Guidelines With Gabi:
Not for the Faint of Heart: Pediatric Syncope

December 16, 2022

On today’s episode of Talking Pediatrics, Dr. Gabi Hester will talk with one of our Kid Experts, Pediatric Cardiologist Dr. Ian Thomas, about pediatric syncope and in particular red flags and initial workup for cardiac causes.


Dr. Angela Kade Goepferd:  This is Talking Pediatrics, a clinical podcast by Children’s Minnesota, home to The Kid Experts, where the complex is our every day. Each week, we bring you intriguing stories and relevant pediatric health care information as we partner with you in the care of your patients. Our guests, data, ideas and practical tips will surprise, challenge and perhaps change how you care for kids.

Welcome to Talking Pediatrics, I’m your host, Dr. Angela Kade Goepford. Watching a child go limp and unresponsive is possibly one of the most terrifying things that any parent or pediatrician will experience. On today’s episode of Talking Pediatrics, Dr. Gabi Hester talks with one of our Kid Experts, pediatric cardiologist Dr. Ian Thomas, about pediatric syncope and particular red flags and initial workup for cardiac causes.

Speaker 2: Welcome to Guidelines with Gabi.

Dr. Gabi Hester: Today we’re going to be covering a topic very dear to my heart, pun intended. Watching a child go from alert and active to limp and unresponsive is heart-stopping for any caregiver. Up to 15% of kids will experience an episode of syncope during their childhood or teen years. Thankfully, most of these terrifying episodes are from benign causes. However, on occasion, they may represent a more concerning diagnosis.

Today we’ll be talking about some of the causes of pediatric syncope and then we’ll zero in on the question every healthcare provider asks, is it the heart? I’m excited to be joined today by one of our kid experts, Dr. Ian Thomas, pediatric cardiologist at the Children’s Heart Clinic. Welcome, Ian.

Dr. Ian Thomas: Thank you for having me.

Dr. Gabi Hester: So first to be clear, so syncope is not usually caused by issues with a heart. So, I do want to first sort of set this up by talking through some of the more common causes. So, before a kid would come to you in your heart clinic, what are some of the things that would’ve been ruled out or at least thought through before the patient would get there?

Dr. Ian Thomas: I think a lot of it depends on the age, and as you mentioned, the vast majority of causes of syncope are non-cardiac, and we take the age into consideration as far as what the red flags are and things like that.

Dr. Gabi Hester: Let’s talk real really briefly about a couple of the more common ones. So, if you think about vasovagal syncope or breath holding, what are some of the key features that we might see in those, which age groups and stuff? Tell us a little bit about some of those more common things.

Dr. Ian Thomas: Sure. Vasovagal syncope is extremely common and it tends to occur in teenagers. I tend to see it starting around 10 years of age, maybe a little younger, typically peaks as far as patients that I see in the mid teenage years. Vasovagal syncope typically has prodrome prior to the fainting and it typically starts with dizziness and lightheadedness. Sometimes people feel their heart beating fast and then sometimes they have some nauseousness or a flushed feeling, followed by visual changes or auditory changes, and then the passing out happens. That’s the typical progression of symptoms for vasovagal syncope.

Dr. Gabi Hester: I feel like a lot of us in our medical training, at least I’ll speak for myself, experienced vasovagal syncope on a fairly routine basis, not being well-hydrated and being under a lot of stress. What about some of the younger age groups, kids who aren’t teens quite yet, school-aged kids, what are more common causes of syncope in that age group?

Dr. Ian Thomas: So in younger kids, so say like under four years of age, four to five years of age, other causes of syncope are things like breath-holding spells, which tend to occur with crying, with a sudden loss of consciousness, and those can recur over time. In the five to nine year age range, it’s less common for me to see syncope in clinic and that always is a little bit of a red flag, things like seizures, and in some patients that are on certain medications that may cause low blood pressure, we may still see the vasovagal syncope or orthostatic hypotension that could cause syncope as well. But that four to nine age range is always a little bit more concerning when I see them in clinic.

