Transcription:
Pediatric Heart Palpitations

Melanie Cole (Host):  When children or adolescents present complaints of heart palpitations, this can be a very vague term and could mean anything. A smaller child may even have difficulty putting into words what he or she is feeling during a heart palpitation. My guest today is Dr. Jennifer Silva. She's a Washington University pediatric cardiologist at St. Louis Children's Hospital, and the director of pediatric electrophysiology. Welcome to the show, Dr. Silva. What is a heart palpitation and how does it generally present with patients?

Dr. Jennifer Silva (Guest):  I think that's a great question. And the truth of the matter, is heart palpitations are whatever the child is experiencing, and I think it's really critical for us to let the children tell us what they're feeling. Kids can be really creative and use some really great words that will tell us exactly what the problem is. So it's really common for little girls, for instance, to describe a heart palpitation as something that feels like a butterfly flapping their wings really quickly inside of their chest. So that to me means, okay, not only are they feeling their heart beating hard, they're feeling it beating quickly. So just allowing the kids to use words that they know in their natural vocabulary can be really important in telling us what's happening.

Melanie:  Are you generally seeing this more commonly in boys or girls?

Dr. Silva:  We see it in both genders. We certainly know that, at certain age groups, certain genders are more in tune with their bodies, and so we do see more adolescent girls, for instance, who just are more aware of what's happening with their body, and so they tend to be more vocal about those things. But this is certainly not gender predominant one way or the other.

Melanie:  So what would send up a red flag that would ask a pediatrician to refer on a child's heart palpitations if you're looking for anemia or thyroid problems?

Dr. Silva:  I get really worried when there are other issues happening around the time of the palpitations. For instance, if a child says that they feel like they're going to pass out, or if they actually do pass out with one of these episodes. That's a red flag, and that's a child that I actually want to see. Additionally, if the parents are telling you that there's a family history of something very dramatic like sudden death, those kids need to get evaluated immediately.

Melanie:  When children are in the pediatric office, is this something that presents at the time of visit, or are they telling you about something that happened before?

Dr. Silva:  Often they're telling us something that happened before, and as we start probing the child, we can find out that maybe these symptoms have happened multiple times in the past, but for whatever reason they never brought it to the attention of their parents or their pediatrician until something changed in the character or the nature of the events that made them want to tell an adult.

Melanie:  So if a pediatrician refers, then what is the next step for a pediatric cardiologist?

Dr. Silva:  Often we will start with a really thorough history, and that's going to include a very thorough family history to see if there are any sort of genetic components that could be contributing to the episodes. We'll also do a thorough physical exam and then we'll start with some ampullary testing. For instance, almost every single one of these kids is going to need an electrocardiogram, and there’s the need that EKG interpreted by a pediatric cardiologist. So we'll start there. If we have further concerns that may warrant a further test like an echocardiogram, on some kids, if they're having very frequent symptoms, we may recommend a 24- or 48-hour Holter monitor. And for kids who are having less frequent symptoms, we might think about some sort of event monitor.

Melanie:  What would be worrisome on the EKG or the echo?

Dr. Silva:  There are certain intervals that we calculate on the EKG, and I think it's incredibly important that we measure things like the QT interval. We're also looking for things like AXIS, ST, and T wave segment changes. We're looking for hypertrophy of certain chambers. So it's a really thorough and detailed analysis on the EKG. Any of those things are red flags and are going to warrant some sort of further testing. The kind of abnormality is going to dictate whether we put that kid straight that day for an echocardiogram, and we recommend for an exercise stress test or other thorough monitoring.

Melanie:  And what do you do if you detect something worrisome? What is the next line of treatment?

Dr. Silva:  That's a great question, and it really is going to depend on what we find and what we think is in the best interest for that patient. So if we detect that a patient has an abnormal heart rhythm and we've recorded it, that might be a kid that we want to send for an invasive electrophysiology study and catheter based ablation. We may find that some kids need more intensive monitoring and need something like an implantable loop recorder. We may find that some of these kids need medication and it's a matter of starting that child on medication. Many of our kids we can start in an outpatient setting, but some do need to become inpatients for that.

Melanie:  And what are some of the new technologies in treatments for heart palpitations in children?

Dr. Silva:  There are all sorts of monitors that we can use. Some are external monitors and some are internal monitors. There's been a lot of great modifications recently on the internal monitors, and now they're quite small, quite sleek, and have a really long battery life. So those implantable loop recorders have a 3-year battery life, so patients with very infrequent symptoms may benefit from that kind of a technology.

Melanie:  Tell us about SVT in children, and can this occur in children of any age, including newborns?

Dr. Silva:  SVT is an abnormal heart rhythm where, instead of the normal heartbeat going from the atria down to the ventricles, it acts in a reentry circuit, or in a circular sort of loop. It's seen in all age groups. It can be seen from newborns up until kids are aging out of our practices. What we do know is that a third of infants that have SVT may outgrow it in the first year or two of life. But what that means is that two thirds of those infants are going to continue having their SVT. We also know that catheter based ablation procedures can be done pretty safely in kids once they're bigger than 15 kilos. So we know that there is a definitive therapy with a very high cure and success rate — over 90% for these patients — and it's a matter of determining when is the appropriate time for patients to have that procedure and if they need that procedure.

Melanie:  How do you try and record the rhythm during the episode if it's not that easy of an exercise to do, if it's unpredictable?

Dr. Silva:  I think that's a great question, and this links back into what our technologies are. So, we do have Holter monitors, and Holter monitors are monitors that kids wear for either 24 or 48 hours, and it records every single heartbeat they have. So kids who are having really frequent symptoms will tell you that every day, multiple times a day, “I have this sensation of palpitations.” That may be a good next step. For kids who come in and say, “I don't have symptoms but for every month or two months,” then maybe an event recorder, which is a device that they keep with them and simply put up to their chest and record a tracing when they're having one of those symptoms. Maybe that's the better sort of tool for that kind of patient. For kids that have exceptionally rare episodes but that are incredibly worrisome or bothersome, then we would think about something like an implantable loop recorder.

Melanie:  And tell us about your team. Why is St. Louis Children's Hospital so great to work with?

Dr. Silva:  We are a fantastic team. We have three practicing interventional pediatric electrophysiologists and a dedicated pediatric electrophysiology nurse practitioner. We're available to answer questions for pediatricians 24 hours a day, 7 days a week. We have clinics both here in the city and at the West County location. Additionally, we have a multi-disciplinary inherited arrhythmia clinic which is specifically designed to care for patients and families who have inherited arrhythmias, and that's a clinic where patients have the ability to see cardiology, genetics, and psychology as needed.

Melanie:  And to wrap it up, Dr. Silva, what would you like to tell other pediatricians about when to refer for a heart palpitation in children that they may see in their practice?

Dr. Silva:  I want to start by saying we are always happy to see any kids that are worrisome to the general pediatrician, and we're available 24/7 to them. We have a great team. We have three interventional pediatric electrophysiologists. We also have a dedicated electrophysiology nurse practitioner, and so we're always available to answer questions.

Melanie:  Thank you so much for being with us today. A physician can refer a patient by calling Children's Direct Physician Access Line at 1-800-678-HELP. That's 1-800-678-4357. You're listening to Radio Rounds with St. Louis Children's Hospital. For more information on resources available at St. Louis Children's Hospital, you can go to stlouischildrens.org. That's stlouischildrens.org. This is Melanie Cole. Thanks so much for listening.