kids' heart rate?

Dr. Rashmi Rao:

Absolutely. Certainly, one of the more common reasons kids - and particularly adolescents - come to see us is because, I think, they're the ones who tend to have these smartwatches and are obsessively keeping track of their heart rates throughout the day. So certainly, a lot of questions about heart rates, yes.

John Horton:

So, what can you tell us about it? I know as an adult; you always have these ideas with your max heart rate and where they should be at. Do those numbers line up with what kids should see?

Dr. Rashmi Rao:

Not really. And that's a great question because I think we all identify heart rates and exercise in terms of a maximum or a target heart rate, but we can't really correlate that formula to kids.

So, in adults, we tell people to subtract their age from 220 and that's really their target zone. But for kids, heart rate actually varies throughout childhood.

When babies are born, their heart rates are actually quite fast. And then, as you grow towards adolescence, and as you get towards late adolescence, your heart rate is more normal in terms of what we'd expect from an adult standpoint. So, using that formula across the board for kids doesn't really work because it might end up estimating a heart rate that's really too high for a kid in terms of their maximum.

John Horton:

Yeah, I was going to ask, so should kids be higher or lower on that? If you used that 220 - if you had a 15-year-old - using that 220 minus the age, you'd say their max heart rate should be 205. Is that then, higher than it should be, or lower?

Dr. Rashmi Rao:

That's probably higher than it should be. If you're exercising, you can certainly reach that if you're at high intensity, but that's not necessarily where you want to target.

John Horton:

So where should kids look to go? Because we have these watches and all this data that comes to us. What heart rate zone or heart rate number should they target?

Dr. Rashmi Rao:

Honestly, I think for kids, it's really more driven by how you're feeling and what your goals are. There's certainly low-impact exercise, just walking and probably normal, regular play that most kids engage in, and I wouldn't necessarily fixate on the heart rate during that type of exercise or play. And then, as you get to more moderate or high-intensity exercise, your heart rate is clearly going to be higher the more intense your exercise goes. But I don't know that there's any set number that we'd want to target for kids.

As you approach, I think at age 18 or so, you're probably more in that adult realm and can apply the formula of 220 minus your age. But I think for adolescents and kids, it's really by how you're feeling. So, the goal is to get a little short of breath - you still want to be able to talk - and see an increase in your heart rate, and that tells you that you're working hard. If you get to a point where you're really pushing too hard and you're feeling symptoms of dizziness or really short of breath where you can't even get a word out, that's a time that's probably where you're pushing too hard, where the heart rate isn't necessarily going to tell you that.

John Horton:

So, you go more by feeling. It's hard. I know we're in such a metric-driven world, everyone likes to look at these numbers and think that they give you some magic conclusion. But is this one of those where you just go with how you're feeling, and you listen to your body?

Dr. Rashmi Rao:

Yeah. And kids are probably better at doing that than adults.

John Horton:

Probably. And do you find that, I mean, will kids just naturally, are they more willing to shut down when their body starts getting to that point where it's maxing out?

Dr. Rashmi Rao:

I think so. I think particularly younger children and probably early teens are more apt to listen to their body. I'm sure as you get older, and you're really trying to push harder, kids might get in danger of trying to push too hard.

John Horton:

Now, if you're a coach or a parent or somebody and you're working with young kids and putting them through physical activities, what should you be looking for to make sure that they stay safe?

Dr. Rashmi Rao:

Sure. I think again, just really focusing on how the kid is doing in terms of their symptoms. Certainly, the goal is to get sweaty, to breathe hard and to increase the heart rate. But if you start to see somebody looking like they're off balance, maybe they're showing signs of dizziness or lightheadedness, they're really short of breath, working very hard to breathe — those would be times where I'd probably encourage them to stop and take a break and drink some water.

John Horton:

And I was going to say, what should you do in that situation? Obviously, stop. But then, are there other things you should do to help them recover or to watch for?

Dr. Rashmi Rao:

Sure. I think if somebody's feeling dizzy, laying them down is probably a good start because you want to get your head and your heart at the same level so it's easy for blood to get to the brain and prevent them from fainting or something like that. And then, certainly, rehydrating is probably a good first step as well.

John Horton:

How quickly do kids usually bounce back when that happens, and you lay down and just take it easy for a few minutes?

Dr. Rashmi Rao:

Pretty quickly. I'd say within minutes, most kids are ready to go again, depending on how hard they've pushed themselves.

John Horton:

The power of youth, you know?

Dr. Rashmi Rao:

Yes.

John Horton:

So obviously, we've been talking about exercise and maxing out your heart rate but resting heart rate is also something. Where should that be with kids?

Dr. Rashmi Rao:

So that really just depends on the age. There are normal values as you progress through childhood in terms of heart rates, that range for age. So, in a baby, a heart rate ranges from 100 to about 180 or so is normal. Whereas for a 12-year-old, that would be a little bit high. So really, it depends on the age of the child. Babies tend to have much faster heart rates. As you get to school age, anywhere from 80 to 120 or 130 would be pretty normal. And then, as you get into adolescence and closer to adulthood, getting more in the around 80 to 100 or so.

John Horton:

So overall, with heart rates, as you get questions from parents, what do you tell them as far as what they're looking at and what they're worried about?

Dr. Rashmi Rao:

Well, many times, people will notice that just with sitting, their heart rates might be particularly elevated. And this, again, tends to be more of an adolescent issue. So, they also have smartwatches. And they may notice that they're just sitting and resting, and their heart rate is persistently 120 or so. That's too high for a resting heart rate for a teenager, for example. And so that would be a situation where it would be worthwhile coming to see us and doing some testing to see, is this a pattern that exists most of the time? And is there a reason or do we need to look into this further?

John Horton:

Now, if you start noticing some unusual activity and heart rates are jumping around, what's typical practice? If somebody comes in and they see you, what happens after that?

Dr. Rashmi Rao:

Oftentimes, if you come in with a complaint that your heart rate is abnormally high, and you're not exercising and it's just at rest, then our first step would be to do a monitor. Something called a Holter monitor, or an ambulatory monitor, which basically monitors the heart rhythm and heart rate over a period of time, like 24 to 48 hours, and then gives us all of this data to look through. And we ask families and patients to correlate their symptoms. So, if they're feeling something at the time that they should make a note of that, so we can then correlate what we're seeing on the monitor with what they're feeling.

John Horton:

So, it sounds like a heart rate's, it's an important tool, obviously, or measurement to take. You get a lot of information out of it, but don't get overly concerned with numbers that you're getting off of your watch.

Dr. Rashmi Rao:

Correct, yes. Your body responds to a lot of different things. So, your heart rate is in response to how you're feeling, what you're doing. If you're scared, excited, nervous, those are all reasons that the heart rate might be a little bit high, even if you're resting. And certainly, if you're exercising or have just exercised, it's expected for the heart rate to be higher.

John Horton:

Do kids even have more variety in that? Because obviously, when you're young, just everything is, your body's going nuts all the time. Does it just jump around naturally?

Dr. Rashmi Rao:

It can, because I also think kids' emotions are all over the place, too. They might be anxious one minute and feel fine the next. Or they're excited about a video game they're playing, and that can certainly drive your heart rate up as well. So sure, there's a lot of variability that can occur.

John Horton:

Overall, with parents then, should you pay attention to these heart rate numbers that you see? Or just focus more on just how your kid is feeling and doing?