Dr. Gabi Hester: As a hospitalist or a general pediatrician, considering you mentioned a few of these seizures. A little less common would be things like migraine syndromes. Again, typically in that older teenage group, similarly conversion disorder, panic. You can see syncope with hypoglycemia and things like toxic ingestion. And certainly right now with lots of snow on the ground, heat illness would not be on our differential, but something I’d be considering in the hotter summer months. You mentioned age a little bit, but tell me a little bit about how you approach such a broad differential diagnosis?

Dr. Ian Thomas: Oftentimes, by the time they get to me, there has been some level of workup done and that usually entails a CBC and a BMP. So electrolytes, blood glucose, and hemoglobin to evaluate for things like anemia. Sometimes kids have an EKG that’s already done. Every kid that comes into clinic with a diagnosis of syncope always gets an EKG because that’s a easy thing to do, low cost, and it’s a screening tool to evaluate for those types of syncope that may be less benign, like the arrhythmias and things like that.

Dr. Gabi Hester: And certainly, getting the lab tests, most clinic settings will have CBC and BMP and even some might have EKG. What are some of the history questions that general providers should really dig into, to help sort through what might be causing the fainting episode?

Dr. Ian Thomas: The thing with syncope, is that if you take a detailed history and physical exam, it almost always it can lead you to the diagnosis. My typical questions that I like to ask is, in what setting did the syncope happen? Were they at rest or was it during exercise? Was it associated with a positional change or some type of intense stimuli like seeing blood, or getting a vaccine, or sitting in health class or something like that.

And then I always ask about those prodromal symptoms that we discussed a little bit earlier, any accompanying symptoms prior to the syncope? Things like dizziness and lightheadedness and that kind of thing. And then whether or not they felt their heart race. It’s also important to … on the back side of the syncope, so how long did it last for? How quickly did they return to consciousness and how long the process was for them to return back to baseline. If it was a longer period of significant drowsiness, like a postictal state, then I’d be worried more for seizures. But oftentimes, patients would say like vasovagal syncope, return back to baseline relatively quickly.

Dr. Gabi Hester: Are there any family history questions that we should be specifically asking patients like this?

Dr. Ian Thomas: Yes, the family history is very important. Oftentimes it is completely benign, but the important questions to ask in family history from a cardiac standpoint, is any family history of arrhythmias, particularly in young people, like under the age of 50. And any family history of sudden or unexplained death. So, say like a death that occurred after jumping into a swimming pool or like a one-person car accident that was unexplained. Things like that could cue you into those kind of pathologic arrhythmias that we worry about.

Dr. Gabi Hester: So, I think we’ve mentioned some of these as you walked through some of the history taking questions. Tell me a little bit about red flags that I should be alert to that might indicate cardiac involvement.

Dr. Ian Thomas: So, red flags in the history, the things that make me a little bit more nervous, are unprovoked syncope. So, if they’re just sitting on a chair at the kitchen table and they pass out unprovoked, that would be a cause of concern. The lack of a prodrome, so no dizziness or light-headedness, and that typical kind of onset of vasovagal syncope would be a red flag. Younger age. So under the age of nine, I tend to be more aggressive in as far as how I evaluate syncope. And then any syncope with activity, although the vast majority of activity related syncope is vasovagal syncope, is always more of a cause of concern and may require additional workup.

Dr. Gabi Hester: So, once you’ve ruled out in some way, whether it’s based on lab testing, or cardiac testing, or history, some of those other causes that we mentioned, seizures, ingestions. When you’re thinking about the heart, you mentioned maybe EKG is an initial test. Are there any other tests that folks out in the primary care setting or emergency department should be obtaining to look at the heart before they would contact a cardiologist?

Dr. Ian Thomas: Specifically looking at the heart, I think an EKG would be an appropriate first test. The other thing that you could do in an outpatient setting is orthostatic testing. So, what their blood pressure and heart rate is when lying down and then having patients stand up, waiting for a few minutes and then repeating a blood pressure and heart rate. And there’s certain diagnostic criteria that would tell us that this is a positive orthostatic sign and they’d be at risk for something like vasovagal syncope. But that’s pretty much the first step that I would take prior to referral to a cardiologist, EKG and orthostatic testing.

