About Arrhythmias in Children

  • The average heartbeat for an infant is 140 beats per minute; average heartbeat for an older child or teenager is 70 beats per minute.
  • The human heart beats more than 2.5 billion times in an average lifetime.
  • Arrhythmias can happen at any age but are more common in adults than in children.
  • Sinus arrhythmia is a harmless arrhythmia in some children whose heart speeds up and slows down when they breathe in and out.

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What is an arrhythmia?

An arrhythmia is any irregularity in the heart’s normal, even beat. Your child may be diagnosed with an arrhythmia if his or her heart is beating too fast or too slow, is skipping beats, or has extra beats. Most arrhythmias in children are harmless but it is important to have them properly evaluated. Arrhythmias that are the result of serious conditions or heart defects can be life threatening.

The heart’s four chambers—the atria and the ventricles—expand and contract to pump blood to the lungs and the rest of the body in a highly regulated manner that is governed by a complex electrical system. When this system works, the heart pumps at a regular, even rate. A normal heartbeat will usually increase when a child is playing, crying, or has a fever, and decreases when the child is at rest. 

Any interruption in this finely-tuned electrical circuit will cause an arrhythmia. Arrhythmias that affect the heart’s ability to pump blood efficiently to the rest of the body can be serious, and can damage organs including the kidneys, liver, heart, and brain.

What causes arrhythmias in children?

Arrhythmias can be the result of a genetic heart defect or a disease of the heart muscle. They can also be exacerbated by fevers, medications, or infections. A cardiologist who has experience with heart rhythm problems can determine the cause of your child’s arrhythmia through a series of tests. Your cardiologist may recommend genetic counseling to confirm a diagnosis and to inform family members about the condition. 

What are the symptoms of arrhythmias in children?

Your child’s arrhythmia may be detected by his or her pediatrician, or your child may experience symptoms. Your child’s ability to explain symptoms will depend on his or her age. 

Symptoms of arrhythmias in children include:

  • Weakness
  • Fatigue
  • Heart palpitations
  • Lightheadedness or dizziness
  • Low blood pressure
  • Fainting or almost fainting
  • Paleness
  • Difficulty feeding (in infants)
  • Slow heartbeat
  • Fast heartbeat
  • Heartbeat that skips

Types of arrhythmias in children

The word arrhythmia describes a range of conditions that affect the heart rate. A heartbeat that is too fast is called a tachycardia. A heartbeat that is too slow is called a bradycardia. Specific heart rhythm conditions that occur in children include:

  • Brugada syndrome
  • Catecholoaminergic polymorphic ventricular tachycardia
  • Fetal arrhythmias
  • Heart block
  • Hypertrophic and dilated cardiomyopathy
  • Long QT syndrome/short QT syndrome
  • Supraventricular tachycardia
  • Ventricular tachycardia
  • Wolff-Parkinson-White syndrome

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