Types of Arrhythmia in Children

Abnormal heartbeats, or arrhythmias, in adults can also affect children. In such cases, special considerations may help identify symptoms and treat the condition.

Your doctor may ask your children questions if they have a hard time describing symptoms. The doctor can also ask you about medical and family history. These answers can help establish your child’s risk for arrhythmia. Your doctor may also recommend diagnostic tests for arrhythmia.


Watch animations of several types of arrhythmias.

Long QT Syndrome (LQTS)

Like other arrhythmias, Long QT Syndrome (LQTS) is a disorder of the heart’s electrical system.

When a child has LQTS, the lower chambers of the heart (ventricles) take too long to contract and release. The gap of time needed to complete a cycle can be measured and compared to normal averages for children.

The name for the condition comes from letters associated with the waveform created by the heart’s electrical signals when recorded by an electrocardiogram (EKG or ECG). The interval between the letters Q and T defines the action of the ventricles. “Long QT Syndrome,” then, means that the time gap between the Q and T points on the waveform is too long, even if by fractions of a second.

LQTS can be hereditary, appearing in otherwise healthy children. Other children may acquire LQTS, sometimes as a side effect of medications.

Some arrhythmias related to LQTS can cause sudden cardiac arrest and are potentially fatal. Deafness may also occur with one type of inherited LQTS.

Symptoms of LQTS

Children with LQTS may not have any symptoms. Children who do have symptoms may experience:

  • Fainting (syncope)
  • Irregular heart rate or rhythm
  • Fluttering in the chest

Children with LQTS may experience a longer-than-normal QT interval during physical exercise, when startled by a noise, or when experiencing intense emotion such as fright, anger or pain.

If your child experiences fainting episodes, or if your family has a history of fainting or sudden heart-related death, LQTS should be investigated as a potential cause. Your doctor may recommend an exercise stress test  in addition to an electrocardiogram.

How is LQTS treated?

Treatments for LQTS in children include medications such as beta blockers and surgical procedures such as an implantable cardioverter defibrillator (ICD).

Your child’s doctor may also curtail any drugs known to prolong the QT interval. Other risk factors, such as an electrolyte imbalance, are best avoided as well.

Premature contractions

Premature or extra contractions can cause irregular heart rhythms in children. Premature beats that start in the heart’s upper chambers (atria) are called premature atrial contractions, or PACs. Premature ventricular contractions, or PVCs, start in the ventricles.

When a contraction in either chamber occurs prematurely, there’s usually a pause that causes the next beat to be more forceful. If your child or teenager says their heart “skipped a beat,” it’s typically this more forceful beat that caused that feeling.

Causes and treatment

Premature beats are common in normal children and teenagers.

Usually no cause can be found, and no special treatment is needed. The premature beats may disappear on their own. Even if your child’s premature beats continue for some time, the condition is usually no cause for concern. No restrictions on your child’s normal activities should be warranted.

Occasionally, premature beats may be caused by disease or injury to the heart. If your child’s doctor suspects this may be the case, he or she may recommend additional tests to evaluate your child’s heart health.


Tachycardia refers to a heart rate that’s too fast.

How that’s defined depends on your child’s age and physical condition.

For example, tachycardia in newborns refers to a resting heart rate of more than 160 beats per minute. A teenager is considered to have tachycardia if his or her resting heart rate is higher than 90 beats per minute.

Sinus Tachycardia

Sinus tachycardia is a normal increase in the heart rate. It’s common in children, and usually no treatment is needed. In most cases, sinus tachycardia occurs with fever, excitement or exercise.

Sinus tachycardia can also be caused by increased thyroid activity or conditions such as anemia (low blood count), although rare. In these instances, the tachycardia usually goes away once the underlying condition has been treated.

Supraventricular tachycardia (SVT)

The most common tachycardia in children is supraventricular tachycardia (SVT). It’s also called atrial tachycardia, paroxysmal atrial tachycardia (PAT) or paroxysmal supraventricular tachycardia (PSVT).

When a child has SVT, electrical signals in the heart’s upper chambers (atria) fire abnormally. This interferes with electrical impulses coming from the sinoatrial (SA) node, the heart’s natural pacemaker. This disruption results in a faster than normal heart rate.

SVT in infants

SVT can occur in infants. It’s usually accompanied by a resting heart rate of more than 220 beats per minute. Infants with SVT may also breathe faster than normal, seem fussy or appear sleepier than usual. With proper diagnosis and treatment, SVT is a short-lived condition in infants. Symptoms often disappear within months.

In some cases, SVT can be detected while a baby is still in the womb. An expectant mother may be advised to take medications to slow down her baby’s heart rate.

SVT in children and teens

SVT doesn’t pose a life-threatening problem for most children and adolescents. Treatment is only considered if episodes are prolonged or frequent. Older children are more likely to have SVT.

A child with SVT may be aware of his or her rapid heart rate, as well as other symptoms that include:

  • Heart palpitations
  • Dizziness
  • Lightheadedness
  • Chest discomfort
  • Upset stomach
  • Weakness

In most cases, SVT doesn’t keep a child from enjoying normal activities. Medicine may be necessary to keep the tachycardia under control. Your child’s doctor will also want to see your child periodically to monitor the situation.