Dr. Gabi Hester: And when you’re thinking about all the different potential cardiac causes of syncope, are there categories that you tend to group them into or how do you work through that process?

Dr. Ian Thomas: I guess the broad cardiac categories would be an arrhythmia-driven event, and there’s a lot of subcategories to that, obviously. Less common would be congenital heart disease as a cause, or cardiomyopathy. Things like hypertrophic cardiomyopathy and dilated cardiomyopathy. Much more rare, particularly in teenagers would be pulmonary hypertension, like primary pulmonary hypertension, that could cause syncope.

Dr. Gabi Hester: Within those buckets, so you mentioned arrhythmia. Are there some of the more common causes within arrhythmia itself? I know we’re going down different layers deep here, but are there some that are more common than others as far as arrhythmias?

Dr. Ian Thomas: A lot of those can be evaluated for on the EKG, and that’s the main reason why we get the screening EKG. So things like pre-excitation syndromes like wolf Parkinson white pattern, the typical delta wave that we see with the shortened PR interval is a common cause for arrhythmia, not a common cause for syncope, but if you see that on an EKG with syncope, that is a cause of concern. Long QT syndrome, Brugada pattern or Brugada syndrome on EKG, are all the typical more common things that we would see. Although they are uncommon, those are the things that we commonly evaluate for on EKG.

Dr. Gabi Hester: So, now we’ve found this needle in the haystack, we’ve identified a cardiac cause when typically it wouldn’t be cardiac. Are there any cool new treatments or how do some of these kids get managed?

Dr. Ian Thomas: Yeah, it really depends on the cause. For something like a pre-excitation syndrome, we would typically have the kid undergo an electrophysiology study and potentially an ablation, to get rid of that alternative pathway that exists that can cause the arrhythmia. And as far as treatment for the other types of arrhythmia, it varies and there’s not great treatment for it. There’s other ways to evaluate for it, like Holter monitors. Longer term, we use something called a Preventice patch here, which is nice in kids because it’s waterproof and activity proof.

So, in that next step, so say kids come in, they get an EKG, the EKG doesn’t show anything, but there are some kind of concerning considerations in their histories, such as syncope with activity or lack of prodromal symptoms. I’ll oftentimes put a longer term heart rhythm monitor on, to see what their heart rhythm is during, hopefully we capture one of these episodes during one of the episodes, and that is another way to rule out or rule in arrhythmia.

And so, that’s been something that I utilize quite frequently in these kids. Other testing options would be a stress test, so putting them on a treadmill and trying, particularly with kids that are fainting with activity, trying to recreate that intense exertion where they passed out and seeing what their heart rhythm is and blood pressure response is to activity.
If they’re happening really sporadically with long periods of time in between the episodes. And sometimes we’ll put in these loop recorders, which are implantable devices that allow us to see what the heart rhythm is at the time of an event. And those can be placed for a couple years. So, like Medtronic just got FDA approval to be using those in kids. So those are capabilities that we have that, with those kind of higher risk kids, or what we would consider the kids with those red flags, that we may consider doing.

Dr. Gabi Hester: It sounds like there are some cool technologies for understanding or better characterizing rhythm problems. What about structural issues? Are there any new advanced imaging techniques that can be used in that type of setting?

Dr. Ian Thomas: We typically would start with an echocardiogram to evaluate for structural issues, whether that be congenital heart disease, pulmonary hypertension, or cardiomyopathies. If we do find concerns for say, hypertrophic cardiomyopathy, the next step would be a cardiac MRI or even a cardiac CT, depending on what the structural abnormality is. And fortunately, we have the capability of doing those CT scans here. At Children’s, we just got a brand new state-of-the-art CT scanner and we’ll be getting a new cardiac MRI scanner within the next couple years. And those give us the ability to look at the heart tissue in finer detail and make more detailed measurements, and further risk stratify kits depending on what their diagnosis is.

Dr. Gabi Hester: So, we’ve talked about how vasovagal syncope is one of the most common causes of syncope. What are some of the initial recommendations that you would give to kids who are experiencing this?

