What is arrhythmia?

Arrhythmia (pronounced a-RITH-me-ah) is an abnormal heart rhythm.

Typically, this means a child’s heart is beating too fast or too slow for the activity they are doing. In some children, an abnormal heartbeat may have serious consequences. But in many cases, symptoms may be bothersome but not a cause for concern.

Arrhythmias are caused by a problem with the electrical system in the heart. This can lead to a heartbeat that’s too fast (tachycardia, pronounced tack-ih-CARD-ee-ah) or too slow (bradycardia, pronounced brad-ih-CARD-ee-ah).

    • The heart has 4 chambers that work like a pump. The atria are the 2 top chambers. They receive blood from the lungs and the rest of the body. The ventricles are the 2 bottom chambers. They pump blood out to the lungs and the rest of the body. It is important for all 4 chambers of the heart to work in sequence with one another to create an effective pump.
    • The sinus node is known as the “pacemaker” of the heart. It works to control the normal heart rate. It’s located at the top of the right atrium. The sinus node makes the heart beat slower during times of rest or sleep and beat faster with exercise or when you are scared or excited.
    • Each heartbeat begins with an electrical wave (signal) that passes from the sinus node through the upper chambers of the heart. This signal travels much like the ripples created in water when a pebble is thrown in. This electrical signal makes the chambers (atria) contract, or squeeze, making them beat.
    • Next, the electrical signal moves into the junction between the upper and the lower chambers. This junction is known as the atrioventricular node (AV node). The AV node delays the signal slightly and then passes it on to the lower chambers (ventricles), making them beat.
    • After the ventricles beat, the heartbeat cycle is complete. There should be no way for the electrical signal to travel backwards up to the atria. Rather, the next heartbeat starts in the sinus node and follows the same path.
  • There are many kinds of arrhythmia that affect the chambers of the heart in different ways. Some are harmless, and some are serious. Children with signs or symptoms of arrhythmia should be evaluated by a heart doctor (cardiologist).

    Sometimes arrhythmias are present at birth (congenital), and others are acquired, such as after an infection of the heart or heart surgery.

    For example, supraventricular tachycardia (SVT) is the most common cause of a fast heartbeat and is usually not life threatening. In contrast, long Q-T syndrome (LQTS) is a genetic condition associated with life-threatening arrhythmias that may be triggered by exercise or by being startled or frightened.

    In other cases, such as after heart surgery, the heart’s normal electrical system may become scarred and not function normally. It may cause very rapid heartbeats or a heartbeat that’s too slow for the child’s level of activity.

Arrhythmia at Seattle Children’s

  • Our Arrhythmia Program provides comprehensive treatment and evaluation to children and teens with heart rhythm problems—from the simple to the complex. We offer the full range of treatment options, including:

    We have state-of-the-art facilities to maximize safety, including low- or no-radiation procedures. A pediatric cardiac anesthesia team makes sure that your child is comfortable and safe during arrhythmia procedures.

    Seattle Children’s Heart Center is one of the best pediatric cardiology programs in the United States and is the top-ranked program in the Northwest, according to U.S. News & World Report. With more than 40 pediatric cardiologists, we have experience diagnosing and treating every kind of heart problem.

  • When you come to Seattle Children’s, a team of people will take care of your child. Along with your child’s heart doctor (cardiologist), you are connected with newborn specialists (neonatologists), nurses, child life specialists, social workers and others, if their expertise is needed. Our pediatric cardiac anesthesia team makes sure that your child is comfortable and safe during arrhythmia procedures.

    Our team members are trained in their fields and in meeting the unique needs of children. For example, the doctors who give your child anesthesia are board certified in pediatric anesthesiology. This means they have extra years of training in how to take care of kids. Our child life specialists know how to help children understand their illnesses and treatments in ways that make sense for their age.

    We work together to meet all of your child’s health needs and help your family through this experience. We’ll discuss treatments in ways you can understand and involve you in every decision.

    Read more about the supportive care we offer.

Symptoms of Arrhythmia

Arrhythmia can cause these problems with your child’s heartbeat:

  • Heart beats too slowly (bradycardia, pronounced brad-ih-CARD-ee-ah).
  • Heart beats too quickly (tachycardia, pronounced tack-ih-CARD-ee-ah).
  • Heartbeat is irregular – the speed and pattern change.

You and your child might not notice any problems with their heartbeat. Sometimes families have no idea their child has an arrhythmia until it is noticed during a routine exam.

Because the heartbeat affects blood flow, some arrhythmias can cause these signs and symptoms:

  • A sense of an unusual heartbeat (palpitations)
  • Feeling faint, weak, lightheaded or dizzy
  • Being short of breath
  • Tiring easily
  • Having chest pain
  • Sweating
  • Pale or ashen skin

Diagnosing Arrhythmia

To diagnose this condition, your doctor will examine your child, check their heartbeat and use a stethoscope to listen to their heart. The doctor will ask for details about any symptoms your child has, their health history and your family health history.

Some kinds of arrhythmia happen only once in a while. When they are not happening, they can be difficult to detect. For this reason, arrhythmias can be hard to diagnose.

To learn about the electrical activity in your child’s heart, the doctor will use an electrocardiogram (ECG). If an abnormal heartbeat does not happen during this test, your child may be asked to wear a monitoring device at home. Depending on the nature of your child’s symptoms and your child’s age, the appropriate monitor will be selected:

  • For daily symptoms, a device called a Holter monitor is typically used. This monitor can record the heart’s activity for 24 hours.
  • For less frequent symptoms, another device called an event monitor can be activated by you or your child when they feel a problem with their heart rhythm.

Other common tests to evaluate arrhythmia include:

Our doctors also use electrophysiology studies, which enable them to find the cause of the arrhythmia and, in many cases, cure it.

Treating Arrhythmia

Your child may not need any treatment for arrhythmia. Often, an abnormal heartbeat does not cause any problems. If your child does need treatment, there may be several options, depending on the kind of arrhythmia.

The need for treatment depends on many factors, including:

  • The kind of arrhythmia
  • The age of your child
  • The duration and frequency of the episodes
  • Whether your child has symptoms
  • Arrhythmias may be treated with 1 or more of these options, depending on the kind of arrhythmia and how serious it is:

    • Observation (monitoring over time without treatment)
    • Medicines that correct the heart rate or make an irregular heartbeat steady
    • Transcatheter ablation: A procedure that uses a small tube (catheter) guided through the blood vessels of the leg up to the heart. The catheter is used to destroy a tiny piece of the heart tissue that is causing the arrhythmia.
    • Pacemaker implantation
    • Defibrillator implantation
    • Surgery

    Read more about the treatment options we offer through our Arrhythmia Program.

Contact Us 

Contact the Heart Center at 206-987-2515 to request an appointment, a second opinion or more information.

Providers, see how to refer a patient.