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Our Cardiac Arrhythmia team cares for children, teenagers and young adults with abnormal heart beats and rhythms.

If you've ever listened to the sound of a healthy heart, it has a natural rhythm or beat, kind of like a drum in music band. But sometimes, that rhythm can get off beat, going too fast or too slow, skipping beats or adding in extra beats. These irregularities may be temporary or benign (not life threatening).. However, at other times, these irregularities may be a sign of serious congenital heart abnormalities.

What causes it?

Heart Center
What's a normal heart rate?

Typical normal resting heart rate ranges are:

Babies (birth to 3 months of age): 95-180 beats per minute

Kids 1-3 years old: 80-150 beats per minute

Kids by age 12: 50-110 beats per minute

These are estimates based on average normal rates by age, but are not meant to represent a diagnosis nor an indicator of overall health.

Arrhythmias are abnormalities in the heart rhythm, such as tachycardia (rapid heart rate) and bradycardia (slow heart rate). The heart has its own conduction system, or electrical system, that sends electrical signals around the heart, telling it when to contract and pump blood throughout the body. The electrical signals originate from a group of cells in the right atrium, called the sinus node. The sinus node functions as the heart's pacemaker and makes sure the heart is beating at a normal and consistent rate. The sinus node normally increases the heart rate in response to factors like exercise, emotions and stress, and slows the heart rate during sleep.

Sometimes the electrical signals flowing through the heart don't "communicate" properly, and the heart can start beating in an abnormal pattern – an arrhythmia (also called dysrhythmia).

Arrhythmias can be temporary or permanent. They can be caused by several things, but the most common arrhythmias occur in children with structurally normal hearts that were born with an extra electrical connection (or pathway).

Other causes of arrhythmias in kids include:

  • Chemical or electrolyte imbalances in the blood
  • Infections or diseases that cause irritation or inflammation of the heart
  • Medications – prescription or over-the-counter
  • Injuries to the heart from chest trauma or heart surgery
  • Illegal drugs, alcohol, tobacco, caffeine, stress and some herbal remedies also cause arrhythmias
  • Structural heart defects
  • Genetic abnormalities

Who gets it?

Arrhythmias can occur in anyone, regardless of ethnicity or socioeconomic status. And they can occur at any stage of life. A child may be born with it or it may develop well into the adult years. Some common risks include:

  • Congestive heart failure
  • Heart surgery
  • Congenital heart disease
  • Genetic disorders
  • Metabolic disorders
  • Over-the-counter medicines and some herbal remedies
  • Prescription and therapeutic medications, including chemotherapy and radiation therapy
  • Sleep disorders, especially sleep apnea
  • Stimulants (such as too much caffeine)
  • Alcoholic beverages, illegal drugs


Because arrhythmias can cause the heart to beat less effectively, blood flow to the brain and to the rest of the body can be affected. If the heart is beating too fast, its chambers can't fill with the proper amount of blood. If it's beating too slowly or irregularly, the proper amount of blood can't be pumped out to the body.

If the body doesn't get the supply of blood it needs to run smoothly, the following symptoms can occur:

  • Dizziness
  • Fatigue
  • Lightheadedness
  • Weakness
  • Palpitations (a feeling of fluttering or pounding in the chest)
  • Shortness of breath
  • Chest pain
  • Fainting

Arrhythmias can be constant or come and go. Sometimes arrhythmias don't cause any symptoms and are only heard by your child's doctor during a routine exam. If your doctor does suspect an arrhythmia, an evaluation by a pediatric cardiologist is recommended.

Care and treatment information

Cook Children's Heart Center offers electrophysiology studies, ablation procedures (erasing tissue where the short circuit is occurring), pacemaker implantation (a device that triggers the heart to beat) and defibrillators (a device that sends electricity to the heart to restore a normal rhythm), as well as follow-up.

Electrophysiology studies are tests that examine the electrical activity in the heart. They help determine the type and location of a specific arrhythmia. If certain arrhythmias are found, radiofrequency catheter ablation (RFCA) and cryoablation can be used to eliminate the abnormality.

Catheter ablation is often used to correct abnormal heartbeats or arrhythmias. Our cardiologists excel in the use of RFCA for children and young adults.

Cardiologists use a detailed view of the heart to identify abnormal tissue that is the cause of an irregular heartbeat. Cook Children's was the first pediatric facility in the U.S. to use EnSite 3000® computerized mapping and imaging software to help identify the source of an arrhythmia.

A catheter (a narrow, flexible wire) is inserted through a vein, then the catheter is routed to the heart and to the site of the arrhythmia. Electromagnetic Radiofrequency energy, or cryotherapy, eliminates abnormal tissue and leaves surrounding healthy tissue unaffected. Following ablation, many children are able to enjoy healthy lives without heart problems.


  • Supraventricular tachycardia
  • Wolff-Parkinson-White syndrome
  • Premature atrial and ventricular contractions
  • Ventricular tachycardia
  • Palpitations or fluttering chest sensations due to abnormal rhythms
  • Cardiac conduction defects or unstable electrical system failures, such as Long QT syndrome
  • Syncope (near-death fainting or dizzy spells)
  • Slow heart rate conditions, such as heart block

Most arrhythmias are temporary and cause no harm to the heart, and they occur most often in adults. However, an arrhythmia may indicate a serious condition which, if left untreated, could result in heart failure and even become life threatening. The pediatric cardiologists in our Heart Center are experts in the care and treatment of arrhythmias in growing hearts, focusing on the most important thing of all ... your child.

Appointments and referrals

Rare and complex congenital heart defects don’t always present a clear cut method of treatment. Often, there are multiple ways of approaching the diagnosis. Our physicians also are available to provide second opinions for families seeking alternative treatment options. If you would like to schedule an appointment, refer a patient or speak to our staff, please call our offices at 682-885-2140.