A child's heart beating fast — palpitations or the sensation of an irregular heartbeat — can be caused by a number of conditions, not all of them serious.

Published: February 24, 2023

What to do if your child’s heart is beating abnormally fast or irregularly

A child whose heart is beating fast or irregularly often won’t have the vocabulary to describe what’s happening.  While an adult may be able to say “I am having palpitations”, children may describe vague chest symptoms, a fluttering or racing heart or skipped heartbeats.  They may say, “My heart is beating out of my chest,” or “My heart is beeping really fast.”

Toddlers may just grab their chest, appear uncomfortable or cry without an obvious cause, or just seem pale or upset. Little babies may be irritable for no reason, have trouble breathing, refuse to eat or vomit after eating.

“Abnormal heartbeats or arrhythmias can happen in children with a known history of a heart problem, but also can occur in children previously thought to be healthy,” said Brian J. Holland, M.D., pediatric cardiologist with Norton Children’s Heart Institute, affiliated with the UofL School of Medicine. “Sometimes when a child feels like their heart is beating fast, it may not be due to a heart problem at all.  Many times their heart is normal and healthy, and it is just beating faster than usual because of something else that is happening in their body.  A child may notice that their heart is beating fast if they are nervous or scared, they have a fever, they have had too much caffeine, they have taken a stimulant medication, they have been running or exercising, or if they have another medical condition such as low blood sugar or a low blood count.”

If it doesn’t seem like an emergency, start with your pediatrician or other primary care provider. The provider likely will ask you for more details about the symptoms and do a thorough physical examination. If the provider suspects the palpitations possibly are caused by an underlying heart issue, you may be referred to a pediatric cardiologist or arrhythmia specialist.

To help the primary care provider or cardiologist sort out a child’s heart beating fast, consider these questions:

• When was the first time the child’s heart beating fast or irregularly was noticed?
• How often (for example, once a week or twice in six months, etc.) and for how long (for example, seconds, minutes or longer) do these episodes seem to last?
• Are there certain circumstances when these symptoms usually occur (for example, only with a fever or prolonged exercise, or happening completely randomly)?
• Do the palpitations start and then go away all of a sudden (like flipping a light switch), or do they seem to start out or ease off more gradually?
• Have you or your child found any specific activity, such as bearing down or coughing, that seems to stop an episode?
• Are there any other symptoms that occur around the same time, such as feeling dizzy or lightheaded, chest pain, trouble breathing, vomiting, headaches or fainting?

How to take your child’s pulse

If you child is complaining of a racing heart, dizziness or chest pain, you can take their pulse. This is helpful information for their medical provider.

The best spot to feel the pulse in an infant is the upper arm. Lay your baby down on the back with one arm bent so the hand is up by the ear. Feel for the pulse on the inner arm between the shoulder and the elbow. The best spot to feel the pulse in a child is the wrist. Gently feel on the inside of the wrist on the thumb side. If you can’t easily find the pulse on the wrist, you can try the neck. Gently place your fingers on one side of the windpipe.

3 steps to take a child’s pulse:

1. Gently press two fingers (don’t use your thumb) on the spot until you feel a beat.
2. When you feel the pulse, count the beats for 15 seconds.
3. Multiply the number of beats you counted by 4 to get the beats per minute.

When to go to the hospital for rapid heart rate

If your child has palpitations or abnormal heartbeats and doesn’t appear well, especially if the episode is persistent, seek medical attention immediately.

Go to an emergency room or call 911 right away if your child has symptoms such as racing heart, dizziness, chest pain or fainting and:

• Is hard to wake up
• Has trouble breathing (Look for muscles pulling in between the ribs or the nose puffing out with each breath.)
• Has pale or gray skin, or blue lips