Some children can learn ways to slow down their heart rate. For instance, the Valsalva maneuver – closing the nose and mouth and straining to breathe out – may help your child slow his or her heart rate.

Treatment approaches

Treating SVT usually includes focusing on stopping the current episode and preventing recurrences. Your child’s age also helps inform the recommended treatment approach.

SVT treatment options for children include:

  • Medications, including intravenous medications
  • Ablation, using a thin, flexible tube inserted through the nostril
  • Cardioversion, a small electrical shock to the chest wall

Wolff-Parkinson-White Syndrome (WPW)

In this disorder, electrical pathways between the upper chambers (atria) and lower chambers (ventricles) of your child’s heart malfunction, allowing electrical signals to reach the ventricles prematurely.

Those electrical impulses can then be “bounced back” to the atria. This ricocheting of electrical signals can produce overly fast heart rates.

Often medication can improve this condition. In rare cases when medication is not effective, other treatment options include catheter ablation and surgical procedures.

Ventricular tachycardia

Ventricular tachycardia (VT) is a fast heart rate that starts in the lower chambers (ventricles) of your child’s heart.

This condition is uncommon, but potentially very serious. In some cases, ventricular tachycardia can be life-threatening. It requires immediate medical attention.

Ventricular tachycardia may result from serious heart disease. Occasionally, it can occur in children with otherwise normal hearts.

Specialized tests, including an intracardiac electrophysiologic procedure, may be needed to evaluate the tachycardia as well as the effectiveness of medications that treat it. Other possible treatment options include radiofrequency ablation and surgery.

Some forms of ventricular tachycardia may not need treatment.


Bradycardia is a heart rate that’s too slow.

What’s considered too slow depends on a few factors, including your child’s age.

A newborn usually won’t have a heart rate under 80 beats a minute. An athletic teenager could have a normal resting heart rate as low as 50 beats a minute.

Sick Sinus Syndrome

When the sinus (or sinoatrial, or SA) node doesn’t fire its electrical signals properly, the heart rate slows down. This is referred to as sick sinus syndrome. It can cause a heart rate that’s too slow (bradycardia) or too fast (tachycardia).

A child with sick sinus syndrome may be tired, dizzy or faint. Some don’t have symptoms.

This condition is unusual in children. It sometimes affects children who have had open-heart surgery.

Treatment options include medications, an artificial pacemaker or a combination of both.

Complete Heart Block

Heart block occurs when the heart’s electrical signals can’t pass normally from the upper chambers of the heart to the lower chambers. Without electrical impulses from the sinoatrial node, the ventricles will still contract and pump blood, but at a slower rate than usual.

Heart block can be caused by disease or a heart muscle injury sustained during surgery. One type of heart block, congenital heart block, may be present in the womb.

Treating complete heart block may require an artificial pacemaker.

Checklist for parents of children with arrhythmias

Learn to check your child’s heart rate.

You may be asked to check your child’s heart rate to help monitor an arrhythmia.

You can do this by feeling for your child’s pulse, or by listening to the heart with a stethoscope. (Stethoscopes can be purchased online or at some drugstores.) You'll need a clock or watch with a second hand to accurately count the number of beats in one minute. Your doctor can provide other detailed instructions.

Learn to slow your child’s heart rate.

If your child has recurring episodes of tachycardia (fast heart rate), your doctor may teach you and your child ways to slow the heart rate.

Sometimes coughing or gagging is helpful. An ice pack held against the face sometimes works, too. The Valsalva maneuver – closing the nose and mouth and straining to breathe out – can be effective as well.

Always follow the doctor’s recommendations exactly. Don’t be afraid to ask questions if you don’t fully understand the doctor’s instructions.

Understand and manage medications.

Parents of a child taking medicine for an arrhythmia should administer the medications at the right time. Some arrhythmia drugs must be given at regular intervals during the day.

Your doctor will help you determine how to give the medicine, with the least inconvenience to you and your child. Don’t be afraid to ask questions.

Always administer medications exactly as recommended by your doctor. Never stop giving medications without checking with your doctor first.

Learn CPR and emergency procedures.

Parents of all children should learn CPR. You could help save your child’s life, including in cases of sudden infant death syndrome (SIDS). 

CPR skills, including recognition of signs of breathing difficulties and cardiac arrest, are vital if your child has heart disease or is at risk for life-threatening arrhythmias.

Understand and manage your child's implanted device.

If your child has an implantable cardioverter defibrillator (ICD) or a pacemaker, your doctor or nurse will give you detailed information about the device and how to check it.

If your child has a pacemaker, a special device lets you use the phone to transmit a signal from the pacemaker to your doctor. This provides your doctor with insight into your device’s day-to-day functioning. If there’s an issue, someone from your doctor’s office will contact you and tell you what to do.

There are similar considerations for an ICD. Your doctor will want to check the device periodically to assess its battery and overall effectiveness.

With either device, it’s important that you and your child both carry an ID card that alerts medical personnel about his or her implanted device. The presence of an ICD or a pacemaker in your child’s body might prohibit some medical procedures, including those that use strong electromagnetic fields.

Learn more:

Know what to avoid

It’s important for you and your child to be aware of activities or medicines that might cause an arrhythmia. Your child’s doctor or nurse should talk to you about what to avoid.

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