Dr. Ian Thomas: The mainstays in treatment for vasovagal syncope is avoidance of dehydration, good salt intake, regular exercise, and regular sleep. What I generally recommend for fluid intake is about 80 ounces of water a day or more if they’re very active. I recommend families set … particularly in teenagers, set an alarm on their phone for like 8:00 AM, 11:00 AM, and 2:00 PM and have a 30 ounce water bottle, 32 ounce water bottle, and then just drink the bottle of water when their alarm goes off.

As far as salt intake, a goal amount of salt intake is at minimum about five grams a day. And generally, that means adding more table salt to your food or having a few extra salty snacks. They make these electrolyte packets these days. A common one that’s used is called Liquid I.V. and that can be added to your water, and that can be helpful just getting more salt and other electrolytes in. I don’t generally recommend just drinking Gatorade or Powerade because of the sugar in those drinks.

Dr. Gabi Hester: You mentioned regular exercise. Can you talk a little bit about how that relates to vasovagal syncope?

Dr. Ian Thomas: Regular exercise, so deconditioning can be a cause of vasovagal syncope. I mean, I saw this a lot during COVID shutdown time, where kids were just sitting around and not doing anything. When they started getting up and running around again, everyone passed out. And so, regular exercise is very important to improve symptoms, and I really recommend at least 30 minutes of any type of activity a day, whether that’s walking your dog around the block, walking up the stairs in your home, or participating in a sport, anything is helpful. And then getting good sleep hygiene. A tired brain doesn’t communicate with your body as well, and those kids are at an increased risk of having syncope too.

Dr. Gabi Hester: We covered a lot today, thinking through a really broad differential of syncope. Talked a little bit about some of the common causes being non-cardiac, vasovagal syncope in older kids, teenagers, breath-holding spells in the younger kids, and then zeroing in on some of the cardiac causes. So, it really sounds like if I’m seeing a kid with syncope in my general practice, I should probably just call a cardiologist right away, I’m guessing, huh?

Dr. Ian Thomas: It depends a little bit. If they are teenagers that aren’t drinking any water and have dietary restrictions, or restricting their diet for some reason and have all of these prodromal symptoms, where they’re dizzy and lightheaded and nauseous before passing out, I would actually first start by saying, increase your fluid intake and increase your salt intake. And if things don’t get better after that, then we’d be happy to see them. But the vast majority of kids, even in kids I see that are referred to cardiology for more significant symptoms, the vast majority of those kids get better with really focusing on salt and fluid intake.

Dr. Gabi Hester: It’s important to think through those red flags that you mentioned. And so I think helpful for all of us seeing these kids out in the community and in clinics and emergency settings to think through, when we do need to take the next step in workup and consultation. So, thank you so much for joining me today. I really appreciated having you here and getting to talk to you.

Dr. Ian Thomas: Yeah, it’s my pleasure. I see a lot of kids in clinic with syncope, and I’m more than happy to share my experience with you guys.

Speaker 2: Take home points.

Dr. Gabi Hester: Number one. Syncope has a broad differential. Most commonly in teenage patients, this would be vasovagal syncope. In younger children, breath-holding spells might be seen. However, cardiac and neurological causes should always be considered.

Number two. Red flags for cardiac causes include if the syncope is unprovoked, if there’s no prodrome, age less than nine years, syncope with activity, any concerning family history, or of course, an abnormal EKG.

Number three. If the cause of syncope is not readily apparent after a thorough history and physical examination, initial cardiac testing to consider would be an EKG.

Number four. Treatment for the most common cause of syncope, vasovagal syncope, would include good hydration, good salt intake, regular exercise, and getting adequate amounts of sleep.

Dr. Angela Kade Goepferd: Thank you for joining us for Talking Pediatrics. Come back each week for a new episode with our caregivers and experts in pediatric health. Our executive producer and showrunner is Ilze Vogel. Episodes are engineered, produced, and edited by Jake Beaver. Amy Juba is our marketing representative. For more information and additional episodes, visit us at, and to rate and review our show, please go to